Changes that occur to liberate the enzymes of the ACROSOME of a sperm (SPERMATOZOA). Acrosome reaction allows the sperm to penetrate the ZONA PELLUCIDA and enter the OVUM during FERTILIZATION.
The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.
Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.
The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.
A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.
Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.
A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.
The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
Proteins which are found in eggs (OVA) from any species.
Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.
An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.
Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.
The plasma membrane of the egg.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
A genus of STARFISH in the family Asteriidae. One species, Asterias rubens, is the most common in the north-east Atlantic region.
The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.
A TETRACYCLINE with a 7-chloro substitution.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).
A diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to HALOPERIDOL for the suppression of vocal and motor tics in patients with Tourette syndrome. Although the precise mechanism of action is unknown, blockade of postsynaptic dopamine receptors has been postulated. (From AMA Drug Evaluations Annual, 1994, p403)
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.
The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. In addition to reproductive organ secretions, it contains SPERMATOZOA and their nutrient plasma.
The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
Proteins found in SEMEN. Major seminal plasma proteins are secretory proteins from the male sex accessory glands, such as the SEMINAL VESICLES and the PROSTATE. They include the seminal vesicle-specific antigen, an ejaculate clotting protein; and the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.
The most abundant member of the RAB3 GTP-BINDING PROTEINS. It is involved in calcium-dependent EXOCYTOSIS and is localized to neurons and neuroendocrine cells. This enzyme was formerly listed as EC
The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.
Chemical agents that increase the permeability of CELL MEMBRANES to CALCIUM ions.
A species of the true toads, Bufonidae, found in South America.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
The maturing process of SPERMATOZOA after leaving the testicular SEMINIFEROUS TUBULES. Maturation in SPERM MOTILITY and FERTILITY takes place in the EPIDIDYMIS as the sperm migrate from caput epididymis to cauda epididymis.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.
A benzimidazole antifilarial agent; it is fluorescent when it binds to certain nucleotides in DNA, thus providing a tool for the study of DNA replication; it also interferes with mitosis.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.
A polyether antibiotic which affects ion transport and ATPase activity in mitochondria. It is produced by Streptomyces hygroscopicus. (From Merck Index, 11th ed)
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
A genus of the family Muridae having three species. The present domesticated strains were developed from individuals brought from Syria. They are widely used in biomedical research.
Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
A slightly alkaline secretion of the endocervical glands. The consistency and amount are dependent on the physiological hormone changes in the menstrual cycle. It contains the glycoprotein mucin, amino acids, sugar, enzymes, and electrolytes, with a water content up to 90%. The mucus is a useful protection against the ascent of bacteria and sperm into the uterus. (From Dictionary of Obstetrics and Gynecology, 1988)
Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.
The middle piece of the spermatozoon is a highly organized segment consisting of MITOCHONDRIA, the outer dense fibers and the core microtubular structure.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The capacity to conceive or to induce conception. It may refer to either the male or female.
Agglutination of spermatozoa by antibodies or autoantibodies.
Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.
Glycoproteins found on the membrane or surface of cells.
A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.
A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.
The quality of SEMEN, an indicator of male fertility, can be determined by semen volume, pH, sperm concentration (SPERM COUNT), total sperm number, sperm viability, sperm vigor (SPERM MOTILITY), normal sperm morphology, ACROSOME integrity, and the concentration of WHITE BLOOD CELLS.
Shrews are small, insectivorous mammals belonging to the family Soricidae, characterized by their pointed snouts, tiny eyes, and rapid movements.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
The fluid surrounding the OVUM and GRANULOSA CELLS in the Graafian follicle (OVARIAN FOLLICLE). The follicular fluid contains sex steroids, glycoprotein hormones, plasma proteins, mucopolysaccharides, and enzymes.
A count of SPERM in the ejaculum, expressed as number per milliliter.
Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge, but may differ in mass or number of neutrons.
A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.
An antiprotozoal agent produced by Streptomyces cinnamonensis. It exerts its effect during the development of first-generation trophozoites into first-generation schizonts within the intestinal epithelial cells. It does not interfere with hosts' development of acquired immunity to the majority of coccidial species. Monensin is a sodium and proton selective ionophore and is widely used as such in biochemical studies.
The emission of SEMEN to the exterior, resulting from the contraction of muscles surrounding the male internal urogenital ducts.
Fucose is a deoxyhexose sugar, specifically a L-configuration 6-deoxygalactose, often found as a component of complex carbohydrates called glycans in various glycoproteins and glycolipids within the human body.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Carbohydrates covalently linked to a nonsugar moiety (lipids or proteins). The major glycoconjugates are glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. (From Biochemical Nomenclature and Related Documents, 2d ed; From Principles of Biochemistry, 2d ed)
A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
A METHYLXANTHINE derivative that inhibits phosphodiesterase and affects blood rheology. It improves blood flow by increasing erythrocyte and leukocyte flexibility. It also inhibits platelet aggregation. Pentoxifylline modulates immunologic activity by stimulating cytokine production.
Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.
Inbred ICR mice are a strain of albino laboratory mice that have been selectively bred for consistent genetic makeup and high reproductive performance, making them widely used in biomedical research for studies involving reproduction, toxicology, pharmacology, and carcinogenesis.
Passive or active movement of SPERMATOZOA from the testicular SEMINIFEROUS TUBULES through the male reproductive tract as well as within the female reproductive tract.
The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A phosphoinositide phospholipase C subtype that is structurally defined by the presence of an N-terminal pleckstrin-homology and EF-hand domains, a central catalytic domain, and a C-terminal calcium-dependent membrane-binding domain.
A highly fluorescent anti-infective dye used clinically as a topical antiseptic and experimentally as a mutagen, due to its interaction with DNA. It is also used as an intracellular pH indicator.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.
An enzyme that catalyzes the random hydrolysis of 1,4-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. (From Enzyme Nomenclature, 1992) There has been use as ANTINEOPLASTIC AGENTS to limit NEOPLASM METASTASIS.
Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Liquid components of living organisms.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.
Serum albumin from cows, commonly used in in vitro biological studies. (From Stedman, 25th ed)

Changes in hyaluronidase, acrosin, and N-acetylhexosaminidase activities of dog sperm after incubation. (1/514)

Hyaluronidase, acrosin and N-acetylhexosaminidase activities were examined in sperm collected from 12 beagle dogs and in culture medium after 0.5 hr and 7 hr of sperm incubation. The activities of the three enzymes were significantly higher at 7 hr than at 0.5 hr (P < 0.05, 0.01), and the increases were associated with sperm capacitation. It was considered that the three enzymes in the dog sperm are related to fertilization by reason of the findings of the release of these enzymes from the sperm into the medium after 7 hr of incubation.  (+info)

Voltage-operated Ca2+ channels and the acrosome reaction: which channels are present and what do they do? (2/514)

Evidence from pharmacological studies suggests that induction of the acrosome reaction of mammalian spermatozoa by solubilized zona pellucida, and possibly by progesterone, is dependent upon Ca2+ influx through voltage-operated Ca2+ channels. Studies on Ca2+ accumulation and membrane potential in ligand-stimulated or artificially depolarized spermatozoa support such a conclusion. Electrophysiological studies on rodent spermatogenic cells have revealed the presence of a 'T' type voltage-operated Ca2+ current. This current has pharmacological attributes consistent with those of the putative channel responsible for Ca2+ influx mediating the acrosome reaction. However, use of molecular techniques to study human and rodent testis and spermatogenic cells has detected the presence of three different voltage-operated Ca2+ channel subunits. One of these (alpha lE) may generate T-currents, though this is currently disputed. Voltage-operated Ca2+ channel structure and the relationship between channel subunit expression and the characteristics of consequent Ca2+ currents is briefly reviewed. The nature and function of T-channel-mediated Ca2+ influx is examined in the context of the time-course of ligand- and depolarization-induced elevation of [Ca2+]i in mammalian spermatozoa. It is likely that a secondary Ca2+ response (mobilization of stored Ca2+ or activation of a second Ca(2+)-influx pathway) is required for the acrosome reaction. Evidence for the existence and participation of various candidates is discussed (including voltage-operated Ca2+ channels, which may be functionally expressed only in mature spermatozoa), the available evidence favouring a secondary Ca(2+)-influx pathway. Immediate priorities for future research in this area are proposed.  (+info)

Ion channels in sperm physiology. (3/514)

Fertilization is a matter of life or death. In animals of sexual reproduction, the appropriate communication between mature and competent male and female gametes determines the generation of a new individual. Ion channels are key elements in the dialogue between sperm, its environment, and the egg. Components from the outer layer of the egg induce ion permeability changes in sperm that regulate sperm motility, chemotaxis, and the acrosome reaction. Sperm are tiny differentiated terminal cells unable to synthesize protein and difficult to study electrophysiologically. Thus understanding how sperm ion channels participate in fertilization requires combining planar bilayer techniques, in vivo measurements of membrane potential, intracellular Ca2+ and intracellular pH using fluorescent probes, patch-clamp recordings, and molecular cloning and heterologous expression. Spermatogenic cells are larger than sperm and synthesize the ion channels that will end up in mature sperm. Correlating the presence and cellular distribution of various ion channels with their functional status at different stages of spermatogenesis is contributing to understand their participation in differentiation and in sperm physiology. The multi-faceted approach being used to unravel sperm ion channel function and regulation is yielding valuable information about the finely orchestrated events that lead to sperm activation, induction of the acrosome reaction, and in the end to the miracle of life.  (+info)

Detection of partial and complete acrosome reaction in human spermatozoa: which inducers and probes to use? (4/514)

The acrosome reaction (AR), an essential step for achieving mammalian fertilization, was recently introduced as a means of clinical evaluation of male fertility. However, most of the available techniques for acrosomal status assessment (except those employing electron microscopy) do not define whether the measurements represent partial or complete AR. We, therefore, performed a crossover investigation of the types of inducers and probes required for detecting partial or complete AR in human spermatozoa. The acrosomal status before and after stimulation with four AR inducers was evaluated after incubation for 3 h in capacitating conditions. We used a fluorescence-activated cell sorter with fluorescein isothiocyanate-conjugated monoclonal antibody CD46 (FITC-CD46) targeting the inner acrosomal membrane for detecting a complete AR, and fluorescein isothiocyanate-Pisum sativum agglutinin (FITC-PSA) targeting the acrosomal content for detection of both partial and complete AR. Without stimulation or following stimulation with progesterone, follicular fluid (FF) or phorbol myristate ester (PMA), the AR could be detected with FITC-PSA but not with FITC-CD46. Following stimulation with the calcium ionophore A23187, the AR could be detected by both FITC-PSA and FITC-CD46. These results suggest that spontaneous AR as well as AR induced by progesterone, PMA and FF are partial. In contrast, the AR induced by A23187 is total, i.e. both partial and complete. These findings are valuable for both research and clinical purposes and are a step towards an international agreement on a standard test for human sperm AR, for which there is an urgent need.  (+info)

Synthesis, characterization and preclinical formulation of a dual-action phenyl phosphate derivative of bromo-methoxy zidovudine (compound WHI-07) with potent anti-HIV and spermicidal activities. (5/514)

In a systematic effort to develop a microbicide contraceptive capable of preventing transmission of human immunodeficiency virus (HIV), as well as providing fertility control, we have previously identified novel phenyl phosphate derivatives of zidovudine (ZDV) with 5-halo 6-alkoxy substitutions in the thymine ring and halo substitution in the phenyl moiety respectively. Here, we describe the synthesis, characterization, and successful preclinical formulation of our lead compound, 5-bromo-6-methoxy-3'-azidothymidine-5'-(p-bromophenyl) methoxyalaninyl phosphate (WHI-07), which exhibits potent anti-HIV and sperm immobilizing activities. The anti-HIV activity of WHI-07 was tested by measuring viral p24 antigen production and reverse transcriptase activity as markers of viral replication in HIV-1 infected human peripheral blood mononuclear cells (PBMC). WHI-07 inhibited replication of HIV in a concentration-dependent fashion with nanomolar IC50 values. The effects of WHI-07 on human sperm motion kinematics were analysed by computer-assisted sperm analysis (CASA), and its effects on sperm membrane integrity were examined by confocal laser scanning microscopy (CLSM), and high-resolution low-voltage scanning electron microscopy (HR-LVSEM). WHI-07 caused cessation of sperm motility in a concentration- and time-dependent fashion. The in-vitro cytotoxicities of WHI-07 and nonoxynol-9 (N-9) were compared using normal human ectocervical and endocervical epithelial cells by the MTT cell viability assay. Unlike N-9, WHI-07 had no effect upon sperm plasma and acrosomal membrane integrity. N-9 was cytotoxic to normal human ectocervical and endocervical cells at spermicidal doses, whereas WHI-07 was selectively spermicidal. The in-vivo vaginal absorption and vaginal toxicity of 2% gel-microemulsion of WHI-07 was studied in the rabbit model. The sperm immobilizing activity of WHI-07 was 18-fold more potent than that of N-9. Over a 10 day period, there was no irritation or local toxicity to the vaginal epithelia or systemic absorption of WHI-07. Therefore, as a potent anti-HIV agent with spermicidal activity, and lack of mucosal toxicity, WHI-07 may have the clinical potential to become the active ingredient of a vaginal contraceptive for women who are at high risk for acquiring HIV by heterosexual vaginal transmission.  (+info)

