Acrosome Reaction: 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.Acrosome: 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.Spermatozoa: 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.Sperm Capacitation: 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.Zona Pellucida: A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.Sperm-Ovum Interactions: 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.Sperm Motility: 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.Acrosin: A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.Egg Proteins: Proteins which are found in eggs (OVA) from any species.Ionophores: 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.Calcimycin: 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.Peanut Agglutinin: Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.Vitelline Membrane: The plasma membrane of the egg.Ovum: A mature haploid female germ cell extruded from the OVARY at OVULATION.Sea Urchins: Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.Asterias: A genus of STARFISH in the family Asteriidae. One species, Asterias rubens, is the most common in the north-east Atlantic region.Epididymis: 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.Chlortetracycline: A TETRACYCLINE with a 7-chloro substitution.Fertilization in Vitro: An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.Spermatids: Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.Exocytosis: Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.Semen Preservation: 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).Pimozide: 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)Calcium: 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.Benzamidines: Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.Semen: 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.Sperm Tail: The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.Infertility, Male: The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.Seminal Plasma Proteins: 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.rab3A GTP-Binding Protein: 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 3.6.1.47.Testis: 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.Calcium Ionophores: Chemical agents that increase the permeability of CELL MEMBRANES to CALCIUM ions.Bufo arenarum: A species of the true toads, Bufonidae, found in South America.Spermatogenesis: The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.Sperm Maturation: 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, Electron: 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.Antigens, CD46: 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.Child Care: Care of CHILDREN in the home or in an institution.Progesterone: 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.Lysophosphatidylcholines: Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.Nigericin: A polyether antibiotic which affects ion transport and ATPase activity in mitochondria. It is produced by Streptomyces hygroscopicus. (From Merck Index, 11th ed)Computer User Training: Process of teaching a person to interact and communicate with a computer.Mesocricetus: 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.Sulfuric Acids: Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.Guinea Pigs: 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.Starfish: Echinoderms having bodies of usually five radially disposed arms coalescing at the center.Cervix Mucus: 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)Fluorescein-5-isothiocyanate: 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.Sperm Midpiece: The middle piece of the spermatozoon is a highly organized segment consisting of MITOCHONDRIA, the outer dense fibers and the core microtubular structure.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Smad8 Protein: A receptor-regulated smad protein that undergoes PHOSPHORYLATION by BONE MORPHOGENETIC PROTEIN RECEPTORS and regulates BONE MORPHOGENETIC PROTEIN signaling.Cryopreservation: 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.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Fallopian Tubes: 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.Sus scrofa: A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.Salivary Proline-Rich Proteins: A family of proline-rich proteins that constitute the majority of the protein component of SALIVA. Salivary proline-rich proteins occur as acidic, basic and glycosylated basic proteins. They perform a variety of functions such as adhering to the acquired ENAMEL PELLICLE, acting as lubricants and precipitating TANNINS.ShrewsRadiation Leukemia Virus: A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) isolated from radiation-induced lymphomas in C57BL mice. It is leukemogenic, thymotrophic, can be transmitted vertically, and replicates only in vivo.Follicular Fluid: 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.Sperm Count: A count of SPERM in the ejaculum, expressed as number per milliliter.Elements: 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.Murinae: A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.Monensin: 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.Ejaculation: The emission of SEMEN to the exterior, resulting from the contraction of muscles surrounding the male internal urogenital ducts.FucoseOocytes: 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).Cattle: 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.Glycoconjugates: 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)Fluorescent Antibody Technique, Indirect: 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, Immunoelectron: 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.Strontium Radioisotopes: Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.Pentoxifylline: 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.Plant Lectins: 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.Mice, Inbred ICRSperm Transport: Passive or active movement of SPERMATOZOA from the testicular SEMINIFEROUS TUBULES through the male reproductive tract as well as within the female reproductive tract.Membrane Fusion: 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.Blotting, Western: 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.Fluorescent Antibody Technique: 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.Phospholipase C delta: 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.Aminacrine: 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.Hydrogen-Ion Concentration: 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)Fluorescent Dyes: 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.Calcium Channels: 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.Hyaluronoglucosaminidase: 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.Bicarbonates: 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.Culture Media: 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, Fluorescence: 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.Body Fluids: Liquid components of living organisms.Glottis: The vocal apparatus of the larynx, situated in the middle section of the larynx. Glottis consists of the VOCAL FOLDS and an opening (rima glottidis) between the folds.Staining and Labeling: 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, Bovine: 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)

Extracellular signal-regulated kinases(ERKs), belonging to the family of mitogen-activated protein kinases (MAPKs), are cytoplasmic and nuclear serine/threonine kinases involved in the signal transduction of several extracellular effectors. Recent evidence indicates the presence of p21 Ras and the phosphorylation of ERK1 and ERK2, suggesting the occurrence of the Ras/ERK cascade in mammalian spermatozoa. The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with zona pellucida (ZP). The mitogen-activated protein-kinase inhibitor PD098059 was used as a pharmacological tool to study the involvement of extracellular signal-regulated kinases in the induction of the acrosome reaction in human spermatozoa. This compound significantly inhibited the acrosome reaction induced by both ZP and the calcium ionophore A23187. These results suggest that ERKs are involved in the signal trans-duction pathway through which ZP stimulation works ...
Experiments were designed to determine the interrelationship between cyclic AMP and Ca2+ during the processes of sperm capacitation and the acrosome reaction. In minimal culture media containing pyruvate and lactate as substrates, guinea pig spermatozoa required a minimum of 1.0-1.5 hr to capacitate in the presence of 1.7 mM Ca2+ and a minimum of 0.5-1.0 hr to capacitate in the absence of added Ca2+. Sperm cyclic AMP concentrations were increased by as much as 30-fold within 0.5 min after addition of cells to various media containing Ca2+, and the concentrations then remained increased for up to 4 hr. When the cells were added to several Ca2+-deficient media, however, cyclic AMP concentrations increased only about 3-fold within 0.5 min and then returned to basal concentrations within 2 min. D-600, a calcium transport antagonist, completely blocked the Ca2+-induced increase in sperm cyclic AMP concentrations. In contrast to capacitation, the acrosome reaction failed to occur in the absence of ...
In summary, 2AG affects the in vitro functionality of human sperm by reducing motility, inhibiting capacitation and triggering the acrosome reaction.
