Testosterone: A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.Testosterone Propionate: An ester of TESTOSTERONE with a propionate substitution at the 17-beta position.Hypogonadism: Condition resulting from deficient gonadal functions, such as GAMETOGENESIS and the production of GONADAL STEROID HORMONES. It is characterized by delay in GROWTH, germ cell maturation, and development of secondary sex characteristics. Hypogonadism can be due to a deficiency of GONADOTROPINS (hypogonadotropic hypogonadism) or due to primary gonadal failure (hypergonadotropic hypogonadism).Androgens: Compounds that interact with ANDROGEN RECEPTORS in target tissues to bring about the effects similar to those of TESTOSTERONE. Depending on the target tissues, androgenic effects can be on SEX DIFFERENTIATION; male reproductive organs, SPERMATOGENESIS; secondary male SEX CHARACTERISTICS; LIBIDO; development of muscle mass, strength, and power.Orchiectomy: The surgical removal of one or both testicles.Dihydrotestosterone: A potent androgenic metabolite of TESTOSTERONE. It is produced by the action of the enzyme 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE.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.Sex Hormone-Binding Globulin: A glycoprotein migrating as a beta-globulin. Its molecular weight, 52,000 or 95,000-115,000, indicates that it exists as a dimer. The protein binds testosterone, dihydrotestosterone, and estradiol in the plasma. Sex hormone-binding protein has the same amino acid sequence as ANDROGEN-BINDING PROTEIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.Luteinizing Hormone: A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.Estradiol: The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.Gonadal Steroid Hormones: Steroid hormones produced by the GONADS. They stimulate reproductive organs, germ cell maturation, and the secondary sex characteristics in the males and the females. The major sex steroid hormones include ESTRADIOL; PROGESTERONE; and TESTOSTERONE.Epitestosterone: The 17-alpha isomer of TESTOSTERONE, derived from PREGNENOLONE via the delta5-steroid pathway, and via 5-androstene-3-beta,17-alpha-diol. Epitestosterone acts as an antiandrogen in various target tissues. The ratio between testosterone/epitestosterone is used to monitor anabolic drug abuse.Castration: Surgical removal or artificial destruction of gonads.Androstenedione: A delta-4 C19 steroid that is produced not only in the TESTIS, but also in the OVARY and the ADRENAL CORTEX. Depending on the tissue type, androstenedione can serve as a precursor to TESTOSTERONE as well as ESTRONE and ESTRADIOL.Follicle Stimulating Hormone: A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.Flutamide: An antiandrogen with about the same potency as cyproterone in rodent and canine species.Testosterone Congeners: Steroidal compounds related to TESTOSTERONE, the major mammalian male sex hormone. Testosterone congeners include important testosterone precursors in the biosynthetic pathways, metabolites, derivatives, and synthetic steroids with androgenic activities.Receptors, Androgen: Proteins, generally found in the CYTOPLASM, that specifically bind ANDROGENS and mediate their cellular actions. The complex of the androgen and receptor migrates to the CELL NUCLEUS where it induces transcription of specific segments of DNA.Sexual Maturation: Achievement of full sexual capacity in animals and in humans.Dehydroepiandrosterone: A major C19 steroid produced by the ADRENAL CORTEX. It is also produced in small quantities in the TESTIS and the OVARY. Dehydroepiandrosterone (DHEA) can be converted to TESTOSTERONE; ANDROSTENEDIONE; ESTRADIOL; and ESTRONE. Most of DHEA is sulfated (DEHYDROEPIANDROSTERONE SULFATE) before secretion.3-Oxo-5-alpha-Steroid 4-Dehydrogenase: An enzyme that catalyzes the reduction of TESTOSTERONE to 5-ALPHA DIHYDROTESTOSTERONE.Gonadotropin-Releasing Hormone: A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.Hormone Replacement Therapy: Therapeutic use of hormones to alleviate the effects of hormone deficiency.Organ Size: The measurement of an organ in volume, mass, or heaviness.Drug Implants: Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.Dehydroepiandrosterone Sulfate: The circulating form of a major C19 steroid produced primarily by the ADRENAL CORTEX. DHEA sulfate serves as a precursor for TESTOSTERONE; ANDROSTENEDIONE; ESTRADIOL; and ESTRONE.Spermatogenesis: The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.Sex Characteristics: Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.Sexual Behavior, Animal: Sexual activities of animals.Radioimmunoassay: Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.Androgen Antagonists: Compounds which inhibit or antagonize the biosynthesis or actions of androgens.Chorionic Gonadotropin: A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).Aromatase: An enzyme that catalyzes the desaturation (aromatization) of the ring A of C19 androgens and converts them to C18 estrogens. In this process, the 19-methyl is removed. This enzyme is membrane-bound, located in the endoplasmic reticulum of estrogen-producing cells of ovaries, placenta, testes, adipose, and brain tissues. Aromatase is encoded by the CYP19 gene, and functions in complex with NADPH-FERRIHEMOPROTEIN REDUCTASE in the cytochrome P-450 system.Prostate: A gland in males that surrounds the neck of the URINARY BLADDER and the URETHRA. It secretes a substance that liquefies coagulated semen. It is situated in the pelvic cavity behind the lower part of the PUBIC SYMPHYSIS, above the deep layer of the triangular ligament, and rests upon the RECTUM.