Progesterone promotes the acrosome reaction in capacitated human spermatozoa as judged by flow cytometry and CD46 staining. (6/514)

The acrosome reaction is a necessary prerequisite for spermatozoa to acquire fertilizing ability. Several different moieties appear to promote the acrosome reaction through different pathways, including solubilized zona pellucidae, recombinant zona protein ZP3, follicular fluid, calcium ionophores, and mannosylated bovine serum albumin (BSA). Although many investigators have presented evidence that progesterone also promotes the acrosome reaction through the mediation of a non-genomic cell membrane receptor, this concept has been challenged. Other workers have suggested that progesterone does not promote an acrosome reaction in human spermatozoa, as judged by the detection of CD46, a complement regulatory protein present on the inner acrosome membrane, through flow cytometric analysis of large numbers of spermatozoa. Prior investigations were criticized by the limited numbers of spermatozoa enumerated visually, the use of non-specific staining techniques, and the failure to eliminate dead spermatozoa during the scoring of the acrosome reaction. We have repeated these experiments, using both a supravital dye to eliminate dead spermatozoa from flow cytometric analysis, and anti-CD46 monoclonal antibody to score acrosome-reacted spermatozoa. Care was taken to validate the adequacy of capacitation conditions, which were proven by the ability of spermatozoa to acrosome react in response to mannosylated BSA and to penetrate zona-free hamster eggs. Confocal microscopy was used to confirm that CD46 immunostaining was limited to the acrosomal region of the spermatozoon head. Our results indicate that progesterone does promote an acrosome reaction within capacitated spermatozoa.  (+info)

Characterization of human zona pellucida glycoproteins. (7/514)

The human egg may only be fertilized by one spermatozoon to prevent polyploidy. In most mammals, the primary block to polyspermy occurs at the zona pellucida (ZP). Little is known of the human ZP and the changes occurring following fertilization to prevent polyploidy. Using antibodies directed against synthetic peptides predicted from the human ZP2 and ZP3 cDNA, we identified ZP3 as a 53-60 kDa glycoprotein and ZP2 as a 90-110 kDa glycoprotein in prophase-I oocytes. Characterization of the ZP from metaphase II arrested eggs (inseminated-unfertilized and fertilized-uncleaved), shows no visible modification of ZP3, but demonstrates that ZP2 undergoes limited proteolysis in the amino terminal domain, to a 60-73 kDa species, denoted ZP2p, which remains linked to the proteolysed fragments by intramolecular disulphide bonds. A lack of ZP2 proteolytic activity in acrosomal supernatants is consistent with an oocyte origin for the protease. The ZP2-specific protease may be released during cortical granule exocytosis which occurs during meiotic maturation and following sperm-egg fusion as part of the block to polyspermy. Since mouse ZP2 acts as a secondary sperm receptor, it is possible that intact ZP2 binds a secondary egg binding protein, whereas cleaved ZP2 does not, suggesting a possible mechanism for the block to polyspermy.  (+info)

Identification of Rab3A GTPase as an acrosome-associated small GTP-binding protein in rat sperm. (8/514)

The acrosome reaction is a membrane fusion event that is prerequisite for sperm penetration through the zona pellucida. To elucidate the molecular mechanisms involved in membrane fusion, the expression and localization of Rab proteins, a subfamily of small GTPases that have been shown to play key roles in regulation of intracellular membrane traffic and exocytosis, were examined in rat testis and sperm. Reverse transcription polymerase chain reaction, immunoblot analysis, and immunofluorescence microscopy revealed that Rab3A protein, which is thought to be involved in regulation of exocytosis in neurons and endocrine cells, is associated with the sperm acrosome. The protein was undetectable in acrosome-free heads prepared by sucrose density gradient centrifugation. Immunogold electron microscopy performed on ultrathin cryosections provided further evidence that Rab3A protein is associated with the acrosomal membrane. Acrosome reaction assays revealed that synthetic peptide of the Rab3 effector domain inhibited acrosomal exocytosis triggered by calcium ionophore A23187 in a concentration-dependent fashion, suggesting that Rab3A acts as an inhibitory regulator in the acrosome reaction. In view of the putative role of Rab3A protein in membrane fusion systems, these results suggest that Rab3A could be involved in regulating the mammalian acrosome reaction by controlling the membrane fusion system in sperm.  (+info)

The acrosome reaction is a crucial event in the fertilization process of many species, including humans. It occurs when the sperm makes contact with and binds to the zona pellucida, the glycoprotein-rich extracellular matrix that surrounds the egg. This interaction triggers a series of molecular events leading to the exocytosis of the acrosome, a membrane-bound organelle located at the tip of the sperm head.

The acrosome contains hydrolytic enzymes that help the sperm to penetrate the zona pellucida and reach the egg's plasma membrane. During the acrosome reaction, the outer acrosomal membrane fuses with the sperm plasma membrane, releasing these enzymes and causing the release of the inner acrosomal membrane, which then reorganizes to form a structure called the acrosomal cap.

The acrosome reaction exposes new proteins on the sperm surface that can interact with the egg's plasma membrane, allowing for the fusion of the two membranes and the entry of the sperm into the egg. This event is essential for successful fertilization and subsequent embryonic development.

The acrosome is a specialized structure located on the anterior part of the sperm head in many species of animals, including humans. It contains enzymes that help the sperm penetrate the outer covering of the egg (zona pellucida) during fertilization. The acrosome reaction is the process by which the acrosome releases its enzymes, allowing the sperm to digest a path through the zona pellucida and reach the egg plasma membrane for fusion and fertilization.

The acrosome is formed during spermatogenesis, the process of sperm production in the testis, from the Golgi apparatus, a cellular organelle involved in protein trafficking and modification. The acrosome contains hydrolytic enzymes such as hyaluronidase, acrosin, and proteases that are activated during the acrosome reaction to facilitate sperm-egg fusion.

Abnormalities in acrosome formation or function can lead to infertility in males.

Spermatozoa are the male reproductive cells, or gametes, that are produced in the testes. They are microscopic, flagellated (tail-equipped) cells that are highly specialized for fertilization. A spermatozoon consists of a head, neck, and tail. The head contains the genetic material within the nucleus, covered by a cap-like structure called the acrosome which contains enzymes to help the sperm penetrate the female's egg (ovum). The long, thin tail propels the sperm forward through fluid, such as semen, enabling its journey towards the egg for fertilization.

Sperm capacitation is a complex process that occurs in the female reproductive tract and prepares sperm for fertilization. It involves a series of biochemical modifications to the sperm's membrane and motility, which enable it to undergo the acrosome reaction and penetrate the zona pellucida surrounding the egg.

The capacitation process typically takes several hours and requires the sperm to be exposed to specific factors in the female reproductive tract, including bicarbonate ions, calcium ions, and certain proteins. During capacitation, cholesterol is removed from the sperm's plasma membrane, which leads to an increase in membrane fluidity and the exposure of receptors that are necessary for binding to the egg.

Capacitation is a critical step in the fertilization process, as it ensures that only sperm that have undergone this process can successfully fertilize the egg. Abnormalities in sperm capacitation have been linked to infertility and other reproductive disorders.

Zona pellucida is a term used in the field of reproductive biology and it refers to the glycoprotein membrane that surrounds mammalian oocytes (immature egg cells). This membrane plays a crucial role in the fertilization process. It has receptors for sperm, and upon binding with the sperm, it undergoes changes that prevent other sperm from entering, a process known as the zona reaction. This membrane is also involved in the early development of the embryo.

Sperm-ovum interactions, also known as sperm-egg interactions, refer to the specific series of events that occur between a spermatozoon (sperm) and an oocyte (egg or ovum) during fertilization in sexual reproduction.

The process begins with the sperm's attachment to the zona pellucida, a glycoprotein layer surrounding the oocyte. This interaction is mediated by specific proteins on the surface of both the sperm and the zona pellucida. Following attachment, the sperm undergoes the acrosome reaction, during which enzymes are released from the sperm's head to help digest and penetrate the zona pellucida.

Once the sperm has successfully traversed the zona pellucida, it makes contact with the oocyte's plasma membrane, triggering the fusion of the sperm and egg membranes. This results in the release of the sperm's genetic material into the oocyte's cytoplasm and the initiation of a series of intracellular signaling events within the oocyte that ultimately lead to its completion of meiosis II and formation of a zygote, marking the beginning of embryonic development.

Proper sperm-ovum interactions are crucial for successful fertilization and subsequent embryonic development, and any disruptions in these processes can result in infertility or early pregnancy loss.

Sperm motility is the ability of sperm to move actively and effectively through the female reproductive tract towards the egg for fertilization. It is typically measured as the percentage of moving sperm in a sample, and their progressiveness or velocity. Normal human sperm motility is generally defined as forward progression of at least 25 micrometers per second, with at least 50% of sperm showing progressive motility. Reduced sperm motility, also known as asthenozoospermia, can negatively impact fertility and reproductive outcomes.

Acrosin is a proteolytic enzyme that is found in the acrosome, which is a cap-like structure located on the anterior part of the sperm head. This enzyme plays an essential role in the fertilization process by helping the sperm to penetrate the zona pellucida, which is the glycoprotein coat surrounding the egg.

Acrosin is released from the acrosome when the sperm encounters the zona pellucida, and it begins to digest the glycoproteins in the zona pellucida, creating a path for the sperm to reach and fuse with the egg's plasma membrane. This enzyme is synthesized and stored in the acrosome during spermatogenesis and is activated during the acrosome reaction, which is a critical event in fertilization.

Defects in acrosin function or regulation have been implicated in male infertility, making it an important area of research in reproductive biology.

A sperm head is the anterior (front) part of a spermatozoon, which contains the genetic material (DNA). It is covered by a protein layer called the acrosome, which plays a crucial role in fertilization. The sperm head is followed by the midpiece and the tail, which provide mobility to the sperm for its journey towards the egg.

Fertilization is the process by which a sperm cell (spermatozoon) penetrates and fuses with an egg cell (ovum), resulting in the formation of a zygote. This fusion of genetic material from both the male and female gametes initiates the development of a new organism. In human biology, fertilization typically occurs in the fallopian tube after sexual intercourse, when a single sperm out of millions is able to reach and penetrate the egg released from the ovary during ovulation. The successful fusion of these two gametes marks the beginning of pregnancy.

Egg proteins, also known as egg white proteins or ovalbumin, refer to the proteins found in egg whites. There are several different types of proteins found in egg whites, including:

1. Ovalbumin (54%): This is the major protein found in egg whites and is responsible for their white color. It has various functions such as providing nutrition, maintaining the structural integrity of the egg, and protecting the egg from bacteria.
2. Conalbumin (13%): Also known as ovotransferrin, this protein plays a role in the defense against microorganisms by binding to iron and making it unavailable for bacterial growth.
3. Ovomucoid (11%): This protein is resistant to digestion and helps protect the egg from being broken down by enzymes in the digestive tract of predators.
4. Lysozyme (3.5%): This protein has antibacterial properties and helps protect the egg from bacterial infection.
5. Globulins (4%): These are a group of simple proteins found in egg whites that have various functions such as providing nutrition, maintaining the structural integrity of the egg, and protecting the egg from bacteria.
6. Avidin (0.05%): This protein binds to biotin, a vitamin, making it unavailable for use by the body. However, cooking denatures avidin and makes the biotin available again.

Egg proteins are highly nutritious and contain all nine essential amino acids, making them a complete source of protein. They are also low in fat and cholesterol, making them a popular choice for those following a healthy diet.

Ionophores are compounds that have the ability to form complexes with ions and facilitate their transportation across biological membranes. They can be either organic or inorganic molecules, and they play important roles in various physiological processes, including ion homeostasis, signal transduction, and antibiotic activity. In medicine and research, ionophores are used as tools to study ion transport, modulate cellular functions, and as therapeutic agents, especially in the treatment of bacterial and fungal infections.