TY - JOUR. T1 - EPP and adenosine inhibit spontaneous acrosome loss in boar sperm.. AU - Funahashi, Hiroaki. PY - 1998. Y1 - 1998. M3 - Article. VL - 21. SP - 10. EP - 10. JO - Journal of Reproduction and Fertility, Abstract Series. JF - Journal of Reproduction and Fertility, Abstract Series. ER - ...
Fusion of membranes during the acrosome reaction: a tale of two SNAREs.: During spermiogenesis, hydrolytic enzymes are sorted from the Golgi apparatus to the ac
Recombinant Sperm Acrosome Associated 1 (SPACA1) Protein (GST tag). Species: Human. Source: Wheat germ. Order product ABIN1321048.
Acrosome Definition - The acrosome is a cap that covers the head of the sperm. The acrosome facilitates the acrosomal reaction, which occurs when the...
n. the caplike structure on the front end of a spermatozoon. It breaks down just before fertilization (the acrosome reaction), releasing a number of enzymes that assist penetration between the follicle cells that still surround the ovum. Failure…
Acrosome: | The |acrosome| is an spermatozoa (sperm cells) of many animals. It is a cap-like structur... World Heritage Encyclopedia, the aggregation of the largest online encyclopedias available, and the most definitive collection ever assembled.
Acrosome A small cap overlaying the sperm head. Acrosome Reaction The loss of the acrosome that is necessary for successful fetilization. Normally only
For spermatozoa to gain access to the oocyte for fertilization, lytic enzymes need to be released during the acrosome reaction. These enzymes, which are stored and transported within an organelle termed the acrosome ...
noun Etymology: International Scientific Vocabulary Date: 1899 an anterior prolongation of a spermatozoon that releases egg penetrating enzymes • acrosomal adjective
TY - JOUR. T1 - Recombinant human zona pellucida glycoprotein 3 induces calcium influx and acrosome reaction in human spermatozoa. AU - Brewis, I A. AU - Clayton, R. AU - Barratt, C L. AU - Hornby, D P. AU - Moore, H D. PY - 1996/8/1. Y1 - 1996/8/1. N2 - Recombinant human ZP3 (rhuZP3) generated by Chinese hamster ovary cells transfected with a plasmid containing human ZP3 cDNA was used to study the acrosome reaction (AR) and intracellular calcium fluxes in capacitated human spermatozoa. Conditioned medium containing rhuZP3 significantly induced the AR (P , or = 0.005) in 59.4 +/- 4.7% of spermatozoa (control = 8.5 +/- 3.1%) and caused complete acrosomal loss in a further 17.2 +/- 3.8% of cells (control = 3.7 +/- 0.7%; mean +/- SEM, n = 5). Sperm motility was not affected and acrosomal exocytosis in response to rhuZP3 was also shown to be time-dependent. Basal concentrations of sperm intracellular calcium were measured (82 +/- 7 nM; mean +/- SEM, n = 9). A transient increase in intracellular ...
The principal role of SNARE proteins is to arbitrate vesicle fusion to a target membrane. Formation of tripartite SNARE protein complexes between SNARE proteins on opposing membranes is the minimal requirement for membrane fusion. The SNARE protein family is large, consisting of more than 60 members. A member of the SNARE family, syntaxin, is found on the sperm plasma membrane while synaptobrevin, is found on the outer acrosomal membrane. During the sperm acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the overlying plasma membrane, resulting in release of the acrosomal contents. We hypothesize that syntaxin and synaptobrevin re-localize within the sperm plasma membrane prior to the acrosome reaction to form SNARE complexes and promote membrane fusion at hundreds of specific points. Immunofluorescence was used to localize both syntaxin and synaptobrevin in mouse epididymal sperm before and after capacitation. Sperm were fixed and incubated with antibodies to ...
TY - JOUR. T1 - Characterization of a novel role for the dynamin mechanoenzymes in the regulation of human sperm acrosomal exocytosis. AU - Zhou, Wei. AU - Anderson, Amanda L.. AU - Turner, Adrian P.. AU - De Iuliis, Geoffry N.. AU - McCluskey, Adam. AU - McLaughlin, Eileen A.. AU - Nixon, Brett. PY - 2017/10/1. Y1 - 2017/10/1. N2 - STUDY QUESTION: Does dynamin regulate human sperm acrosomal exocytosis? SUMMARY ANSWER: Our studies of dynamin localization and function have implicated this family of mechanoenzymes in the regulation of progesterone-induced acrosomal exocytosis in human spermatozoa. WHAT IS KNOWN ALREADY: Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied mammalian species. It follows that failure to complete this unique exocytotic event represents a common aetiology in the defective spermatozoa of male infertility patients that have failed IVF in a clinical setting. Recent studies have implicated the dynamin family of mechanoenzymes as ...
In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC). Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam) and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P) pattern and percentages of ARC and non-viable cells (NVC). Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting
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CD52 is a glycosylphosphatidylinositol (GPI)-anchored antigen expressed on lymphocytes and in epididymal epithelial cells. CD52 is also known as maturation-associated sperm antigen but its function is unknown. We therefore generated Cd52 disrupted mice. The resulting Cd52 null mice were healthy, even though Cd52 is expressed on cells of the immune system. We then examined a possible role for CD52 in reproduction. Sperm from Cd52-deficient males were investigated and the viability, motility, morphology, and incidence of spontaneous acrosome reactions were found to be all similar to values for wild-type sperm. In in vitro fertilization system, the sperm showed normal fertilizing ability. As CD52 was found to be transferred onto sperm only after they had migrated into the vas deferens, we examined the behavior of sperm from Cd52-deficient mice in vivo. The mice mated naturally and we observed that a normal number of sperm passed through the uterotubal junction, known to the crucial hurdle for ...