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.Libido: The psychic drive or energy associated with sexual instinct in the broad sense (pleasure and love-object seeking). It may also connote the psychic energy associated with instincts in general that motivate behavior.Hirsutism: A condition observed in WOMEN and CHILDREN when there is excess coarse body hair of an adult male distribution pattern, such as facial and chest areas. It is the result of elevated ANDROGENS from the OVARIES, the ADRENAL GLANDS, or exogenous sources. The concept does not include HYPERTRICHOSIS, which is an androgen-independent excessive hair growth.Androstanes: The family of steroids from which the androgens are derived.Virilism: Development of male secondary SEX CHARACTERISTICS in the FEMALE. It is due to the effects of androgenic metabolites of precursors from endogenous or exogenous sources, such as ADRENAL GLANDS or therapeutic drugs.Genitalia, Male: The male reproductive organs. They are divided into the external organs (PENIS; SCROTUM;and URETHRA) and the internal organs (TESTIS; EPIDIDYMIS; VAS DEFERENS; SEMINAL VESICLES; EJACULATORY DUCTS; PROSTATE; and BULBOURETHRAL GLANDS).Cyproterone: An anti-androgen that, in the form of its acetate (CYPROTERONE ACETATE), also has progestational properties. It is used in the treatment of hypersexuality in males, as a palliative in prostatic carcinoma, and, in combination with estrogen, for the therapy of severe acne and hirsutism in females.Sperm Count: A count of SPERM in the ejaculum, expressed as number per milliliter.Gonadotropins, Pituitary: Hormones secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR) that stimulate gonadal functions in both males and females. They include FOLLICLE STIMULATING HORMONE that stimulates germ cell maturation (OOGENESIS; SPERMATOGENESIS), and LUTEINIZING HORMONE that stimulates the production of sex steroids (ESTROGENS; PROGESTERONE; ANDROGENS).Steroids: A group of polycyclic compounds closely related biochemically to TERPENES. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (STEROLS), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. (From Hawley's Condensed Chemical Dictionary, 11th ed)Seminal Vesicles: A saclike, glandular diverticulum on each ductus deferens in male vertebrates. It is united with the excretory duct and serves for temporary storage of semen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Hormones: Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.Androstane-3,17-diol: The unspecified form of the steroid, normally a major metabolite of TESTOSTERONE with androgenic activity. It has been implicated as a regulator of gonadotropin secretion.17-Hydroxysteroid Dehydrogenases: A class of enzymes that catalyzes the oxidation of 17-hydroxysteroids to 17-ketosteroids. EC 1.1.-.Androsterone: A metabolite of TESTOSTERONE or ANDROSTENEDIONE with a 3-alpha-hydroxyl group and without the double bond. The 3-beta hydroxyl isomer is epiandrosterone.Cyproterone Acetate: An agent with anti-androgen and progestational properties. It shows competitive binding with dihydrotestosterone at androgen receptor sites.17-Ketosteroids: Steroids that contain a ketone group at position 17.5-alpha Reductase Inhibitors: Drugs that inhibit 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE. They are commonly used to reduce the production of DIHYDROTESTOSTERONE.17-alpha-Hydroxyprogesterone: A metabolite of PROGESTERONE with a hydroxyl group at the 17-alpha position. It serves as an intermediate in the biosynthesis of HYDROCORTISONE and GONADAL STEROID HORMONES.Contraceptive Agents, Male: Chemical substances or agents with contraceptive activity in males. Use for male contraceptive agents in general or for which there is no specific heading.Cholestenone 5 alpha-Reductase: An oxidoreductase that catalyzes the conversion of 3-oxo-delta4 steroids into their corresponding 5alpha form. It plays an important role in the conversion of TESTOSTERONE into DIHYDROTESTOSTERONE and PROGESTERONE into DIHYDROPROGESTERONE.Hydroxytestosterones: 17 beta-Hydroxy-4-androsten-3-ones. Testosterone derivatives formed by the substitution of one or more hydroxyl groups in any position.Leuprolide: A potent synthetic long-acting agonist of GONADOTROPIN-RELEASING HORMONE that