Calcimycin is a ionophore compound that is produced by the bacterium Streptomyces chartreusensis. It is also known as Calcineurin A inhibitor because it can bind to and inhibit the activity of calcineurin, a protein phosphatase. In medical research, calcimycin is often used to study calcium signaling in cells.
It has been also used in laboratory studies for its antiproliferative and pro-apoptotic effects on certain types of cancer cells. However, it is not approved for use as a drug in humans.

Peanut agglutinin (PNA) is a lectin, a type of carbohydrate-binding protein, found in peanuts. It is known to bind specifically to Galβ1-3GalNAc, a disaccharide present on glycoproteins and glycolipids of various cells. PNA has been used in research as a tool for identifying and isolating specific cell types, such as immature red blood cells (reticulocytes) and certain types of cancer cells, due to its affinity for these structures. However, it's important to note that peanut agglutinin may also have potential implications in the development of allergies to peanuts.

The vitelline membrane is a thin, transparent, flexible, and protective membrane that surrounds the yolk in bird, reptile, and some insect eggs. It provides nutrition and physical protection to the developing embryo during incubation. In medical terms, it is not directly relevant as it does not have a counterpart or equivalent structure in mammalian embryology.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

I'm happy to help! However, it seems there might be a bit of confusion here. "Sea urchins" is a common name that refers to a type of marine invertebrate animal, typically characterized by their round, spiny shells. They belong to the class Echinoidea within the phylum Echinodermata.

Medically speaking, there isn't a specific definition for "sea urchins." However, if you come into contact with sea urchins while swimming or diving and accidentally step on them, their spines can puncture your skin and potentially cause an infection. In this case, medical attention may be necessary to remove the embedded spines and treat any resulting infection.

If you were referring to a specific medical term related to sea urchins, could you please clarify? I'm here to help!

"Asterias" is a genus of starfish belonging to the family Asteriidae. The name "Asterias" itself does not have a specific medical definition, as it is a term used in the field of marine biology. However, some species of starfish in this genus may have potential medicinal or toxicological significance. For example, the venom of some asteriid starfish has been studied for its potential therapeutic applications, while others may contain toxins that can cause harm if ingested or come into contact with human skin.

It's worth noting that while some species of starfish may have medical relevance, the term "Asterias" does not have a direct medical definition and is not commonly used in medical contexts.

The epididymis is a tightly coiled tube located on the upper and posterior portion of the testicle that serves as the site for sperm maturation and storage. It is an essential component of the male reproductive system. The epididymis can be divided into three parts: the head (where newly produced sperm enter from the testicle), the body, and the tail (where mature sperm exit and are stored). Any abnormalities or inflammation in the epididymis may lead to discomfort, pain, or infertility.

Chlortetracycline is an antibiotic that belongs to the tetracycline class. It is primarily used to treat a variety of bacterial infections, including respiratory, urinary, and skin infections. Chlortetracycline works by inhibiting the bacteria's ability to produce proteins, which are essential for their survival and growth.

The medical definition of Chlortetracycline is as follows:

Chlortetracycline (CTC): A broad-spectrum antibiotic that is derived from the actinomycete Streptomyces aureofaciens. It is used to treat various bacterial infections, including respiratory, urinary, and skin infections. Chlortetracycline is a colorless crystalline powder that is soluble in water and alcohol. It has a molecular formula of C22H24ClN2O8 and a molecular weight of 476.93 g/mol.

Chlortetracycline is usually administered orally, but it can also be given intravenously or topically. The drug is absorbed well from the gastrointestinal tract and is widely distributed throughout the body. It has a half-life of about 8 hours and is excreted primarily in the urine.

Like other tetracyclines, Chlortetracycline can cause tooth discoloration and enamel hypoplasia in children under the age of 8. It can also cause photosensitivity, nausea, vomiting, and diarrhea. Prolonged use or high doses of Chlortetracycline can lead to bacterial resistance and may increase the risk of superinfection with fungi or other bacteria.

Chlortetracycline is no longer commonly used in human medicine due to the availability of newer antibiotics with fewer side effects. However, it is still used in veterinary medicine to treat infections in animals.

Fertilization in vitro, also known as in-vitro fertilization (IVF), is a medical procedure where an egg (oocyte) and sperm are combined in a laboratory dish to facilitate fertilization. The fertilized egg (embryo) is then transferred to a uterus with the hope of establishing a successful pregnancy. This procedure is often used when other assisted reproductive technologies have been unsuccessful or are not applicable, such as in cases of blocked fallopian tubes, severe male factor infertility, and unexplained infertility. The process involves ovarian stimulation, egg retrieval, fertilization, embryo culture, and embryo transfer. In some cases, additional techniques such as intracytoplasmic sperm injection (ICSI) or preimplantation genetic testing (PGT) may be used to increase the chances of success.

Spermatids are immature sperm cells that are produced during the process of spermatogenesis in the male testes. They are the product of the final stage of meiosis, where a diploid spermatocyte divides into four haploid spermatids. Each spermatid then undergoes a series of changes, including the development of a tail for motility and the condensation of its nucleus to form a head containing the genetic material. Once this process is complete, the spermatids are considered mature spermatozoa and are capable of fertilizing an egg.

Exocytosis is the process by which cells release molecules, such as hormones or neurotransmitters, to the extracellular space. This process involves the transport of these molecules inside vesicles (membrane-bound sacs) to the cell membrane, where they fuse and release their contents to the outside of the cell. It is a crucial mechanism for intercellular communication and the regulation of various physiological processes in the body.

Semen preservation is the process of collecting, liquefying, testing, and storing semen samples for future use in assisted reproductive technologies (ART) such as artificial insemination (AI), in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI). The semen sample is usually collected through masturbation, and then it is mixed with a cryoprotectant solution to prevent damage during the freezing and thawing process. After that, the sample is divided into straws or vials and frozen in liquid nitrogen tanks at temperatures below -196°C. Properly preserved semen can be stored for many years without significant loss of quality or fertility potential. Semen preservation is often recommended for men who are about to undergo medical treatments that may affect their sperm production or fertility, such as chemotherapy or radiation therapy, or for those who wish to postpone fatherhood for personal or medical reasons.

Pimozide is an antipsychotic medication that is primarily used to treat chronic tics and Tourette's disorder. It works by blocking the action of dopamine, a neurotransmitter in the brain that is involved in regulating movement and mood. By blocking dopamine receptors, pimozide helps to reduce the severity and frequency of tics and other symptoms associated with these conditions.

Pimozide may also be used off-label for the treatment of other conditions, such as severe behavioral problems in children with developmental disabilities. It is important to note that pimozide can have serious side effects, including cardiac arrhythmias and neurological symptoms, and should only be prescribed by a healthcare professional who is experienced in managing its use.

As with all medications, it's essential to follow the dosage instructions carefully and to report any unusual or concerning symptoms to your healthcare provider promptly.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Benzamidines are a group of organic compounds that contain a benzene ring linked to an amidine functional group. They are commonly used as antimicrobial agents, particularly in the treatment of various gram-negative bacterial infections. Benzamidines work by inhibiting the enzyme bacterial dehydrogenases, which are essential for the bacteria's survival.

Some examples of benzamidine derivatives include:

* Tempanamine hydrochloride (Tembaglanil): used to treat urinary tract infections caused by susceptible strains of Escherichia coli and Klebsiella pneumoniae.
* Chlorhexidine: a broad-spectrum antimicrobial agent used as a disinfectant and preservative in various medical and dental applications.
* Prothiobenzamide: an anti-inflammatory and analgesic drug used to treat gout and rheumatoid arthritis.

It is important to note that benzamidines have a narrow therapeutic index, which means that the difference between an effective dose and a toxic dose is small. Therefore, they should be used with caution and under the supervision of a healthcare professional.

Semen is a complex, whitish fluid that is released from the male reproductive system during ejaculation. It is produced by several glands, including the seminal vesicles, prostate gland, and bulbourethral glands. Semen contains several components, including sperm (the male reproductive cells), as well as various proteins, enzymes, vitamins, and minerals. Its primary function is to transport sperm through the female reproductive tract during sexual intercourse, providing nutrients and aiding in the protection of the sperm as they travel toward the egg for fertilization.

The "sperm tail" is also known as the flagellum, which is a whip-like structure that enables the sperm to move or swim through fluid. The human sperm tail is made up of nine microtubule doublets and a central pair of microtubules, which are surrounded by a mitochondrial sheath that provides energy for its movement. This complex structure allows the sperm to navigate through the female reproductive tract in order to reach and fertilize an egg.

Male infertility is a condition characterized by the inability to cause pregnancy in a fertile female. It is typically defined as the failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse.

The causes of male infertility can be varied and include issues with sperm production, such as low sperm count or poor sperm quality, problems with sperm delivery, such as obstructions in the reproductive tract, or hormonal imbalances that affect sperm production. Other factors that may contribute to male infertility include genetic disorders, environmental exposures, lifestyle choices, and certain medical conditions or treatments.

It is important to note that male infertility can often be treated or managed with medical interventions, such as medication, surgery, or assisted reproductive technologies (ART). A healthcare provider can help diagnose the underlying cause of male infertility and recommend appropriate treatment options.

Seminal plasma proteins are a group of proteins that are present in the seminal fluid, which is the liquid component of semen. These proteins originate primarily from the accessory sex glands, including the prostate, seminal vesicles, and bulbourethral glands, and play various roles in the maintenance of sperm function and fertility.

Some of the key functions of seminal plasma proteins include:

1. Nutrition: Seminal plasma proteins provide energy sources and essential nutrients to support sperm survival and motility during their journey through the female reproductive tract.
2. Protection: These proteins help protect sperm from oxidative stress, immune attack, and other environmental factors that could negatively impact sperm function or viability.
3. Lubrication: Seminal plasma proteins contribute to the formation of a fluid medium that facilitates the ejaculation and transport of sperm through the female reproductive tract.
4. Coagulation and liquefaction: Some seminal plasma proteins are involved in the initial coagulation and subsequent liquefaction of semen, which helps ensure proper sperm release and distribution during ejaculation.
5. Interaction with female reproductive system: Seminal plasma proteins can interact with components of the female reproductive tract to modulate immune responses, promote implantation, and support early embryonic development.

Examples of seminal plasma proteins include prostate-specific antigen (PSA), prostate-specific acid phosphatase (PSAP), and semenogelins. Abnormal levels or dysfunctions in these proteins have been associated with various reproductive disorders, such as infertility, prostatitis, and prostate cancer.

Rab3A GTP-binding protein is a small GTPase, which is a type of molecular switch that regulates various cellular processes, including vesicle trafficking in the cell. Specifically, Rab3A is involved in regulating the release of neurotransmitters from neurons. It plays a role in the docking and fusion of synaptic vesicles with the presynaptic membrane during neurotransmission. When GTP is bound to Rab3A, it is in its active state and can participate in these processes. When GDP is bound, it is in its inactive state. The activity of Rab3A is regulated by various factors, including GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs), which help to control the cycling of GTP and GDP binding and unbinding.

The testis, also known as the testicle, is a male reproductive organ that is part of the endocrine system. It is located in the scrotum, outside of the abdominal cavity. The main function of the testis is to produce sperm and testosterone, the primary male sex hormone.

The testis is composed of many tiny tubules called seminiferous tubules, where sperm are produced. These tubules are surrounded by a network of blood vessels, nerves, and supportive tissues. The sperm then travel through a series of ducts to the epididymis, where they mature and become capable of fertilization.

Testosterone is produced in the Leydig cells, which are located in the interstitial tissue between the seminiferous tubules. Testosterone plays a crucial role in the development and maintenance of male secondary sexual characteristics, such as facial hair, deep voice, and muscle mass. It also supports sperm production and sexual function.

Abnormalities in testicular function can lead to infertility, hormonal imbalances, and other health problems. Regular self-examinations and medical check-ups are recommended for early detection and treatment of any potential issues.

Calcium ionophores are chemical compounds that increase the permeability of cell membranes to calcium ions. They function by forming a complex with calcium and facilitating its transport across the lipid bilayer of the cell membrane, thereby raising the intracellular concentration of calcium ions (Ca²+).

These ionophores are often used in research and medical settings to study calcium signaling pathways and calcium-mediated cellular processes. They have been utilized in various experimental models to investigate cell proliferation, differentiation, secretion, and muscle contraction. In clinical contexts, calcium ionophores like A23187 are sometimes employed in the diagnosis of certain disorders affecting immune cells, such as detecting T-lymphocyte function in patients with suspected immunodeficiency.

However, it is essential to note that calcium ionophores can induce cytotoxicity at higher concentrations and may trigger uncontrolled calcium signaling, which could lead to cell damage or death. Therefore, their usage should be carefully controlled and monitored in both research and clinical applications.