Please distribute: CLARIFICATION: OPEN TO USA AND NON-USA CITIZENS/RESIDENTS POSTDOCTORAL POSITIONS IN MAMMALIAN FERTILIZATION NIH-funded postdoctoral positions are available immediately to study the biochemistry of mammalian gamete recognition. Recent studies show that sperm surface galactosyltransferase is a receptor for ZP3 oligosaccharides in the egg zona pellucida (,fontfamily,,param,Geneva,/param,Nature, 1992, 357:589-593,/fontfamily,). Aggregation of galactosyltransferase by multivalent ZP3 oligosaccharides leads to activation of a heterotrimeric G-protein cascade, which culminates in the acrosome reaction (Science, 1995,,fontfamily,,param,Geneva,/param, 269:1718-1721,/fontfamily,). Although galactosyltransferase-null sperm do not bind ZP3 oligosaccharides nor undergo an acrosome reaction, they still bind to the zona pellucida (Development, 1997,,fontfamily,,param,Geneva,/param, 124:4121-4131,/fontfamily,). This suggests that galactosyltransferase cooperates with other sperm surface ...
The acrosome reaction of epididymal spermatozoa and fertilization in vitro of mouse eggs in chemically defined media without tissue fluid were investigated. About 8 to 10% of motile spermatozoa lost their acrosome but no eggs were penetrated when the spermatozoa and eggs were incubated in a basic medium (modified Krebs-Ringer bicarbonate solution containing glucose) for 5 to 7 hr. Addition of a single metabolic intermediate, such as sodium oxaloacetate or sodium pyruvate, to the basic medium increased the proportion of motile spermatozoa without an acrosome (19 to 34%) and the proportion of eggs penetrated (3·2 to 25·5%). Incubation of spermatozoa and eggs in the basic medium containing serum albumin of various species caused a further increase in the proportion of motile spermatozoa without an acrosome (50 to 65%) and in that of penetrated eggs (60·7 to 86%). The best medium for sperm capacitation and fertilization of mouse eggs in vitro, however, was the basic medium containing bovine serum ...
The male gamete is not completely mature after ejaculation and requires further events in the female genital tract to acquire fertilizing ability, including the processes of capacitation and acrosome reaction. In order to shed light on dynamic protein changes experienced by the sperm cell in preparation for fertilization, a comprehensive quantitative proteomic profiling based on isotopic peptide labeling and liquid chromatography followed by tandem mass spectrometry was performed on spermatozoa from three donors of proven fertility under three sequential conditions: purification with density gradient centrifugation, incubation with capacitation medium, and induction of acrosome reaction by the exposure to the calcium ionophore A23187. After applying strict selection criteria for peptide quantification and for statistical analyses, 36 proteins with significant changes in their relative abundance within sperm protein extracts were detected. Moreover, the presence of peptide residues potentially ...
Beltran,C. Trevino,C.L. Mata-Martinez,E. Chavez,J.C. Sanchez-Cardenas,C. Baker,M. Darszon,A. 2016. Role of Ion Channels in the Sperm Acrosome Reaction en: Buffone,M.G. Sperm Acrosome Biogenesis and Function During Fertilization. Springer International Publishing Switzerland. pags. 35-69 Reyes,J.G. Sanchez-Cardenas,C. Acevedo-Castillo,W. Leyton,P. Lopez-Gonzalez,I. Felix,R. Gandini,M.A. Trevino,M.B. Trevino,C.L. 2014. Maitotoxin: An Enigmatic Toxic Molecule with Useful Applications in the Biomedical Sciences en: Botana,L.M. Seafood and Freshwater Toxins. Pharmacology, Physiology, and Detection. Boca Raton. CRC Press. pags. 677-694 * Indica publicación con otra institución de adscripción. ...
Comparison of Motility, Acrosome, Viability and ATP of Boar Sperm with or without Cold Shock Resistance in Liquid Semen at 17℃ and 4℃, and Frozen-thawed Semen - Boar;Liquid Semen;Motility;Acrosome;ATP;
Membrane lipid regulation of cell function is poorly understood. In early development, sterol efflux and the ganglioside GM1 regulate sperm acrosome exocytosis (AE) and fertilization competence through unknown mechanisms. Here, we show that sterol efflux and focal enrichment of GM1 trigger Ca(2+) influx necessary for AE through CaV2.3, whose activity has been highly controversial in sperm. Sperm lacking CaV2.3s pore-forming α1E subunit showed altered Ca(2+) responses, reduced AE, and a strong subfertility phenotype. Surprisingly, AE depended on spatiotemporal information encoded by flux through CaV2.3, not merely the presence/amplitude of Ca(2+) waves. Using studies in both sperm and voltage clamp of Xenopus oocytes, we define a molecular mechanism for GM1/CaV2.3 regulatory interaction, requiring GM1s lipid and sugar components and CaV2.3s α1E and α2δ subunits. Our results provide a mechanistic understanding of membrane lipid regulation of Ca(2+) flux and therefore Ca(2+)-dependent ...
Calcium signalling plays a pivotal role in sperm physiology, being intimately involved in the regulation of acrosome reaction, chemotaxis and hyperactivation. Here we describe briefly the mechanisms of calcium regulation in somatic cells and the ways in which these mechanisms have been adapted to function in mature spermatozoa. We then consider recent data from this and other laboratories on the responses of sperm to three compounds: progesterone and nitric oxide (both products of the cumulus oophorus) and 4-aminopyridine. All of these compounds induce calcium signals in the posterior sperm head and neck region and, when applied at appropriate concentrations, modify flagellar activity, causing asymmetric bending of the proximal flagellum. We argue that these effects reflect a common mode of action, mobilisation of calcium stored in the sperm neck region. Finally we consider the nature of calcium signalling pathways in sperm. We suggest that this highly specialised and extremely polarised cell, ...
Batiz,L.F. de Blas,G.A. Michaut,M.A. Ramirez,A.R. Rodriguez,F. Ratto,M.H. Oliver,C. Tomes,C.N. Rodriguez,E.M. Mayorga,L.S. 2009. Sperm from hyh mice carrying a point mutation in alphaSNAP have a defect in acrosome reaction PLoS ONE, 4, e4963 * ...
Looking for online definition of acrosome malformation of spermatozoa in the Medical Dictionary? acrosome malformation of spermatozoa explanation free. What is acrosome malformation of spermatozoa? Meaning of acrosome malformation of spermatozoa medical term. What does acrosome malformation of spermatozoa mean?