regulates the synthesis and release of pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE.Sertoli Cells: Supporting cells projecting inward from the basement membrane of SEMINIFEROUS TUBULES. They surround and nourish the developing male germ cells and secrete ANDROGEN-BINDING PROTEIN and hormones such as ANTI-MULLERIAN HORMONE. The tight junctions of Sertoli cells with the SPERMATOGONIA and SPERMATOCYTES provide a BLOOD-TESTIS BARRIER.Seminiferous Tubules: The convoluted tubules in the TESTIS where sperm are produced (SPERMATOGENESIS) and conveyed to the RETE TESTIS. Spermatogenic tubules are composed of developing germ cells and the supporting SERTOLI CELLS.Estrogens: Compounds that interact with ESTROGEN RECEPTORS in target tissues to bring about the effects similar to those of ESTRADIOL. Estrogens stimulate the female reproductive organs, and the development of secondary female SEX CHARACTERISTICS. Estrogenic chemicals include natural, synthetic, steroidal, or non-steroidal compounds.Gonadotropins: Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.Estrone: An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from ANDROSTENEDIONE directly, or from TESTOSTERONE via ESTRADIOL. In humans, it is produced primarily by the cyclic ovaries, PLACENTA, and the ADIPOSE TISSUE of men and postmenopausal women.Administration, Cutaneous: The application of suitable drug dosage forms to the skin for either local or systemic effects.Nandrolone: C18 steroid with androgenic and anabolic properties. It is generally prepared from alkyl ethers of ESTRADIOL to resemble TESTOSTERONE but less one carbon at the 19 position.3-Hydroxysteroid Dehydrogenases: Catalyze the oxidation of 3-hydroxysteroids to 3-ketosteroids.Pituitary Gland: A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM.Inhibins: Glycoproteins that inhibit pituitary FOLLICLE STIMULATING HORMONE secretion. Inhibins are secreted by the Sertoli cells of the testes, the granulosa cells of the ovarian follicles, the placenta, and other tissues. Inhibins and ACTIVINS are modulators of FOLLICLE STIMULATING HORMONE secretions; both groups belong to the TGF-beta superfamily, as the TRANSFORMING GROWTH FACTOR BETA. Inhibins consist of a disulfide-linked heterodimer with a unique alpha linked to either a beta A or a beta B subunit to form inhibin A or inhibin B, respectivelySteroid 17-alpha-Hydroxylase: A microsomal cytochrome P450 enzyme that catalyzes the 17-alpha-hydroxylation of progesterone or pregnenolone and subsequent cleavage of the residual two carbons at C17 in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP17 gene, generates precursors for glucocorticoid, androgen, and estrogen synthesis. Defects in CYP17 gene cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL) and abnormal sexual differentiation.Polycystic Ovary Syndrome: A complex disorder characterized by infertility, HIRSUTISM; OBESITY; and various menstrual disturbances such as OLIGOMENORRHEA; AMENORRHEA; ANOVULATION. Polycystic ovary syndrome is usually associated with bilateral enlarged ovaries studded with atretic follicles, not with cysts. The term, polycystic ovary, is misleading.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Prolactin: A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Hyperandrogenism: A condition caused by the excessive secretion of ANDROGENS from the ADRENAL CORTEX; the OVARIES; or the TESTES. The clinical significance in males is negligible. In women, the common manifestations are HIRSUTISM and VIRILISM as seen in patients with POLYCYSTIC OVARY SYNDROME and ADRENOCORTICAL HYPERFUNCTION.Finasteride: An orally active 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE inhibitor. It is used as a surgical alternative for treatment of benign PROSTATIC HYPERPLASIA.Anabolic Agents: These compounds stimulate anabolism and inhibit catabolism. They stimulate the development of muscle mass, strength, and power.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.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Hydrocortisone: The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions.Hydroxyprogesterones: Metabolites or derivatives of PROGESTERONE with hydroxyl group substitution at various sites.Steroid 16-alpha-Hydroxylase: A liver microsomal cytochrome P450 enzyme that catalyzes the 16-alpha-hydroxylation of a broad spectrum of steroids, fatty acids, and xenobiotics in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme is encoded by a number of genes from several CYP2 subfamilies.Cytochrome P-450 Enzyme System: A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.Steroid Hydroxylases: Cytochrome P-450 monooxygenases (MIXED FUNCTION OXYGENASES) that are important in steroid biosynthesis and metabolism.