'Bufo arenarum' is the scientific name for a species of toad that is native to Argentina. This toad, also known as the Argentine Toad or the Sand Toad, produces a toxic secretion from its skin as a defense against predators. The toxicity of this secretion can be harmful or even fatal if ingested or absorbed through the mucous membranes, making handling this toad with care important.

The medical definition of 'Bufo arenarum' would typically refer to the physical characteristics and behaviors of this species, as well as any potential medical implications of its toxic secretions. It is worth noting that some people have used the dried secretion of this toad, known as "toad licks" or "toad venom," as a recreational drug, despite the significant health risks associated with its use. This practice is strongly discouraged due to the potential for serious harm or even death.

Spermatogenesis is the process by which sperm cells, or spermatozoa, are produced in male organisms. It occurs in the seminiferous tubules of the testes and involves several stages:

1. Spermatocytogenesis: This is the initial stage where diploid spermatogonial stem cells divide mitotically to produce more spermatogonia, some of which will differentiate into primary spermatocytes.
2. Meiosis: The primary spermatocytes undergo meiotic division to form haploid secondary spermatocytes, which then divide again to form haploid spermatids. This process results in the reduction of chromosome number from 46 (diploid) to 23 (haploid).
3. Spermiogenesis: The spermatids differentiate into spermatozoa, undergoing morphological changes such as the formation of a head and tail. During this stage, most of the cytoplasm is discarded, resulting in highly compacted and streamlined sperm cells.
4. Spermation: The final stage where mature sperm are released from the seminiferous tubules into the epididymis for further maturation and storage.

The entire process takes approximately 72-74 days in humans, with continuous production throughout adulthood.

Sperm maturation is the process by which spermatids, immature sperm cells produced in meiosis, transform into fully developed spermatozoa capable of fertilization. This complex process occurs in the seminiferous tubules of the testes and includes several stages:

1. **Golfi formation:** The first step involves the spermatids reorganizing their cytoplasm and forming a cap-like structure called the acrosome, which contains enzymes that help the sperm penetrate the egg's outer layers during fertilization.
2. **Flagellum development:** The spermatid also develops a tail (flagellum), enabling it to move independently. This is achieved through the assembly of microtubules and other associated proteins.
3. **Nuclear condensation and elongation:** The sperm's DNA undergoes significant compaction, making the nucleus smaller and more compact. Concurrently, the nucleus elongates and aligns with the flagellum.
4. **Mitochondrial positioning:** Mitochondria, which provide energy for sperm motility, migrate to the midpiece of the sperm, close to the base of the flagellum.
5. **Chromatin packaging:** Histones, proteins that help package DNA in non-sperm cells, are replaced by transition proteins and then protamines, which further compact and protect the sperm's DNA.
6. **Sperm release (spermiation):** The mature sperm is finally released from the supporting Sertoli cells into the lumen of the seminiferous tubule, where it mixes with fluid secreted by the testicular tissue to form seminal plasma.

This entire process takes approximately 64 days in humans.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

CD46, also known as membrane cofactor protein (MCP), is a regulatory protein that plays a role in the immune system and helps to protect cells from complement activation. It is found on the surface of many different types of cells in the body, including cells of the immune system such as T cells and B cells, as well as cells of various other tissues such as epithelial cells and endothelial cells.

As an antigen, CD46 is a molecule that can be recognized by the immune system and stimulate an immune response. It is a type I transmembrane protein that consists of four distinct domains: two short cytoplasmic domains, a transmembrane domain, and a large extracellular domain. The extracellular domain contains several binding sites for complement proteins, which helps to regulate the activation of the complement system and prevent it from damaging host cells.

CD46 has been shown to play a role in protecting cells from complement-mediated damage, modulating immune responses, and promoting the survival and proliferation of certain types of immune cells. It is also thought to be involved in the development of some autoimmune diseases and may be a target for immunotherapy in the treatment of cancer.

Bisbenzimidazoles are a class of chemical compounds consisting of two benzimidazole rings joined by a bridge. They are often used in biochemistry and molecular biology as fluorescent dyes for the staining and detection of DNA in various applications, such as DNA sequencing, Southern blotting, and fluorescence in situ hybridization (FISH).

One of the most commonly used bisbenzimidazoles is 4',6-diamidino-2-phenylindole (DAPI), which binds to the minor groove of DNA and emits blue fluorescence upon excitation. This property makes DAPI a useful tool for visualizing nuclei in cells and tissues, as well as for detecting and quantifying DNA in various experimental settings.

It's important to note that while bisbenzimidazoles have many uses in scientific research, they are not typically used as therapeutic agents in medicine.

Progesterone is a steroid hormone that is primarily produced in the ovaries during the menstrual cycle and in pregnancy. It plays an essential role in preparing the uterus for implantation of a fertilized egg and maintaining the early stages of pregnancy. Progesterone works to thicken the lining of the uterus, creating a nurturing environment for the developing embryo.

During the menstrual cycle, progesterone is produced by the corpus luteum, a temporary structure formed in the ovary after an egg has been released from a follicle during ovulation. If pregnancy does not occur, the levels of progesterone will decrease, leading to the shedding of the uterine lining and menstruation.

In addition to its reproductive functions, progesterone also has various other effects on the body, such as helping to regulate the immune system, supporting bone health, and potentially influencing mood and cognition. Progesterone can be administered medically in the form of oral pills, intramuscular injections, or vaginal suppositories for various purposes, including hormone replacement therapy, contraception, and managing certain gynecological conditions.

Lysophosphatidylcholines (LPCs) are a type of glycerophospholipids, which are major components of cell membranes. They are formed by the hydrolysis of phosphatidylcholines, another type of glycerophospholipids, catalyzed by the enzyme phospholipase A2. LPCs contain a single fatty acid chain attached to a glycerol backbone and a choline headgroup.

In medical terms, LPCs have been implicated in various physiological and pathological processes, such as cell signaling, membrane remodeling, and inflammation. Elevated levels of LPCs have been found in several diseases, including cardiovascular disease, neurodegenerative disorders, and cancer. They can also serve as biomarkers for the diagnosis and prognosis of these conditions.

Nigericin is not typically considered to have a "medical definition" as it is not a medication or therapeutic agent used in human medicine. However, it is a chemical compound that has been studied in laboratory research for its potential effects on various biological processes.

Nigericin is a polyether antibiotic produced by the bacterium Streptomyces hygroscopicus. It functions as an ionophore, which is a type of molecule that can transport ions across cell membranes. Specifically, nigericin can transport potassium (K+) and hydrogen (H+) ions across membranes, which can affect the balance of these ions inside and outside of cells.

In laboratory research, nigericin has been used to study various cellular processes, including the regulation of intracellular pH, mitochondrial function, and inflammation. However, it is not used as a therapeutic agent in clinical medicine due to its potential toxicity and narrow therapeutic window.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

"Mesocricetus" is a genus of rodents, more commonly known as hamsters. It includes several species of hamsters that are native to various parts of Europe and Asia. The best-known member of this genus is the Syrian hamster, also known as the golden hamster or Mesocricetus auratus, which is a popular pet due to its small size and relatively easy care. These hamsters are burrowing animals and are typically solitary in the wild.

I believe there might be a slight confusion in your question. Sulfuric acid is not a medical term, but instead a chemical compound with the formula H2SO4. It's one of the most important industrial chemicals, being a strong mineral acid with numerous applications.

If you are asking for a definition related to human health or medicine, I can tell you that sulfuric acid has no physiological role in humans. Exposure to sulfuric acid can cause irritation and burns to the skin, eyes, and respiratory tract. Prolonged exposure may lead to more severe health issues. However, it is not a term typically used in medical diagnoses or treatments.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

I believe you may be mistakenly using the term "starfish" to refer to a medical condition. If so, the correct term is likely " asterixis," which is a medical sign characterized by rapid, rhythmic flapping or tremulous movements of the hands when they are extended and the wrist is dorsiflexed (held with the back of the hand facing upwards). This is often seen in people with certain neurological conditions such as liver failure or certain types of poisoning.

However, if you are indeed referring to the marine animal commonly known as a "starfish," there isn't a specific medical definition for it. Starfish, also known as sea stars, are marine animals belonging to the class Asteroidea in the phylum Echinodermata. They have a distinctive shape with five or more arms radiating from a central disc, and they move slowly along the ocean floor using their tube feet. Some species of starfish have the ability to regenerate lost body parts, including entire limbs or even their central disc.

The cervix is the lower, narrow part of the uterus that opens into the vagina. Cervical mucus is a clear or cloudy secretion produced by glands in the cervix. The amount and consistency of cervical mucus changes throughout a woman's menstrual cycle, influenced by hormonal fluctuations.

During the fertile window (approximately mid-cycle), estrogen levels rise, causing the cervical mucus to become more abundant, clear, and stretchy (often described as resembling raw egg whites). This "fertile" mucus facilitates the movement of sperm through the cervix and into the uterus, increasing the chances of fertilization.

As the menstrual cycle progresses and progesterone levels rise after ovulation, cervical mucus becomes thicker, cloudier, and less abundant, making it more difficult for sperm to penetrate. This change in cervical mucus helps prevent additional sperm from entering and fertilizing an already-fertilized egg.

Changes in cervical mucus can be used as a method of natural family planning or fertility awareness, with women checking their cervical mucus daily to identify their most fertile days. However, this method should be combined with other tracking methods for increased accuracy and reliability.

Fluorescein-5-isothiocyanate (FITC) is not a medical term per se, but a chemical compound commonly used in biomedical research and clinical diagnostics. Therefore, I will provide a general definition of this term:

Fluorescein-5-isothiocyanate (FITC) is a fluorescent dye with an absorption maximum at approximately 492-495 nm and an emission maximum at around 518-525 nm. It is widely used as a labeling reagent for various biological molecules, such as antibodies, proteins, and nucleic acids, to study their structure, function, and interactions in techniques like flow cytometry, immunofluorescence microscopy, and western blotting. The isothiocyanate group (-N=C=S) in the FITC molecule reacts with primary amines (-NH2) present in biological molecules to form a stable thiourea bond, enabling specific labeling of target molecules for detection and analysis.

The sperm midpiece is a part of the sperm flagellum, which is the tail-like structure that enables sperm motility. The midpiece is located between the sperm head and the principal piece, which is the longest part of the flagellum.

The midpiece is characterized by the presence of mitochondria, which provide the energy required for sperm movement through a process called oxidative phosphorylation. The midpiece also contains a ring of nine outer dense fibers that surround the axoneme, which is the core structure of the flagellum. These fibers help to maintain the structural integrity and flexibility of the sperm tail.

Damage or abnormalities in the sperm midpiece can affect sperm motility and fertility.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Fertility is the natural ability to conceive or to cause conception of offspring. In humans, it is the capacity of a woman and a man to reproduce through sexual reproduction. For women, fertility usually takes place during their reproductive years, which is from adolescence until menopause. A woman's fertility depends on various factors including her age, overall health, and the health of her reproductive system.

For men, fertility can be affected by a variety of factors such as age, genetics, general health, sexual function, and environmental factors that may affect sperm production or quality. Factors that can negatively impact male fertility include exposure to certain chemicals, radiation, smoking, alcohol consumption, drug use, and sexually transmitted infections (STIs).

Infertility is a common medical condition affecting about 10-15% of couples trying to conceive. Infertility can be primary or secondary. Primary infertility refers to the inability to conceive after one year of unprotected sexual intercourse, while secondary infertility refers to the inability to conceive following a previous pregnancy.

Infertility can be treated with various medical and surgical interventions depending on the underlying cause. These may include medications to stimulate ovulation, intrauterine insemination (IUI), in vitro fertilization (IVF), or surgery to correct anatomical abnormalities.

Sperm agglutination is the clumping or sticking together of sperm cells, which can be caused by the presence of antibodies or other substances in semen. In some cases, sperm agglutination may occur due to an immune response in which the body produces antibodies that attack and bind to sperm cells, leading to their clumping together. This can interfere with the sperm's ability to move and fertilize an egg.

Sperm agglutination can be detected through a semen analysis test, which involves examining a sample of semen under a microscope. If sperm agglutination is present, it may indicate an underlying medical condition or issue that requires further evaluation and treatment. In some cases, sperm agglutination may be treated with medications to reduce the production of antibodies or other substances that are causing the problem.

Cryopreservation is a medical procedure that involves the preservation of cells, tissues, or organs by cooling them to very low temperatures, typically below -150°C. This is usually achieved using liquid nitrogen. The low temperature slows down or stops biological activity, including chemical reactions and cellular metabolism, which helps to prevent damage and decay.