A specific hypoglycosylated isoform of the complement regulator membrane cofactor protein (MCP; CD46) is expressed on the inner acrosomal membrane (IAM) of spermatozoa. This membrane is exposed after the acrosome reaction, an exocytosis event that occurs upon contact with the zona pellucida. We initiated this investigation to assess MCPs regulatory function in situ on spermatozoa. Upon exposure of human spermatozoa to autologous serum or follicular fluid, we unexpectedly observed that acrosome-reacted spermatozoa activated the complement cascade efficiently through C3 but not beyond. Using FACS to simultaneously evaluate viability, acrosomal status, and complement deposition, we found that complement activation was initiated by C-reactive protein (CRP) and was C1q, C2, and factor B dependent. This pattern is consistent with engagement of the classical pathway followed by amplification through the alternative pathway. C3b deposition was targeted to the IAM, where it was cleaved to C3bi. Factor ...
A specific hypoglycosylated isoform of the complement regulator membrane cofactor protein (MCP; CD46) is expressed on the inner acrosomal membrane (IAM) of spermatozoa. This membrane is exposed after the acrosome reaction, an exocytosis event that occurs upon contact with the zona pellucida. We initiated this investigation to assess MCPs regulatory function in situ on spermatozoa. Upon exposure of human spermatozoa to autologous serum or follicular fluid, we unexpectedly observed that acrosome-reacted spermatozoa activated the complement cascade efficiently through C3 but not beyond. Using FACS to simultaneously evaluate viability, acrosomal status, and complement deposition, we found that complement activation was initiated by C-reactive protein (CRP) and was C1q, C2, and factor B dependent. This pattern is consistent with engagement of the classical pathway followed by amplification through the alternative pathway. C3b deposition was targeted to the IAM, where it was cleaved to C3bi. Factor ...
Calcium flux is required for the mammalian sperm acrosome reaction, an exocytotic event triggered by egg binding, which results in a dramatic rise in sperm intracellular calcium. Calcium-dependent membrane fusion results in the release of enzymes that facilitate sperm penetration through the zona pellucida during fertilization. We have characterized inositol 1,4,5-trisphosphate (IP3)-gated calcium channels and upstream components of the phosphoinositide signaling system in mammalian sperm. Peptide antibodies colocalized G alpha q/11 and the beta 1 isoform of phospholipase C (PLC beta 1) to the anterior acrosomal region of mouse sperm. Western blotting using a polyclonal antibody directed against purified brain IP3 receptor (IP3R) identified a specific 260 kD band in 1% Triton X-100 extracts of rat, hamster, mouse and dog sperm. In each species, IP3R immunostaining localized to the acrosome cap. Scatchard analysis of [3H]IP3 binding to rat sperm sonicates revealed a curvilinear plot with high ...
TY - JOUR. T1 - Evaluation of acrosome integrity in epidydimal alpaca sperm by flow cytometry. AU - Ugarelli, Alejandra. AU - Evangelista-Vargas, Shirley. AU - Santiani, Alexei. PY - 2017/1/1. Y1 - 2017/1/1. N2 - The aim of this study was to determine the percentage of epidydimal sperm acrosome integrity using alpaca Arachis hypogaea (PNA) and Pisum sativum (PSA), combined with fluorescein isothiocyanate (FITC). Testicles (n=45) were obtained at Ninacaca municipal slaughterhouse (Pasco, Peru). Only 29 samples with motility higher than 30% and concentration higher than 50x106 sperm/ml were used. Sperm from cauda epididymis were recovered with 1 ml of Tris base solution, and then, washed by centrifugation at 600 g for 8 min and pellets were re-suspended in 300 μl of PBS. Each sample was divided into two aliquots and incubated for 8 min at 38 °C with FITC-PNA (0.5 μg/ml) or FITC-PSA (2.5 μg/ mL) together with propidium iodide (PI, 0.5 μg/ml) as a viability marker. Samples were evaluated by ...
Aside from its importance in understanding specific aspects of fertilization, studies on sperm - egg interaction provide an elegant general model to study intercellular communication and cellular...
In the mouse and other mammals studied, including man, ejaculated spermatozoa cannot immediately fertilize an egg. They require a certain period of residence in the female genital tract to become functionally competent cells. As spermatozoa traverse through the female genital tract, they undergo multiple biochemical and physiological changes collectively referred to as capacitation. Only capacitated spermatozoa interact with the extracellular egg coat, the zona pellucida. The tight irreversible binding of the opposite gametes triggers a Ca|sup|2+|/sup|-dependent signal transduction cascade. The net result is the fusion of the sperm plasma membrane and the underlying outer acrosomal membrane at multiple sites that causes the release of acrosomal contents at the site of sperm-egg adhesion. The hydrolytic action of the acrosomal enzymes released, along with the hyperactivated beat pattern of the bound spermatozoon, is important factor that directs the sperm to penetrate the egg coat and fertilize the egg.
Sea urchin and human sperm contain receptors for neurotransmitters and psychoactive drugs, including cannabinoid receptors (CNRs). Anandamide, arachidonoylethanolamide (AEA), is a lipid-signal molecule that is an endogenous agonist for CNRs. AEA is enyzmatically released from membrane phospholipids when neurons are stimulated. Retrograde AEA signals from depolarized postsynaptic neurons inhibit neurotransmitter release at synapses in mammalian brain. Analogous processes regulate sperm functions during fertilization in sea urchins. AEA and (-)delta9tetrahydrocannabinol [(-)delta9THC], the major psychoactive constituent of marijuana, inhibit fertilization by blocking acrosomal exocytosis/acrosome reactions (AR) stimulated by egg jelly. The acrosome is a Golgi-derived secretory granule in sperm analogous to synaptic vesicles in neurons. AEA and (-)delta9THC do not block ionophore-induced AR, suggesting that they inhibit AR by modulating signal transduction event(s) before opening of ion channels. ...
E-mail: [email protected] Abstract: Actin polymerization and development of hyperactivated (HA) motility are two processes that take place during sperm capacitation. Actin polymerization occurs during capacitation and prior to the acrosome reaction fast F-actin breakdown take place. The increase in F-actin during capacitation depends upon inactivation of the actin severing protein, gelsolin, by its binding to phosphatydilinositol-4, 5-bisphosphate (PIP2) and its phosphorylation on tyrosine-438 by Src. Activation of gelsolin by causing its release from PIP2 caused F-actin breakdown and inhibition sperm motility, which could be restored by adding PIP2 to the cells. Reduction of PIP2 synthesis inhibited actin polymerization and motility, and increasing PIP2 synthesis enhanced these activities. Furthermore, sperm demonstrating low motility contained low levels of PIP2 and F-actin. During capacitation there was an increase in PIP2 and F-actin levels in the sperm head and a decrease in the tail. ...