The cells, tissues, or organs that are being cryopreserved must be treated with a cryoprotectant solution before cooling to prevent the formation of ice crystals, which can cause significant damage. Once cooled, the samples are stored in specialized containers or tanks until they are needed for use.

Cryopreservation is commonly used in assisted reproductive technologies, such as the preservation of sperm, eggs, and embryos for fertility treatments. It is also used in research, including the storage of cell lines and stem cells, and in clinical settings, such as the preservation of skin grafts and corneas for transplantation.

Membrane glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. They are integral components of biological membranes, spanning the lipid bilayer and playing crucial roles in various cellular processes.

The glycosylation of these proteins occurs in the endoplasmic reticulum (ER) and Golgi apparatus during protein folding and trafficking. The attached glycans can vary in structure, length, and composition, which contributes to the diversity of membrane glycoproteins.

Membrane glycoproteins can be classified into two main types based on their orientation within the lipid bilayer:

1. Type I (N-linked): These glycoproteins have a single transmembrane domain and an extracellular N-terminus, where the oligosaccharides are predominantly attached via asparagine residues (Asn-X-Ser/Thr sequon).
2. Type II (C-linked): These glycoproteins possess two transmembrane domains and an intracellular C-terminus, with the oligosaccharides linked to tryptophan residues via a mannose moiety.

Membrane glycoproteins are involved in various cellular functions, such as:

* Cell adhesion and recognition
* Receptor-mediated signal transduction
* Enzymatic catalysis
* Transport of molecules across membranes
* Cell-cell communication
* Immunological responses

Some examples of membrane glycoproteins include cell surface receptors (e.g., growth factor receptors, cytokine receptors), adhesion molecules (e.g., integrins, cadherins), and transporters (e.g., ion channels, ABC transporters).

The Fallopian tubes, also known as uterine tubes or oviducts, are a pair of slender tubular structures in the female reproductive system. They play a crucial role in human reproduction by providing a passageway for the egg (ovum) from the ovary to the uterus (womb).

Each Fallopian tube is typically around 7.6 to 10 centimeters long and consists of four parts: the interstitial part, the isthmus, the ampulla, and the infundibulum. The fimbriated end of the infundibulum, which resembles a fringe or frill, surrounds and captures the released egg from the ovary during ovulation.

Fertilization usually occurs in the ampulla when sperm meets the egg after sexual intercourse. Once fertilized, the zygote (fertilized egg) travels through the Fallopian tube toward the uterus for implantation and further development. The cilia lining the inner surface of the Fallopian tubes help propel the egg and the zygote along their journey.

In some cases, abnormalities or blockages in the Fallopian tubes can lead to infertility or ectopic pregnancies, which are pregnancies that develop outside the uterus, typically within the Fallopian tube itself.

'Sus scrofa' is the scientific name for the wild boar, a species of suid that is native to much of Eurasia and North Africa. It is not a medical term or concept. If you have any questions related to medical terminology or health-related topics, I would be happy to help with those instead!

Semen analysis is a laboratory test that evaluates various characteristics of semen, the fluid that is released during ejaculation. These characteristics include:

1. Volume: The amount of semen produced in one ejaculation.
2. Liquefaction time: The time it takes for the semen to change from a gel-like consistency to a liquid state.
3. pH: The acidity or alkalinity of the semen.
4. Sperm concentration: The number of sperm present in each milliliter of semen.
5. Total sperm count: The total number of sperm in the entire ejaculate.
6. Motility: The percentage of sperm that are moving and their forward progression.
7. Morphology: The shape and size of the sperm.
8. Vitality: The percentage of live sperm in the sample.
9. White blood cell count: The presence of white blood cells, which can indicate an infection.

Semen analysis is often used to help diagnose male infertility, as well as to monitor the effectiveness of treatments for infertility. It may also be used to detect abnormalities in the reproductive system or to evaluate the effects of certain medications on sperm production and quality.

I'm sorry for any confusion, but the term "shrews" is not a medical term. It is a common name used in zoology to refer to small mammals that are part of the family Soricidae and the suborder Soricomorpha. Shrews are insectivores, distantly related to moles and hedgehogs. If you have any questions about medical terminology or concepts, I would be happy to help!

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

Follicular fluid is the fluid that accumulates within the follicle (a small sac or cyst) in the ovary where an egg matures. This fluid contains various chemicals, hormones, and proteins that support the growth and development of the egg cell. It also contains metabolic waste products and other substances from the granulosa cells (the cells that surround the egg cell within the follicle). Follicular fluid is often analyzed in fertility treatments and studies as it can provide valuable information about the health and viability of the egg cell.

Sperm count, also known as sperm concentration, is the number of sperm present in a given volume of semen. The World Health Organization (WHO) previously defined a normal sperm count as at least 20 million sperm per milliliter of semen. However, more recent studies suggest that fertility may be affected even when sperm counts are slightly lower than this threshold. It's important to note that sperm count is just one factor among many that can influence male fertility. Other factors, such as sperm motility (the ability of sperm to move properly) and morphology (the shape of the sperm), also play crucial roles in successful conception.

In the context of medicine, the term "elements" generally refers to the basic constituents or parts that make up a whole. These can include chemical elements, such as carbon, hydrogen, and oxygen, which are the building blocks of biological molecules like proteins, lipids, and carbohydrates.

However, "elements" can also refer more broadly to the fundamental components of a system or process. For example, in traditional humorism, one of the ancient medical systems, the four "elements" were considered to be black bile, yellow bile, phlegm, and blood, which were believed to correspond to different temperaments and bodily functions.

In modern medicine, the term is less commonly used, but it may still refer to the basic components of a biological or chemical system, such as the elements of a chemical reaction or the building blocks of a cell.

'Murinae' is not a medical term. It is a taxonomic classification used in biology, specifically for a subfamily of rodents that includes mice, rats, and several related species. The term 'Murinae' comes from the family Muridae, which is the largest family of mammals, containing over 700 species.

The misconception might arise because medical professionals sometimes use common names for various animals or organisms in their diagnoses, treatments, or research. However, it is essential to clarify that 'Murinae' is a scientific classification and not a medical term.

Monensin is a type of antibiotic known as a polyether ionophore, which is used primarily in the veterinary field for the prevention and treatment of coccidiosis, a parasitic disease caused by protozoa in animals. It works by selectively increasing the permeability of cell membranes to sodium ions, leading to disruption of the ion balance within the cells of the parasite and ultimately causing its death.

In addition to its use as an animal antibiotic, monensin has also been studied for its potential effects on human health, including its ability to lower cholesterol levels and improve insulin sensitivity in type 2 diabetes. However, it is not currently approved for use in humans due to concerns about toxicity and potential side effects.

Ejaculation is the discharge of semen, typically accompanied by orgasm, during sexual activity. It occurs when the male reproductive system releases semen from the penis. This process is usually brought on by sexual arousal and stimulation, which cause the sperm-carrying vas deferens to contract and push the semen into the urethra, from where it is expelled through the tip of the penis.

There are two types of ejaculation:

1. **Reflex ejaculation**: This occurs when there is a high level of sexual excitement or stimulation, leading to an involuntary and automatic response.
2. **Premature ejaculation**: This refers to the condition where ejaculation happens too quickly, often before or shortly after penetration, causing distress and affecting sexual satisfaction for both partners.

It is essential to understand that a healthy male can experience variations in the timing of ejaculation throughout their life, influenced by factors such as age, stress levels, and overall health. If you have concerns about your ejaculation patterns or any related issues, it is recommended to consult a healthcare professional for advice and treatment options.

Fucose is a type of sugar molecule that is often found in complex carbohydrates known as glycans, which are attached to many proteins and lipids in the body. It is a hexose sugar, meaning it contains six carbon atoms, and is a type of L-sugar, which means that it rotates plane-polarized light in a counterclockwise direction.

Fucose is often found at the ends of glycan chains and plays important roles in various biological processes, including cell recognition, signaling, and interaction. It is also a component of some blood group antigens and is involved in the development and function of the immune system. Abnormalities in fucosylation (the addition of fucose to glycans) have been implicated in various diseases, including cancer, inflammation, and neurological disorders.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Glycoconjugates are a type of complex molecule that form when a carbohydrate (sugar) becomes chemically linked to a protein or lipid (fat) molecule. This linkage, known as a glycosidic bond, results in the formation of a new molecule that combines the properties and functions of both the carbohydrate and the protein or lipid component.

Glycoconjugates can be classified into several categories based on the type of linkage and the nature of the components involved. For example, glycoproteins are glycoconjugates that consist of a protein backbone with one or more carbohydrate chains attached to it. Similarly, glycolipids are molecules that contain a lipid anchor linked to one or more carbohydrate residues.

Glycoconjugates play important roles in various biological processes, including cell recognition, signaling, and communication. They are also involved in the immune response, inflammation, and the development of certain diseases such as cancer and infectious disorders. As a result, understanding the structure and function of glycoconjugates is an active area of research in biochemistry, cell biology, and medical science.

The Fluorescent Antibody Technique (FAT), Indirect is a type of immunofluorescence assay used to detect the presence of specific antigens in a sample. In this method, the sample is first incubated with a primary antibody that binds to the target antigen. After washing to remove unbound primary antibodies, a secondary fluorescently labeled antibody is added, which recognizes and binds to the primary antibody. This indirect labeling approach allows for amplification of the signal, making it more sensitive than direct methods. The sample is then examined under a fluorescence microscope to visualize the location and amount of antigen based on the emitted light from the fluorescent secondary antibody. It's commonly used in diagnostic laboratories for detection of various bacteria, viruses, and other antigens in clinical specimens.

Immunoelectron microscopy (IEM) is a specialized type of electron microscopy that combines the principles of immunochemistry and electron microscopy to detect and localize specific antigens within cells or tissues at the ultrastructural level. This technique allows for the visualization and identification of specific proteins, viruses, or other antigenic structures with a high degree of resolution and specificity.

In IEM, samples are first fixed, embedded, and sectioned to prepare them for electron microscopy. The sections are then treated with specific antibodies that have been labeled with electron-dense markers, such as gold particles or ferritin. These labeled antibodies bind to the target antigens in the sample, allowing for their visualization under an electron microscope.

There are several different methods of IEM, including pre-embedding and post-embedding techniques. Pre-embedding involves labeling the antigens before embedding the sample in resin, while post-embedding involves labeling the antigens after embedding. Post-embedding techniques are generally more commonly used because they allow for better preservation of ultrastructure and higher resolution.

IEM is a valuable tool in many areas of research, including virology, bacteriology, immunology, and cell biology. It can be used to study the structure and function of viruses, bacteria, and other microorganisms, as well as the distribution and localization of specific proteins and antigens within cells and tissues.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

Pentoxifylline is a medication that belongs to a class of drugs known as xanthines. Medically, it is defined as a methylxanthine derivative that acts as a vasodilator and improves blood flow by reducing the viscosity of blood. It is used in the treatment of intermittent claudication (pain in the legs due to poor circulation) and may also be used for other conditions that benefit from improved blood flow, such as preventing kidney damage in people with diabetes.

Pentoxifylline works by increasing the flexibility of red blood cells, allowing them to move more easily through narrowed blood vessels, improving oxygen supply to tissues and organs. It also has anti-inflammatory effects that may contribute to its therapeutic benefits.

Common side effects of pentoxifylline include gastrointestinal symptoms like nausea, vomiting, and diarrhea. Less commonly, it can cause dizziness, headache, or skin rashes. Rare but serious side effects include decreased blood pressure, irregular heartbeat, and liver damage. It is essential to follow the prescribing physician's instructions carefully when taking pentoxifylline and report any unusual symptoms promptly.

Plant lectins are proteins or glycoproteins that are abundantly found in various plant parts such as seeds, leaves, stems, and roots. They have the ability to bind specifically to carbohydrate structures present on cell membranes, known as glycoconjugates. This binding property of lectins is reversible and non-catalytic, meaning it does not involve any enzymatic activity.

Lectins play several roles in plants, including defense against predators, pathogens, and herbivores. They can agglutinate red blood cells, stimulate the immune system, and have been implicated in various biological processes such as cell growth, differentiation, and apoptosis (programmed cell death). Some lectins also exhibit mitogenic activity, which means they can stimulate the proliferation of certain types of cells.

In the medical field, plant lectins have gained attention due to their potential therapeutic applications. For instance, some lectins have been shown to possess anti-cancer properties and are being investigated as potential cancer treatments. However, it is important to note that some lectins can be toxic or allergenic to humans and animals, so they must be used with caution.

ICR (Institute of Cancer Research) is a strain of albino Swiss mice that are widely used in scientific research. They are an outbred strain, which means that they have been bred to maintain maximum genetic heterogeneity. However, it is also possible to find inbred strains of ICR mice, which are genetically identical individuals produced by many generations of brother-sister mating.

Inbred ICR mice are a specific type of ICR mouse that has been inbred for at least 20 generations. This means that they have a high degree of genetic uniformity and are essentially genetically identical to one another. Inbred strains of mice are often used in research because their genetic consistency makes them more reliable models for studying biological phenomena and testing new therapies or treatments.

It is important to note that while inbred ICR mice may be useful for certain types of research, they do not necessarily represent the genetic diversity found in human populations. Therefore, it is important to consider the limitations of using any animal model when interpreting research findings and applying them to human health.

Sperm transport refers to the series of events that occur from the production of sperm in the testes to their release into the female reproductive tract during sexual intercourse. This process involves several stages:

1. Spermatogenesis: The production of sperm cells (spermatozoa) takes place in the seminiferous tubules within the testes.
2. Maturation: The newly produced sperm are immature and incapable of fertilization. They undergo a maturation process as they move through the epididymis, where they acquire motility and the ability to fertilize an egg.
3. Ejaculation: During sexual arousal, sperm are mixed with seminal fluid produced by the seminal vesicles, prostate gland, and bulbourethral glands to form semen. This mixture is propelled through the urethra during orgasm (ejaculation) and released from the penis into the female reproductive tract.
4. Transport within the female reproductive tract: Once inside the female reproductive tract, sperm must travel through the cervix, uterus, and fallopian tubes to reach the site of fertilization, the ampullary-isthmic junction of the fallopian tube. This journey can take several hours to a few days.
5. Capacitation: During their transport within the female reproductive tract, sperm undergo further changes called capacitation, which prepares them for fertilization by increasing their motility and making them more responsive to the egg's chemical signals.
6. Acrosome reaction: The final step in sperm transport is the acrosome reaction, where the sperm releases enzymes from the acrosome (a cap-like structure on the head of the sperm) to penetrate and fertilize the egg.

Membrane fusion is a fundamental biological process that involves the merging of two initially separate lipid bilayers, such as those surrounding cells or organelles, to form a single continuous membrane. This process plays a crucial role in various physiological events including neurotransmitter release, hormone secretion, fertilization, viral infection, and intracellular trafficking of proteins and lipids. Membrane fusion is tightly regulated and requires the participation of specific proteins called SNAREs (Soluble NSF Attachment Protein REceptors) and other accessory factors that facilitate the recognition, approximation, and merger of the membranes. The energy required to overcome the repulsive forces between the negatively charged lipid headgroups is provided by these proteins, which undergo conformational changes during the fusion process. Membrane fusion is a highly specific and coordinated event, ensuring that the correct membranes fuse at the right time and place within the cell.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.

The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.

Phospholipase C delta (PLCδ) is an enzyme that plays a crucial role in intracellular signaling pathways. It belongs to the phospholipase C family, which are enzymes that cleave phospholipids into secondary messengers.

Specifically, PLCδ is activated by G protein-coupled receptors and breaks down a specific type of phospholipid called PIP2 (phosphatidylinositol 4,5-bisphosphate) into two second messengers: diacylglycerol (DAG) and inositol trisphosphate (IP3). These second messengers then go on to activate various downstream signaling pathways, which can lead to changes in gene expression, cell growth, differentiation, and other cellular responses.

There are four isoforms of PLCδ (PLCδ1, PLCδ2, PLCδ3, and PLCδ4) that are encoded by separate genes but share a similar structure and function. Mutations in the genes encoding PLCδ have been associated with various diseases, including cancer and neurological disorders.

Aminacrine is a type of medication known as an antineoplastic agent or chemotherapeutic drug. It is primarily used in the treatment of certain types of cancer. Aminacrine works by interfering with the DNA replication process within cancer cells, which helps to inhibit the growth and proliferation of these cells.

The chemical name for aminacrine is 9-aminoacridine hydrochloride monohydrate. It has a yellowish crystalline appearance and is typically administered intravenously in a hospital setting. Common side effects of aminacrine include nausea, vomiting, diarrhea, mouth sores, and hair loss. More serious side effects can include heart rhythm abnormalities, seizures, and lung or kidney damage.

It's important to note that the use of aminacrine is typically reserved for cases where other cancer treatments have not been effective, due to its potential for serious side effects. As with all medications, it should be used under the close supervision of a healthcare professional.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

Fluorescent dyes are substances that emit light upon excitation by absorbing light of a shorter wavelength. In a medical context, these dyes are often used in various diagnostic tests and procedures to highlight or mark certain structures or substances within the body. For example, fluorescent dyes may be used in imaging techniques such as fluorescence microscopy or fluorescence angiography to help visualize cells, tissues, or blood vessels. These dyes can also be used in flow cytometry to identify and sort specific types of cells. The choice of fluorescent dye depends on the specific application and the desired properties, such as excitation and emission spectra, quantum yield, and photostability.

Calcium channels are specialized proteins that span the membrane of cells and allow calcium ions (Ca²+) to flow in and out of the cell. They are crucial for many physiological processes, including muscle contraction, neurotransmitter release, hormone secretion, and gene expression.

There are several types of calcium channels, classified based on their biophysical and pharmacological properties. The most well-known are:

1. Voltage-gated calcium channels (VGCCs): These channels are activated by changes in the membrane potential. They are further divided into several subtypes, including L-type, P/Q-type, N-type, R-type, and T-type. VGCCs play a critical role in excitation-contraction coupling in muscle cells and neurotransmitter release in neurons.
2. Receptor-operated calcium channels (ROCCs): These channels are activated by the binding of an extracellular ligand, such as a hormone or neurotransmitter, to a specific receptor on the cell surface. ROCCs are involved in various physiological processes, including smooth muscle contraction and platelet activation.
3. Store-operated calcium channels (SOCCs): These channels are activated by the depletion of intracellular calcium stores, such as those found in the endoplasmic reticulum. SOCCs play a critical role in maintaining calcium homeostasis and signaling within cells.

Dysregulation of calcium channel function has been implicated in various diseases, including hypertension, arrhythmias, migraine, epilepsy, and neurodegenerative disorders. Therefore, calcium channels are an important target for drug development and therapy.

I'm sorry for any confusion, but "Hyaluronoglucosaminidase" appears to be a made-up term or a typographical error. The correct term related to hyaluronic acid metabolism is "hyaluronidase," which is an enzyme that degrades hyaluronic acid, a component of the extracellular matrix in various tissues. If you meant to ask about this enzyme or its functions, I'd be happy to provide more information on that. However, if "Hyaluronoglucosaminidase" is intended to represent another medical term, could you please clarify so I can provide an accurate and helpful response?

Bicarbonates, also known as sodium bicarbonate or baking soda, is a chemical compound with the formula NaHCO3. In the context of medical definitions, bicarbonates refer to the bicarbonate ion (HCO3-), which is an important buffer in the body that helps maintain normal pH levels in blood and other bodily fluids.

The balance of bicarbonate and carbonic acid in the body helps regulate the acidity or alkalinity of the blood, a condition known as pH balance. Bicarbonates are produced by the body and are also found in some foods and drinking water. They work to neutralize excess acid in the body and help maintain the normal pH range of 7.35 to 7.45.

In medical testing, bicarbonate levels may be measured as part of an electrolyte panel or as a component of arterial blood gas (ABG) analysis. Low bicarbonate levels can indicate metabolic acidosis, while high levels can indicate metabolic alkalosis. Both conditions can have serious consequences if not treated promptly and appropriately.

Culture media is a substance that is used to support the growth of microorganisms or cells in an artificial environment, such as a petri dish or test tube. It typically contains nutrients and other factors that are necessary for the growth and survival of the organisms being cultured. There are many different types of culture media, each with its own specific formulation and intended use. Some common examples include blood agar, which is used to culture bacteria; Sabouraud dextrose agar, which is used to culture fungi; and Eagle's minimum essential medium, which is used to culture animal cells.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Body fluids refer to the various liquids that can be found within and circulating throughout the human body. These fluids include, but are not limited to:

1. Blood: A fluid that carries oxygen, nutrients, hormones, and waste products throughout the body via the cardiovascular system. It is composed of red and white blood cells suspended in plasma.
2. Lymph: A clear-to-white fluid that circulates through the lymphatic system, helping to remove waste products, bacteria, and damaged cells from tissues while also playing a crucial role in the immune system.
3. Interstitial fluid: Also known as tissue fluid or extracellular fluid, it is the fluid that surrounds the cells in the body's tissues, allowing for nutrient exchange and waste removal between cells and blood vessels.
4. Cerebrospinal fluid (CSF): A clear, colorless fluid that circulates around the brain and spinal cord, providing protection, cushioning, and nutrients to these delicate structures while also removing waste products.
5. Pleural fluid: A small amount of lubricating fluid found in the pleural space between the lungs and the chest wall, allowing for smooth movement during respiration.
6. Pericardial fluid: A small amount of lubricating fluid found within the pericardial sac surrounding the heart, reducing friction during heart contractions.
7. Synovial fluid: A viscous, lubricating fluid found in joint spaces, allowing for smooth movement and protecting the articular cartilage from wear and tear.
8. Urine: A waste product produced by the kidneys, consisting of water, urea, creatinine, and various ions, which is excreted through the urinary system.
9. Gastrointestinal secretions: Fluids produced by the digestive system, including saliva, gastric juice, bile, pancreatic juice, and intestinal secretions, which aid in digestion, absorption, and elimination of food particles.
10. Reproductive fluids: Secretions from the male (semen) and female (cervical mucus, vaginal lubrication) reproductive systems that facilitate fertilization and reproduction.

Glycoproteins are complex proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. These glycans are linked to the protein through asparagine residues (N-linked) or serine/threonine residues (O-linked). Glycoproteins play crucial roles in various biological processes, including cell recognition, cell-cell interactions, cell adhesion, and signal transduction. They are widely distributed in nature and can be found on the outer surface of cell membranes, in extracellular fluids, and as components of the extracellular matrix. The structure and composition of glycoproteins can vary significantly depending on their function and location within an organism.

'Staining and labeling' are techniques commonly used in pathology, histology, cytology, and molecular biology to highlight or identify specific components or structures within tissues, cells, or molecules. These methods enable researchers and medical professionals to visualize and analyze the distribution, localization, and interaction of biological entities, contributing to a better understanding of diseases, cellular processes, and potential therapeutic targets.

Medical definitions for 'staining' and 'labeling' are as follows:

1. Staining: A process that involves applying dyes or stains to tissues, cells, or molecules to enhance their contrast and reveal specific structures or components. Stains can be categorized into basic stains (which highlight acidic structures) and acidic stains (which highlight basic structures). Common staining techniques include Hematoxylin and Eosin (H&E), which differentiates cell nuclei from the surrounding cytoplasm and extracellular matrix; special stains, such as PAS (Periodic Acid-Schiff) for carbohydrates or Masson's trichrome for collagen fibers; and immunostains, which use antibodies to target specific proteins.
2. Labeling: A process that involves attaching a detectable marker or tag to a molecule of interest, allowing its identification, quantification, or tracking within a biological system. Labels can be direct, where the marker is directly conjugated to the targeting molecule, or indirect, where an intermediate linker molecule is used to attach the label to the target. Common labeling techniques include fluorescent labels (such as FITC, TRITC, or Alexa Fluor), enzymatic labels (such as horseradish peroxidase or alkaline phosphatase), and radioactive labels (such as ³²P or ¹⁴C). Labeling is often used in conjunction with staining techniques to enhance the specificity and sensitivity of detection.

Together, staining and labeling provide valuable tools for medical research, diagnostics, and therapeutic development, offering insights into cellular and molecular processes that underlie health and disease.

Bovine Serum Albumin (BSA) is not a medical term per se, but a biochemical term. It is widely used in medical and biological research. Here's the definition:

Bovine Serum Albumin is a serum albumin protein derived from cows. It is often used as a stabilizer, an emulsifier, or a protein source in various laboratory and industrial applications, including biochemical experiments, cell culture media, and diagnostic kits. BSA has a high solubility in water and can bind to many different types of molecules, making it useful for preventing unwanted interactions between components in a solution. It also has a consistent composition and is relatively inexpensive compared to human serum albumin, which are factors that contribute to its widespread use.