Biology is the study of life and its processes. Biologists study all aspects of living things, including all of the many life forms on earth and the processes in them that enable life. These basic processes include the harnessing of energy, the synthesis and duplication of the materials that make up the body, the reproduction of the organism and many other functions. Biology, along with chemistry and physics is one of the major disciplines of natural science. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Level Biology - abiogenesis - absorption spectrum - acclimatization - acetyl CoA - acrosome - acrosome reaction - actin - action potential - activation energy - active site - active transport - adaptation - adaptive radiation - Adenosine triphosphate (ATP) - Adenosine diphosphate (ADP) - aerobic respiration - affinity chromatography - albinism - albumin - alcohol - Alexander Fleming - Alfred Russel Wallace - algae - allele - allele frequency - allosteric site - allostery - alpha helix - ...
Synonyms for acrosomal in Free Thesaurus. Antonyms for acrosomal. 7 words related to acrosome: sperm, sperm cell, spermatozoan, spermatozoon, appendage, outgrowth, process. What are synonyms for acrosomal?
A sperm cell is described as having a "head" section and a "tail" section. The head, which is shaped like a flattened oval, contains most of the cellular components, including DNA. The head also contains an important structure called an acrosome, which is basically a sac containing enzymes that will help the sperm fuse with an egg (more about the acrosome below). The role of the tail portion of sperm is to act as a propeller, allowing these cells to "swim." At the top of the tail, near where it meets the head, are a ton of tiny structures called mitochondria. These kidney-shaped components are the powerhouses of all cells, and they generate the energy required for the sperm tail to move the sperm toward its target: the egg. ...
A 45-kDa protein was originally extracted from a depression, where the acrosome is lodged, on the anterior end of the sperm nucleus of ejaculated wallaby spermatozoa. Using immunofluorescent and confocal […]. ...
1. Daneva T, Zierhut B, Gartner W, & Wagner L. Fine tuning of insulin transcription by secretagogin variants. Comp. Rend. Bulg. Acad. Sci. 8: 983-988 (2005). ISSN: 1310-1331, IF-0.204 2. Vangelov I, Dineva J, Nikolov G, Genov M, Ivanova M. Anti-granulosa antibodies (AGA) in follicular fluids and their impact to controlled ovarian hyperstimulation and on the fertilization rate. Comp. Rend. Bulg. Acad. Sci. 59: 1191-96 (2006). ISSN: 1310-1331, IF-0.204. 3. Dineva J, Vangelov I, Nikolov G, Gulenova D, Ivanova M. Apoptosis of human Granulosaluteinized (GLCs) and Cumulus cells(CCs) as a possible indicator for IVF outcome. Comp. Rend. Bulg. Acad., 59: 781-784 (2006) ISSN: 1310-1331, IF-0.204. 4. Mollova M, Martinova Y. Immunocytochemical localization of antigen involved in sperm-zona pellucida interaction. Acta Morphol. et Antropol., 13, 98-101 (2006). ISSN 0861-0509. 5. Martinova Y, Mollova M, Petrov M, Rashev P, Ivanova M. TEM and SEM characteristics and lectin binding distribution of cat zona ...
Effect of relaxin on human sperm functions.: Relaxin is a circulating hormone with functions in pregnancy, parturition, and other aspects of female reproduction
TY - JOUR. T1 - Adverse effects of cadmium exposure on mouse sperm. AU - Oliveira, Helena. AU - Spanò, Marcello. AU - Santos, Conceição. AU - Pereira, Maria de Lourdes. PY - 2009/12. Y1 - 2009/12. N2 - The effects of cadmium chloride exposure on sperm functional parameters were evaluated on eight-week-old ICR-CD1 male mice administered with a single s.c. injection of 1, 2 and 3 mg CdCl2/kg bw. Groups of animals treated with each dose, as well as their respective controls, were sacrificed after 24 h to detect short-term (acute) effects and after 35 days. Sperm cells were collected from the epididymis and several parameters of sperm quality and function were evaluated, namely density, morphology, motility, viability, mitochondrial function, acrosome integrity, together with DNA fragmentation assessed by the TUNEL assay. The short-term effects of cadmium chloride resulted in an increased fraction of sperm with abnormal morphology, premature acrosome reaction and reduced motility. Late term ...
Neoglycoproteins with N-acetylglucosamine residues (BSA-GlcNAc) induced specifically the acrosome reaction (AR) in human spermatozoa. Our objective was to investigate the relationship between this phenomenon and the invitro fertilization (IVF) rate. Sperm suspensions from IVF protocols were incubated with BSA-GlcNAc (t), using calcium ionophore (i) or medium alone (c) as positive or negative controls. When the normalized AR percentage ratio (STIM) (% ARt-%ARc):(%ARi-%ARc) was compared with fertilization rate in 31 couples from our IVF programme, a positive correlation was found (r = 0.46, P , 0.01). The fertilization rate in patients with STIM , or = 0.2 was higher than in non-responders (STIM , 0.2); 72 +/- 7% compared with 5 +/- 3%. The overall predictive value of this test for adequate fertilization rate (, 30%) was 87%, sensitivity 91% and specificity 78%. False positives were 9% and false negatives 22%. For successful fertilization rates (, 60%), the results were: overall predictive value, ...
This study demonstrated that bovine sperm exposure to GAGs positively affected sperm fertilizing ability, in vitro embryo developmental potential, and embryonic gene expression. This is the first report to determine concurrently the effects of four different GAGs (HP, HA, CD, and DS). HP was the most potent GAG for enhancing sperm motility and inducing the acrosome reaction. HP exposed sperm exhibited improved 2 PN formation, cleavage rate, blastocyst formation rate, and embryo cell numbers relative to the control (p,0.05). Additionally, in embryos developing from fertilization with HP-treated sperm significant changes in gene expression were detected in genes involved in pluripotency (Oct4, upregulated), apoptosis (Bax inhibitor, upregulated; Caspase 3, downregulated), and cell growth (Glut5, upregulated), relative to control embryo gene expression (p,0.05). Sperm exposure to HA resulted in intermediate levels of changes, and, similar to HP, HA treatment of sperm resulted in significantly ...
An acrosomes is the "cap" at the anterior end of a sperm cell that produces enzymes to facilitate depth of the egg.. Dr. Saint David R. J. Glenn and colleagues information that viagra pic, compared to no view, led to a "sustained enhancement of move," both in Numbers of progressively motile sperm and their velocity.. However, photography to sildenafil - at concentrations relative atomic mass to the mean upper limit sum state density gift 30 minutes after a safety oral dose of 100 milligrams - also led to early activity of the acrosome chemical change. "This has important clinical implications because sperm that acrosome-react before inter-group communication with the oocyte are incapable of fecundation," the researchers note.. "Given that the figure of sperm acrosome react on representation to sildenafil, the drug may proceedings significant debasement to their fertilizing potential drop," they add.. This is a business concern, Dr.Glenn and colleagues say, given that viagra and other ...
Mouse monoclonal antibody raised against native Intra-acrosomal protein. Native purified human intra-acrosomal protein. (MAB3618) - Products - Abnova
ZPBP is one of several proteins that are thought to participate in secondary binding between acrosome-reacted sperm and the egg-specific extracellular matrix, the zona pellucida (McLeskey et al., 1998 [PubMed 9378618]).[supplied by OMIM, Aug 2008 ...
Effect of micromolar concentration of Met-AEA on bull heparin-induced sperm capacitation.Spermatozoa were incubated for 45 min at 38.5°C in sp-TALP medium with
Ovulation is the time during a womens cycle when eggs are released from the ovaries into the fallopian tub. In order to get pregnant, sperm must be present
Hiring a professional to undertake cheap air conditioning installation Manly certainly gives you peace of mind. You can be certain that the unit comes with a warranty that offers protection in case the system wears, breaks or fails to operate as required.. Air conditioning in a house comes with tremendous benefits. Having these systems installed in your house properly is key to enjoying these benefits. Since installation might be quite daunting, finding professionals is a prudent idea. Experts such as Balmoral Air Conditioning Services make the whole process a lot easier. Professionals ascertain quality services beyond any reasonable doubt.. ...
... could then be followed by the acrosome reaction where the cap-like structure on the head of the cell releases ... Some definitions consider sperm activation to consist of these two processes of hyperactivation and the acrosome reaction ...
"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. ...
This is due to the fact that in IVF acrosome reaction has to take place and thousands of sperm cells have to be involved. Once ... With this method acrosome reaction is skipped. ICSI is used in the 95% of oocytes in the world. ...
After the acrosome reaction, the sperm is believed to remain bound to the zona pellucida through exposed ZP2 receptors. These ... In mammals, the binding of the spermatozoon to the GalT initiates the acrosome reaction. This process releases the ... Unlike sea urchins, the sperm binds to the egg before the acrosomal reaction. ZP3, a glycoprotein in the zona pellucida, is ... to the N-acetylglucosamine residues on the ZP3 and is important for binding with the sperm and activating the acrosome reaction ...
This is due to the fact that in IVF acrosome reaction has to take place and thousands of sperm cells have to be involved. Once ... With this method acrosome reaction is skipped. There are several differences within classic IVF and ICSI. However, the steps to ...
Phospholipase C (PLC) is involved in acrosome reaction. ZP3 is a glycoprotein present in zona pelucida and it interacts with ... 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 (Jan 2011). "Acrosome reaction: relevance of zona pellucida glycoproteins". Asian Journal of Andrology. ...
The second process in sperm activation is the acrosome reaction. This involves releasing the contents of the acrosome, which ... 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 ...
This test evaluates the acrosome reaction of human spermatozoa. However, the incidence of acrosome reaction in freely swimming ... Yang, YS; Rojas, FJ; Stone, SC (Dec 1988). "Acrosome reaction of human spermatozoa in zona-free hamster egg penetration test". ...
"Synaptotagmin VI participates in the acrosome reaction of human spermatozoa". Developmental Biology. 235 (2): 521-9. doi: ...
... 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 ...
"Roles of Bicarbonate, cAMP, and Protein Tyrosine Phosphorylation on Capacitation and the Spontaneous Acrosome Reaction of ... "Analysis of CAPZA3 localization reveals temporally discrete events during the acrosome reaction". Journal of Cellular ...
This structure binds spermatozoa, and is required to initiate the acrosome reaction. In the mouse (the best characterised ... ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal ... ZP3 and ZP4 bind to capacitated spermatozoa and induce the acrosome reaction. Successful fertilization depends on the ability ...
1995). "Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction". Biol. Reprod. 51 (6): 1222-31. ...
"Sequence of a rabbit sperm zona pellucida binding protein and localization during the acrosome reaction". Dev. Biol. 165 (2): ...
Cortical reaction Acrosome reaction Essential Reproduction, Johnson, 6th edition, Blackwell Publishing Lozano G.M., Bejarano, I ... After this capacitation, the sperm must undergo the final maturation step, activation, involving the acrosome reaction. ...
"Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice". The Journal of ... Increase in phospholipase A2 activity is an acute-phase reaction that rises during inflammation, which is also seen to be ...
In vivo assessment of the human sperm acrosome reaction and the expression of glycodelin-A in human endometrium after ... The in vitro effect of levonorgestrel on the acrosome reaction of human spermatozoa from fertile men. „Contraception". 68 (1), ... Effect of copper ion on the motility, viability, acrosome reaction and fertilizing capacity of human spermatozoa in vitro. „ ...
... 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 ...
Once this occurs, the sperm is capable of binding with the zona pellucida, and the acrosome reaction can occur. Meyer, K (1971 ... In most mammalian fertilization, hyaluronidase is released by the acrosome of the sperm cell after it has reached the oocyte, ... a scheme based on the enzyme reaction products. The three main types of hyaluronidases are two classes of eukaryotic ...
2007). "Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody ...
The cortical reaction and acrosome reaction are both essential to ensure that only one sperm will fertilize an egg. After the ... preparing it for the acrosome reaction, the enzymatic penetration of the egg's tough membrane, the zona pellucida, which ... In preparation for the fusion of their genetic material both the oocyte and the sperm undergo transformations as a reaction to ... Upon encountering the secondary oocyte, the acrosome of the sperm produces enzymes which allow it to burrow through the outer ...