Therefore, sperm cells go through a process known as the acrosome reaction, which is the reaction that occurs in the acrosome ... the acrosome reaction releases hyaluronidase and acrosin; their role in fertilization is not yet clear. The acrosomal reaction ... which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane ... Since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action ...
This shedding of the acrosome, or acrosome reaction, can be stimulated in vitro by substances a sperm cell may encounter ... This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry or ... "Comparative flow cytometric analysis of the human sperm acrosome reaction using CD46 antibody and lectins". J. Assist. Reprod. ... The acrosome is an organelle that develops over the anterior (front) half of the head in the spermatozoa (sperm cells) of ...
Sperm guidance Acrosome reaction Oocyte Wessel, GM; Brooks, JM; Green, E; Haley, S; Voronina, E; Wong, J; Zaydfudim, V; Conner ... "Egg-jelly signal molecules for triggering the acrosome reaction in starfish spermatozoa". The International Journal of ... The sulfated fucan glycoproteins play an important role in binding to sperm receptors and triggering the acrosomal reaction. ...
To have the ability to fertilize the female gamete, this cell suffers capacitation and acrosome reaction in female reproductive ... This hormone activates AKT that leads to activation of other protein kinases, involved in capacitation and acrosome reaction. ... Gupta, SK; Bhandari, B (January 2011). "Acrosome reaction: relevance of zona pellucida glycoproteins". Asian Journal of ... The basic unit of the Reactome database is a reaction; reactions are then grouped into causal chains to form pathways The ...
Cortical reaction Acrosome reaction Johnson MH (2007). Essential reproduction (6th ed.). Malden Massachusetts: Blackwell ... Lu HY, Lu JC, Hu YA, Wang YM, Huang YF (2002). "[Detection of human sperm morphology and acrosome reaction with Coomassie ... Ozaki T, Takahashi K, Kanasaki H, Miyazaki K (2002). "Evaluation of acrosome reaction and viability of human sperm with two ... These media can be supplemented with other chemicals to induce hyperactivated sperm motility and/or the acrosome reaction. For ...
This is because the acrosome reaction has to take place and thousands of sperm cells have to be involved in IVF. Once ... With this method, the acrosome reaction is skipped. There are several differences between classic IVF and ICSI. However, the ...
This test evaluates the acrosome reaction of human spermatozoa. However, the incidence of acrosome reaction in freely swimming ... "Acrosome reaction of human spermatozoa in zona-free hamster egg penetration test". Fertility and Sterility. 50 (6): 954-9. doi: ...
"Synaptotagmin VI participates in the acrosome reaction of human spermatozoa". Developmental Biology. 235 (2): 521-9. doi: ...
The second process in sperm activation is the acrosome reaction. This involves releasing the contents of the acrosome, which ... As the spermatozoon approaches the egg, it undergoes the acrosome reaction in which the membrane surrounding the acrosome fuses ... There is some evidence that this binding is what triggers the acrosome to release the enzymes that allow the sperm to fuse with ... Above the nucleus lies a cap-like structure called the acrosome, formed by modification of the Golgi body, which secretes the ...
ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal ... This structure binds spermatozoa, and is required to initiate the acrosome reaction. In the mouse (the best characterised ... They bind to capacitated spermatozoa and induce the acrosome reaction. Successful fertilization depends on the ability of sperm ... and enable the acrosome reaction for the successful adhesion and penetration by the sperm cell. Also allows correct embryo ...
... is released from the acrosome of spermatozoa as a consequence of the acrosome reaction. It aids in the penetration of ... Upon stimulus, the acrosome releases its contents onto the zona pellucida. After this reaction occurs, the zymogen form of the ... Thus, some argue for its role in assisting in the dispersal of acrosomal contents following the acrosome reaction, while others ... The importance of acrosin in the acrosome reaction has been contested. It has been found through genetic knockout experiments ...
... F is thereby important to prevent a premature acrosome reaction. Found in Cumulus Oophorus, stimulates binding of ... thereby inhibiting acrosome reaction and sperm-egg binding. Upon de-glycosilation, glycodelin F dissociates from the sperm and ...
... and Protein Tyrosine Phosphorylation on Capacitation and the Spontaneous Acrosome Reaction of Hamster Sperm". Biology of ... "Analysis of CAPZA3 localization reveals temporally discrete events during the acrosome reaction". Journal of Cellular ...
1995). "Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction". Biol. Reprod. 51 (6): 1222-31. ...
Acrosome reaction, cortical reaction and sperm-egg fusion". Zoomorphology. 108 (4): 229-243. doi:10.1007/BF00312223. ISSN 0720- ...
"Sequence of a rabbit sperm zona pellucida binding protein and localization during the acrosome reaction". Dev. Biol. 165 (2): ...
Acrosome reaction - The analogous reaction in the acrosome of the sperm Haley SA, Wessel GM. Sea urchin cortical granules ... The cortical reaction within the egg is analogous to the acrosomal reaction within the sperm, where the acrosome, a specialized ... The cortical reaction is a process initiated during fertilization that prevents polyspermy, the fusion of multiple sperm with ... This modification of the zona pellucida is known as the zona reaction. Although highly conserved across the animal kingdom, the ...
After the acrosome reaction, the sperm is believed to remain bound to the zona pellucida through exposed ZP2 receptors. These ... Additionally, heparin-like glycosaminoglycans (GAGs) are released near the oocyte that promote the acrosome reaction. Fusion ... the binding of the spermatozoon to the GalT initiates the acrosome reaction. This process releases the hyaluronidase that ... "Glycosaminoglycans in Ewe Reproductive Tracts and Their Influence on Acrosome Reactions in Bovine Spermatozoa in Vitro". ...
Acrosome reaction Qi H, Moran MM, Navarro B, Chong JA, Krapivinsky G, Krapivinsky L, et al. (January 2007). "All four CatSper ...
May 2010). "Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice". The ... Increase in phospholipase A2 activity is an acute-phase reaction that rises during inflammation, which is also seen to be ...
... sperm capacitation and acrosome reaction in the excised reproductive tract of hamsters". Theriogenology. 44 (4): 599-608. doi: ...
Heavy metal chelators prolong motility and viability of sea urchin sperm by inhibiting spontaneous acrosome reactions. J. Exp. ...
Normally, spermatozoa fuse with the zona pellucida surrounding the mature oocyte; the resulting acrosome reaction breaks down ... In order to provide protection and immunity for both the mother and her fetus without developing rejection reactions, the ...
2007). "Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody ...
"Effects of Native Human Zona Pellucida Glycoproteins 3 and 4 on Acrosome Reaction and Zona Pellucida Binding of Human ...
It may function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction. ...
... is the glycoprotein in the zona pellucida most important for inducting the acrosome reaction of sperm cells at the ... 2007). "Acrosome reaction induced by recombinant human zona pellucida 3 peptides rhuZP3a22 approximately 176 and rhuZP3b177 ... 2008). "Effects of native human zona pellucida glycoproteins 3 and 4 on acrosome reaction and zona pellucida binding of human ... gene is a major structural component of the ZP and functions in primary binding and stimulation of the sperm acrosome reaction ...
... antibody for the combined assessment of human sperm acrosome integrity and ionophore A23187-induced acrosome reaction". PLOS ...
... plays a role in stimulation of capacitation and inhibition of the spontaneous acrosome reaction". Molecular Reproduction and ...
... could then be followed by the acrosome reaction where the cap-like structure on the head of the cell releases ... Capacitation Acrosome reaction v t e (Articles with short description, Short description matches Wikidata, Articles needing ... Some definitions consider sperm activation to consist of these two processes of hyperactivation and the acrosome reaction ...
Therefore, sperm cells go through a process known as the acrosome reaction, which is the reaction that occurs in the acrosome ... the acrosome reaction releases hyaluronidase and acrosin; their role in fertilization is not yet clear. The acrosomal reaction ... which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane ... Since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action ...
Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm. D L Clapper, D L Clapper ... Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on ... Regulatory mechanisms of the acrosome reaction revealed by multiview microscopy of single starfish sperm. ... Characterization of a monoclonal antibody that induces the acrosome reaction of sea urchin sperm. ...
Please do not hesitate to contact us should you have any queries. You can do so using our chat system on the website, by email to [email protected] or by phone on 087 797 5058. ...
Sabeur, K. ; Vo, A. T. ; Ball, B. A. / Effects of angiotensin II on the acrosome reaction in equine spermatozoa. In: Journal of ... Effects of angiotensin II on the acrosome reaction in equine spermatozoa. / Sabeur, K.; Vo, A. T.; Ball, B. A. In: Journal of ... Sabeur, K., Vo, A. T., & Ball, B. A. (2000). Effects of angiotensin II on the acrosome reaction in equine spermatozoa. Journal ... Sabeur, K, Vo, AT & Ball, BA 2000, Effects of angiotensin II on the acrosome reaction in equine spermatozoa, Journal of ...
Naruse, M., Suetomo, H., Matsubara, T., Sato, T., Yanagawa, H., Hoshi, M., & Matsumoto, M. (2010). Acrosome reaction-related ... Naruse, M, Suetomo, H, Matsubara, T, Sato, T, Yanagawa, H, Hoshi, M & Matsumoto, M 2010, Acrosome reaction-related steroidal ... Acrosome reaction-related steroidal saponin, Co-ARIS, from the starfish induces structural changes in microdomains. In: ... Acrosome reaction-related steroidal saponin, Co-ARIS, from the starfish induces structural changes in microdomains. / Naruse, ...
... undergo capacitation and the acrosome reaction to digest the zona pellucida of the oocyte, attach to the inner membrane, and ... The acrosome, a derivative of the Golgi process, surrounds the nucleus anteriorly and contains enzymes necessary to penetrate ... the formation of the acrosome and flagella, and the migration of cytoplasmic organelles to their final cellular location. ...
This is because the acrosome reaction has to take place and thousands of sperm cells have to be involved in IVF. Once ... With this method, the acrosome reaction is skipped. There are several differences between classic IVF and ICSI. However, the ...
... of PLC zeta in non-capacitated and capacitated sperm and in sperm treated with ionophore to induce the acrosome reaction. ... localized to acrosomal and post-acrosomal regions and undergoes dynamic changes during capacitation and the acrosome reaction, ... Acrosome, Acrosome Reaction, Animals, Blotting, Northern, Cloning, Molecular, Cricetinae, DNA Primers, Immunoblotting, Male, ... C zeta undergoes dynamic changes in its pattern of localization in sperm during capacitation and the acrosome reaction. ...
Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. In: PLoS ONE. 2009 ; Vol. 4, No. 3. ... Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. PLoS ONE. 2009 Mar 23;4(3):e4963. ... Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. / Bátiz, Luis Federico; De Blas, ... Dive into the research topics of Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. ...
NOT involved_in regulation of acrosome reaction IDA Inferred from Direct Assay. more info ... is one of the structural components of the zona pellucida and functions in secondary binding and penetration of acrosome- ...
These Ca2+ and K+ channels are involved in early events of acrosome reactions. Ca2+ channel are susceptible to Cd2+ poisoning ... In both forms of male infertility the ability to undergo an acrosome reaction decreases. Reverse transcriptase-polymerase chain ... acrosome reaction; cadmium; ion channels; lead; male infertility ... reaction assays for Ca2+ and K+ channel isoforms may identify ...
Simons, J.; Fauci, L. A model for the acrosome reaction in mammalian sperm. Bull. Math. Biol. 2018, 80, 2481-2501. [Google ... a variety of environments in order to reach the egg and this process involves a complex choreography of biochemical reactions ...
Sperm from hyh mice carrying a point mutation in alphaSNAP have a defect in acrosome reaction. Bátiz LF, et al. PLoS One, 2009 ... Title: Sperm from hyh mice carrying a point mutation in alphaSNAP have a defect in acrosome reaction. ...
2008) Regulating the acrosome reaction The International Journal of Developmental Biology 52:503-510. ... Nested PCR reactions were performed using for the 1st reaction the primer pair #4791/#4792 and for the 2nd reaction the primer ... We performed two PCR reactions with primer pairs C0991/C0962 and C0417/C0990 and a recombinant PCR reaction on the resulting ... Three PCR reactions were required for each mutation: two with the primers containing the point mutation and one recombinant PCR ...
Increased intracellular Ca2+ concentration plays an important role in the acrosome reaction (Schroeder et al., 1991; Zaneveld ... Capacitation as a regulatory event that primes spermatozoa for the acrosome reaction and fertilization. Mol. Hum. Reprod., 3: ... Inverse relationship between the induction of human sperm capacitation and spontaneous acrosome reaction by various biological ... Singlet oxygen is not a free radical, but can be formed during radical reactions and also cause further reactions. Singlet ...
The acrosome reaction was evaluated using flow cytometry. The radiation did not affect sperm propensity for the acrosome ... 3. P Falzone N et al, (March 2010) The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head ... This study concludes that although RF-EMF exposure did not adversely affect the acrosome reaction, it had a significant effect ... 18.8 +/- 1.4 mum(2)) and acrosome percentage of the head area (21.5 +/- 4% vs. 35.5 +/- 11.4%) was reported among exposed sperm ...
... and acrosome reaction of human spermatozoa. Biol Reprod. 1996 May;54(5):1009-17. doi: 10.1095/biolreprod54.5.1009. Citation on ... This reaction is one step in a process by which the body can use sugars for energy. There are two versions of L-xylulose ... One of its functions is to perform a chemical reaction that converts a sugar called L-xylulose to a molecule called xylitol. ...
Insulin and leptin enhance human sperm motility, acrosome reaction and nitric oxide production FREE Fanuel Lampiao and Stefan S ...
18 It is responsible for initiating the acrosome reaction in capacitated sperm.19 ... Espey LL: Current status of the hypothesis that mammalian ovulation is comparable to an inflammatory reaction. Biol Reprod 50: ...
8a) or the ability to undergo a calcium ionophore induced acrosome reaction (Fig. 8a) differed significantly between the ... induced acrosome reaction and bind zona pellucidae as previously described53,54. Alternatively, 2 × 105 capacitated spermatozoa ... their ability to undergo a calcium ionophore induced acrosome reaction [assessed via peanut agglutinin (PNA) labeling of the ... Thus, these cells retained their ability to capacitate, acrosome react, and bind zona pellucidae at rates that were ...
Effect of cissampelos capensis rhizome extract on human sperm capacitation and acrosome reaction Shalaweh, Salem (2013) ...
Rac1 is necessary for capacitation and acrosome reaction in guinea pig spermatozoa. Journal of cellular biochemistry. 2020. ... This reaction should be performed in an identical manner to the Positive Control reaction except that 1/100th volume of GDP (1 ... The following reaction details how to load endogenous RhoA with the nonhydrolysable GTP analog (GTPγS). This is an excellent ... d) Stop the reaction by transferring the tube to 4°C and adding 1/10th volume of STOP Buffer. ...
Neither of the two physiological inducers of the acrosome reaction (ZP3 or progesterone) can induce acrosome reactions in GalT ... null sperm to ionophore-induced acrosome reactions is not caused by differences in the degree of spontaneous acrosome reactions ... A23187-induced acrosome reaction. Sperm were collected, and at specific points during in vitro capacitation(Fig. 1) a 100 μl ... GalT I-null sperm do not require albumin, Ca2+, or HCO3- during capacitation to undergo an ionophore-induced acrosome reaction ...
... process by which spermatozoa in the ampullary portion of a uterine tube become capable of going through the acrosome reaction ...
Sperm has an absolute requirement for Ca2+ ions to undergo acrosome reaction in preparation for egg fertilization (Ref 2). ...
... known as acrosome reaction (AR), is necessary for natural fertilization. Impaired acrosome reaction results in subfertility or ... subfertility due to impaired acrosome reaction which typically manifests as unexplained subfertility because acrosome reaction ... impaired acrosome reaction (IAR). Acrosome is a single secretory granule present in the head of mammalian sperm and secretion ... regardless whether data for acrosome reaction were available or not. It was shown that the frequency of this stallion ...
Search methods: PubMed searches were performed using the terms sperm structure, capacitation, acrosome reaction, ...
  • In other cases, such as in the wood mouse Apodemus sylvaticus, premature acrosome reactions have been found to cause increased motility in aggregates of spermatozoa promoting fertilization. (
  • Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm. (
  • In the presence of a variety of structurally different metal chelators (0.1-1 mM EDTA, EGTA, phenanthroline, dipyridyl, cysteine, or dithiothreitol), motility initiation is delayed and the acrosome reaction is inhibited. (
  • Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on the sperm pHi was examined by using the fluorescent pH sensitive probe, 9-aminoacridine, EDTA depresses sperm pHi in both species, and 0.1 microM free Zn+2 reverses this pHi depression. (
  • When sperm are diluted into media that contain chelators, both NH4Cl and monensin (a Na+/H+ ionophore) increase the sperm pHi and reverse the chelator inhibition of sperm motility and acrosome reactions. (
  • The results of this study are consistent with the involvement of a trace metal (probably zinc) in the pHi regulation of sea urchin sperm and indicate a likely mechanism for the previously observed effects of chelators on sperm motility and acrosome reactions. (
  • The present study characterized hydrosalpinx epithelial cell culture and examined the effects of its conditioned medium (CM) on sperm motility, acrosome reaction and embryo development. (
  • Sperm motility and acrosome reaction were determined using computer-aided sperm analysis and acrobead assay respectively and embryo development by mouse embryo development assay. (
  • In spermatozoa, several key functions are regulated by cytoplasmic Ca2+ concentration such as sperm capacitation, chemotaxis, hyperactive motility, and acrosome reaction. (
  • Boue F, Blais J, Sullivan R. Surface localization of P34H an epididymal protein, during maturation, capacitation, and acrosome reaction of human spermatozoa. (
  • Sperm Capacitation and Acrosome Reaction in Mammalian Sperm. (
  • Roles of bicarbonate, cAMP, and protein tyrosine phosphorylation on capacitation and the spontaneous acrosome reaction of hamster sperm. (
  • Instead, may protect sperm from premature acrosome reaction in the epididymis by binding to lipid peroxides, which might otherwise interact with phospholipase A2 and induce the acrosome reaction. (
  • However, the ability of SIZP prepared from fer tilized eggs to induce acrosome reaction needs further investigation. (
  • Although angiotensin II as well as progesterone both initiated the acrosome reaction in equine spermatozoa, there was no synergistic effect when both agonists were added simultaneously. (
  • In conclusion, this study demonstrated the ability of angiotensin II to stimulate the acrosome reaction in capacitated equine spermatozoa. (
  • The glycosylated mature peptide is one of the structural components of the zona pellucida and functions in secondary binding and penetration of acrosome-reacted spermatozoa. (
  • 3. P Falzone N et al , (March 2010) The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding of human spermatozoa , Int J Androl. (
  • As the sperm approaches the zona pellucida of the egg, which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane of the sperm's head, exposing the contents of the acrosome. (
  • The acrosomal reaction does not begin until the sperm comes into contact with the oocyte's zona pellucida. (
  • Sperm that did not initiate the acrosome reaction prior to reaching to the zona pellucida are unable to penetrate the zona pellucida. (
  • Since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action of the tail, not because of the acrosome reaction itself. (
  • The acrosome reaction must occur before the sperm cell reaches the zona pellucida. (
  • In this paper, we describe the capacitation phenotype of sperm lacking the long isoform of β1,4-galactosyltransferase I (GalT I), a sperm surface protein that functions as a receptor for the zona pellucida glycoprotein, ZP3, and as an inducer of the acrosome reaction following ZP3-dependent aggregation. (
  • As expected, wild-type sperm must undergo capacitation in order to bind the zona pellucida and undergo a Ca 2+ ionophore-induced acrosome reaction. (
  • By contrast, GalT I-null sperm behave as though they are precociously capacitated, in that they demonstrate maximal binding to the zona pellucida and greatly increased sensitivity to ionophore-induced acrosome reactions without undergoing capacitation in vitro. (
  • Binding to the zona pellucida clusters the sperm receptor, activating intracellular signaling cascades that stimulate the exocytosis of the acrosome. (
  • Required for acrosome reaction in sperm during fertilization, probably by acting as an important enzyme for intracellular Ca2+ mobilization in the zona pellucida-induced acrosome reaction. (
  • In both forms of male infertility the ability to undergo an acrosome reaction decreases. (
  • Egg water from the amphibian Bufo arenarum modulates the ability of homologous sperm to undergo the acrosome reaction in the presence of the vitelline envelope. (
  • Sperm has an absolute requirement for Ca2+ ions to undergo acrosome reaction in preparation for egg fertilization (Ref 2). (
  • A sperm penetration assay includes an acrosome reaction test that assesses how well a sperm can perform during the fertilization process. (
  • The acrosomal reaction usually takes place in the ampulla of the fallopian tube (site of fertilization) when the sperm penetrates the secondary oocyte. (
  • Acrosome reaction is subfamily specific in sea star fertilization. (
  • In the fertilization process of sea stars, sperm is activated to go through the acrosome reaction before cell fusion. (
  • We focused on induction of the acrosome reaction as a key process in fertilization. (
  • Reverse transcriptase-polymerase chain reaction assays for Ca2+ and K+ channel isoforms may identify susceptibility subgroups with lower resistance to environmental exposures. (
  • Acrosome reaction assays indicate that the acrosome reaction can be induced across species within Asteriinae subfamily. (
  • Starvation induces an increase in intracellular calcium and potentiates the progesterone-induced mouse sperm acrosome reaction. (
  • Patrat et al, has shown that solubilized zona prepared from unfertilized and fertilized human eggs induces acrosome reaction and increase in i is mediated by T type VOCC. (
  • GABA also induces acrosome reaction in human sperm. (
  • The acrosome is a membrane-bound organelle of Golgi apparatus origin, commonly located at the tip of the head of mature spermatozoon. (
  • The cortical granules inside the oocyte then fuse to the outer membrane, and a quick fast block reaction occurs. (
  • The first stage is the penetration of corona radiata, by releasing hyaluronidase from the acrosome to digest cumulus cells surrounding the oocyte and exposing acrosin attached to the inner membrane of the sperm. (
  • CONCLUSION(S): Phospholipase C zeta is localized to acrosomal and post-acrosomal regions and undergoes dynamic changes during capacitation and the acrosome reaction, indicating a potential role regulating not only egg activation but other sperm functions. (
  • Anacetrapib Heat solubilized human ZP mediated acrosome reac tion involves activation of Gi protein coupled receptor pathway which is in concordance with previous reports. (
  • Role of T type VOCCs was further reinforced by inhibition of acrosome reaction mediated by human SIZP in presence Inhibitors,Modulators,Libraries of two different T type VOCCs inhibitors. (
  • Further, chelating the e tracellular calcium by EGTA also led to inhibition of SIZP mediated acrosome reac tion. (
  • The initiation of the acrosome reaction by angiotensin II was strongly inhibited by losartan, a specific angiotensin II type 1 receptor antagonist. (
  • Therefore, sperm cells go through a process known as the acrosome reaction, which is the reaction that occurs in the acrosome of the sperm as it approaches the egg. (
  • This is because the acrosome reaction has to take place and thousands of sperm cells have to be involved in IVF. (
  • Studies presented in this manuscript suggest that in humans, ZP mediated induction of acrosome reaction is also inhibited by inhibitor of GABAA receptor. (
  • In contrast to T type VOCCs inhibitors, L type VOCCs inhibitors failed to inhibit SIZP mediated acrosome reaction. (
  • When stimulated with progesterone or A23187 (a calcium ionophore), sperm from these animals had a defective acrosome reaction. (
  • Homotypic fusion among echinoderm egg yolk granules has previously been reconstituted in vitro, and shown to be a rapid, Ca2+-triggered reaction that can produce extremely large (>10 microm diameter) fusion products. (
  • To explain acrosome reaction subfamily specificity at the molecular level, the sugar components of egg jelly were examined and analyzed by principal component analysis. (
  • Picroto in a GABAA receptor inhibitor, inhibits pro gesterone as well as recombinant human ZP3 fragment mediated acrosome reaction. (
  • There are considerable species variations in the morphology and consequences of the acrosome reaction. (
  • In several species, the trigger for the acrosome reaction has been identified in a layer that surrounds the egg. (
  • Therefore, steps after the acrosome reaction are responsible for the species specificity. (
  • Saponins exist in many plants and few animals as self-defensive chemicals, but Co-ARIS has been identified as a cofactor for inducing the acrosome reaction (AR). (
  • Using polymerase chain reaction Mycoplasma hominis and Ureaplasma urealyticum were detected in cervical secretions of 19.2% and 13.7% of infertile women, and the presence of mycoplasma was significantly correlated with the presence of AZP-Ab and ASA. (
  • The protamine status, chromatin structure, chromatin condensation, and acrosome reaction of sperm and assisted reproductive outcomes were determined in couples with different male infertility factors. (
  • Next, we used hamster and mouse models to investigate the localization of PLC zeta in non-capacitated and capacitated sperm and in sperm treated with ionophore to induce the acrosome reaction. (
  • Reduced acrosome reaction and poor mouse embryo development were also observed in hydrosalpinx CM but not in NFT CM and hTF. (
  • A few events precede the actual acrosome reaction. (
  • These Ca2+ and K+ channels are involved in early events of acrosome reactions. (
  • This reaction is one step in a process by which the body can use sugars for energy. (
  • Phospholipase C zeta undergoes dynamic changes in its pattern of localization in sperm during capacitation and the acrosome reaction. (
  • One of its functions is to perform a chemical reaction that converts a sugar called L-xylulose to a molecule called xylitol. (