"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. ...
... by means of the peroxidation reaction: H. 2. O. 2. +. R. ′. H. 2. →. R. ′. +. 2. H. 2. O. {\displaystyle \mathrm {H} _{2}\ ... catalase converts it to H2O through this reaction: 2. H. 2. O. 2. →. 2. H. 2. O. +. O. 2. {\displaystyle 2\mathrm {H} _{2}\ ... The first reactions in the formation of plasmalogen in animal cells also occur in peroxisomes. Plasmalogen is the most abundant ... This reaction is important in liver and kidney cells, where the peroxisomes detoxify various toxic substances that enter the ...
Recombinant human zona pellucida glycoprotein 3 induces calcium influx and acrosome reaction in human spermatozoa. / Brewis, I ... Recombinant human zona pellucida glycoprotein 3 induces calcium influx and acrosome reaction in human spermatozoa. Molecular ... title = "Recombinant human zona pellucida glycoprotein 3 induces calcium influx and acrosome reaction in human spermatozoa", ... T1 - Recombinant human zona pellucida glycoprotein 3 induces calcium influx and acrosome reaction in human spermatozoa ...
keywords = "Acrosome reaction, Dynamin, Human spermatozoa, Infertility, Sperm maturation",. author = "Wei Zhou and Anderson, { ... WHAT IS KNOWN ALREADY: Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied ... Recent studies have implicated the dynamin family of mechanoenzymes as important regulators of the acrosome reaction in murine ... WHAT IS KNOWN ALREADY: Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied ...
... sperm capacitation and the acrosome reaction, sperm binding and penetration of the zona pellucida, zona reaction, gamete fusion ...
Therefore, sperm cells go through a process known as the acrosome reaction which is the reaction that occurs in the acrosome of ... 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 ... The acrosome reaction can be stimulated in vitro by substances a sperm cell may encounter naturally such as progesterone or ...
What is Acrosome reaction? Meaning of Acrosome reaction as a finance term. What does Acrosome reaction mean in finance? ... Definition of Acrosome reaction in the Financial Dictionary - by Free online English dictionary and encyclopedia. ... Related to Acrosome reaction: Cortical reaction, capacitation. Reaction. A decline in prices following an advance. Opposite of ... Acrosome reaction financial definition of Acrosome reaction https://financial-dictionary.thefreedictionary.com/Acrosome+ ...
These results suggest that the sperm acrosome reaction is associated with both a primary transport of Ca2+ and a Ca2+-dependent ... Because a cyclic AMP analogue did not induce an acrosome reaction in the absence of added Ca2+, the increase in sperm cyclic ... In contrast to capacitation, the acrosome reaction failed to occur in the absence of extracellular Ca2+. After capacitation of ... Calcium-dependent increase in adenosine 3′,5′-monophosphate and induction of the acrosome reaction in guinea pig spermatozoa. ...
Find out information about acrosome reaction. A form of cellular exocytosis that allows sperm to penetrate the zona pellucida ... Related to acrosome reaction: Cortical reaction, capacitation. acrosome reaction. [′ak·rə‚sōm rē‚ak·shən] (cell and molecular ... Acrosome reaction , Article about acrosome reaction by The Free Dictionary https://encyclopedia2.thefreedictionary.com/acrosome ... a href=https://encyclopedia2.thefreedictionary.com/acrosome+reaction,acrosome reaction,/a,. *Facebook ...
Acrosome Reaction. Abstract:. The principal role of SNARE proteins is to arbitrate vesicle fusion to a target membrane. ... During the sperm acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the overlying plasma membrane ... Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction. Welcome to the IDEALS Repository. ... We hypothesize that syntaxin and synaptobrevin re-localize within the sperm plasma membrane prior to the acrosome reaction to ...
Stival C, Puga Molina Ldel C, Paudel B, Buffone MG, Visconti PE, Krapf D. Sperm Capacitation and Acrosome Reaction in Mammalian ...
Aquí, dos ensayos de rendimiento medio para la evaluación de efectos sobre la Ca2 +-reacción señalización y acrosómica en...
This suggests that the acrosome reaction results in presentation of at least one novel epitope which plays a role in sperm- ... When sperm were induced to undergo the acrosome reaction with A23187 and incubated with their discharged acrosomal contents, a ... Formaldehyde fixation of acrosome-intact sperm caused partial rupture of the acrosome with loss of the characteristic rouleaux ... Acrosome-intact mammalian sperm can adhere to zona pellucida-free oocytes but are only capable of fusing if they have ...
... acrosome reaction, motility and cryopreservation, Reviews in Fish Biology and Fisheries" on DeepDyve, the largest online rental ... Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction,... Alavi, Sayyed; Hatef, ... Egg water, Ca2+ and Mg2+ can trigger acrosome reaction. Trypsin- and chymotrypsin-like activities are reported in sturgeon ... Egg water, Ca2+ and Mg2+ can trigger acrosome reaction. Trypsin- and chymotrypsin-like activities are reported in sturgeon ...
... Franken D.R. ; Bastiaan H.S. ; Kidson A. ; Wranz P. ; Habenicht ... spontaneous and calcium ionophore induced acrosome reaction. Predictive values for acrosome responsiveness were depicted with ... After completion of acrosome reaction studies, patient samples were divided according to the percentage of morphologically ... Sperm samples from 29 men randomly selected from the andrology laboratory, were used to evaluate acrosome reaction response to ...
... induces the acrosome reaction (AR) in stallion spermatozoa and, if so, to identify the component in FF responsible for it. ... Viable spermatozoa without the outer acrosomal membrane were considered as physiologically acrosome-reacted. Results showed ... The aim of this study was to investigate whether mare follicular fluid (FF) induces the acrosome reaction (AR) in stallion ... Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to ...
2012): RE:The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding ... Lerchl A (2012): Letter on The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry ... The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding of human ... The irradiation did not affect the acrosome reaction. The analysis of morphometric parameters revealed a statistically ...
ACROSOME REACTION The red receptors on the sperm come into contact with the egg jelly, yellow. This induces the acrosome ... reaction causing the acrosome in green to fuse with the plasma membrane of the sperm. The actin in pink goes from a globular ...
... like protein during the acrosome reaction (AR) of normal sperm donors and (ii) the role of intact acrosomes during sperm-zone ... G-protein regulation of the solubilized human zona pellucida-mediated acrosome reaction and zona pellucida binding  Bastiaan H ... The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with ... The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with ...
... a maturation step preceding acrosome reaction. Recent studies have reported leptin ability to promote capacitation and acrosome ... Furthermore, the inhibitory effect of L-NAME and of Ab-ObR on the promotion of acrosome reaction triggered by leptin suggests a ... Significant increases of nitric oxide levels and acrosome reaction extent were detected in leptin-treated spermatozoa, but both ... In addition, acrosome status of treated-spermatozoa was evaluated by FITC-PNA staining. ...
Stimulation of both capacitation and acrosome reaction resulted from sequential exposure to pentoxifylline and progesterone. ... After exposure to pentoxifylline (1 mg/ml; 30 min), the fluorescent B pattern, characteristic of capacitated, acrosome-intact ... acrosome loss and hyperactivation. Sperm viability was not affected in any treatment group. These observations suggest that ... cells, increased significantly (P , 0.01), though no increase in AR pattern, characteristic of acrosome-reacted cells, was ...
Human Sperm Acrosome Reaction. Patrick F nichel, Jean Parinaud - Fertilization (Biology) - 1995 - 460 pages. ...Human homolog ...
... study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome- ... plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red ... Evaluation of Acrosome Reaction. Acrosome status was monitored with acrosome-specific FITC-labeled peanut (Arachis hypogaea) ... Effect of Asta on Sperm Viability and Acrosome Reaction (AR). At the end of incubation, aliquots of sperm suspensions were ...
Moreover, an absence of $Ca^{2+}$ or $HCO_3{^-}$ inhibited in vitro hyperactivation and acrosome reaction and decreased the ... hyperactivation and acrosome reaction in guinea pig sperm. Caudal epididymal sperm were incubated in four different groups: ... Hyperactivation and Acrosome Reaction in Guinea Pig Sperm Acrosome Reaction;Capacitation;Hyperactivation;Tyrosine ... A molecular membrane model of sperm capacitation and the acrosome reaction of mammalian spermatozoa. Gamete Res. 12:183-224. ...
Effects on human sperm function was assessed using an image cytometry-based acrosome reaction assay and the modified Kremers ... Effects on human sperm function was assessed using an image cytometry-based acrosome reaction assay and the modified Kremers ... Assessment of Acrosome Reaction. The amount of live acrosome reacted sperm cells was measured using an image cytometry-based ... Medium-throughput screening assays for assessment of effects on Ca2+-Signaling and acrosome reaction in human sperm. J Vis Exp ...
Fusion of membranes during the acrosome reaction: a tale of two SNAREs.: During spermiogenesis, hydrolytic enzymes are sorted ... Fusion of membranes during the acrosome reaction: a tale of two SNAREs.. Authors * Kierszenbaum, A L ... Syntaxin 2, a v-SNARE member, and Rab3A, a member of the Rab GTPases, have been localized in the acrosome of rodent sperm. ... At fertilization, the enzymatic content of the acrosome is released by exocytosis when a portion of the plasma membrane ...
  • In addition, we assessed the influence of selective dynamin inhibition on the competence of human spermatozoa to undergo a progesterone-induced acrosome reaction. (edu.au)
  • Recombinant human ZP3 (rhuZP3) generated by Chinese hamster ovary cells transfected with a plasmid containing human ZP3 cDNA was used to study the acrosome reaction (AR) and intracellular calcium fluxes in capacitated human spermatozoa. (dundee.ac.uk)
  • Recent studies have implicated the dynamin family of mechanoenzymes as important regulators of the acrosome reaction in murine spermatozoa. (edu.au)
  • Human semen samples were fractionated via density gradient centrifugation and the resultant populations of good and poor quality spermatozoa were induced to capacitate and acrosome react in the presence or absence of selective dynamin inhibitors. (edu.au)
  • The acrosome integrity of live spermatozoa was subsequently assessed via the use of fluorescently conjugated Arachis hypogea lectin (PNA). (edu.au)
  • Such findings are of potential significance given that the poor quality spermatozoa proved refractory to the induction of a progesterone stimulated acrosome reaction. (edu.au)
  • WIDER IMPLICATIONS OF THE FINDINGS: This study identifies a novel causative link between dynamin activity and the ability of human spermatozoa to complete a progesterone-induced acrosome reaction. (edu.au)
  • WHAT IS KNOWN ALREADY: Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied mammalian species. (edu.au)
  • Results showed that syntaxin-positive volume and syntaxin content remained the same in capacitated and non-capacitated sperm but the location of syntaxin after capacitation was more restricted to the apical ridge of the plasma membrane overlying the acrosome in more than 90% of the sperm observed. (illinois.edu)
  • Cryosections of acrosome-intact sperm labelled indirectly with immuno-gold showed labelling consistent with the same location, as well as sporadic labelling at other intracellular sites overlying the acrosome. (biologists.org)
  • Therefore, the expression of intracellular NOS enzymes has been also assessed and the possible involvement of NO in acrosome reaction triggered by leptin has been evaluated. (biomedcentral.com)
  • p>This subsection of the 'Function' section describes an enzyme regulatory mechanism and reports the components which regulate (by activation or inhibition) the reaction. (uniprot.org)
  • section describes regulatory mechanisms for enzymes, transporters or microbial transcription factors, and reports the components which regulate (by activation or inhibition) the reaction. (uniprot.org)
  • Indirect immunofluorescence labeling showed type I inositol 1,4,5-trisphosphate receptors (IP 3 R) in the acrosome and neck region, but no ryanodine receptors (RyR) were found using anti-RyR antibodies or BODIPY FL-X ryanodine. (bioone.org)
  • This compound significantly inhibited the acrosome reaction induced by both ZP and the calcium ionophore A23187. (sun.ac.za)
  • We further found that SUMO-1 was lost if the acrosome reaction was induced by calcium ionophore A23187. (frontiersin.org)
  • Capacitation is a set of alterations leading to the acrosome reaction (AR), an exocytotic process by means of which hydrolytic enzymes (e.g., acrosin) are released to allow sperm to fertilize oocytes [ 1 ]. (mdpi.com)