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Azasteroids: Steroidal compounds in which one or more carbon atoms in the steroid ring system have been substituted with nitrogen atoms.Cryptorchidism: A developmental defect in which a TESTIS or both TESTES failed to descend from high in the ABDOMEN to the bottom of the SCROTUM. Testicular descent is essential to normal SPERMATOGENESIS which requires temperature lower than the BODY TEMPERATURE. Cryptorchidism can be subclassified by the location of the maldescended testis.Sex Differentiation: The process in developing sex- or gender-specific tissue, organ, or function after SEX DETERMINATION PROCESSES have set the sex of the GONADS. Major areas of sex differentiation occur in the reproductive tract (GENITALIA) and the brain.Androgen-Insensitivity Syndrome: A disorder of sexual development transmitted as an X-linked recessive trait. These patients have a karyotype of 46,XY with end-organ resistance to androgen due to mutations in the androgen receptor (RECEPTORS, ANDROGEN) gene. Severity of the defect in receptor quantity or quality correlates with their phenotypes. In these genetic males, the phenotypic spectrum ranges from those with normal female external genitalia, through those with genital ambiguity as in Reifenstein Syndrome, to that of a normal male with INFERTILITY.Transsexualism: Severe gender dysphoria, coupled with a persistent desire for the physical characteristics and social roles that connote the opposite biological sex. (APA, DSM-IV, 1994)Ovary: The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.Scrotum: A cutaneous pouch of skin containing the testicles and spermatic cords.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Andropause: An endocrine state in men, characterized by a significant decline in the production of TESTOSTERONE; DEHYDROEPIANDROSTERONE; and other hormones such as HUMAN GROWTH HORMONE. Andropause symptoms are related to the lack of androgens including DEPRESSION, sexual dysfunction, and OSTEOPOROSIS. Andropause may also result from hormonal ablation therapy for malignant diseases.Doping in Sports: Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.Copulation: Sexual union of a male and a female in non-human species.Erectile Dysfunction: The inability in the male to have a PENILE ERECTION due to psychological or organ dysfunction.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Diethylstilbestrol: A synthetic nonsteroidal estrogen used in the treatment of menopausal and postmenopausal disorders. It was also used formerly as a growth promoter in animals. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), diethylstilbestrol has been listed as a known carcinogen. (Merck, 11th ed)Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Prostatic Neoplasms: Tumors or cancer of the PROSTATE.Klinefelter Syndrome: A form of male HYPOGONADISM, characterized by the presence of an extra X CHROMOSOME, small TESTES, seminiferous tubule dysgenesis, elevated levels of GONADOTROPINS, low serum TESTOSTERONE, underdeveloped secondary sex characteristics, and male infertility (INFERTILITY, MALE). Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several karyotype variants include 48,XXYY; 48,XXXY; 49,XXXXY, and mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.).Puberty: A period in the human life in which the development of the hypothalamic-pituitary-gonadal system takes place and reaches full maturity. The onset of synchronized endocrine events in puberty lead to the capacity for reproduction (FERTILITY), development of secondary SEX CHARACTERISTICS, and other changes seen in ADOLESCENT DEVELOPMENT.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Cytochrome P-450 CYP3A: A cytochrome P-450 suptype that has specificity for a broad variety of lipophilic compounds, including STEROIDS; FATTY ACIDS; and XENOBIOTICS. This enzyme has clinical significance due to its ability to metabolize a diverse array of clinically important drugs such as CYCLOSPORINE; VERAPAMIL; and MIDAZOLAM. This enzyme also catalyzes the N-demethylation of ERYTHROMYCIN.Cholesterol Side-Chain Cleavage Enzyme: A mitochondrial cytochrome P450 enzyme that catalyzes the side-chain cleavage of C27 cholesterol to C21 pregnenolone in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11A1 gene, catalyzes the breakage between C20 and C22 which is the initial and rate-limiting step in the biosynthesis of various gonadal and adrenal steroid hormones.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Ovariectomy: The surgical removal of one or both ovaries.Territoriality: Behavior in defense of an area against another individual or individuals primarily of the same species.Hypophysectomy: Surgical removal or destruction of the hypophysis, or pituitary gland. (Dorland, 28th ed)Social Dominance: Social structure of a group as it relates to the relative social rank of dominance status of its members. (APA, Thesaurus of Psychological Index Terms, 8th ed.)Aryl Hydrocarbon Hydroxylases: A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.Aromatase Inhibitors: Compounds that inhibit AROMATASE in order to reduce production of estrogenic steroid hormones.Preoptic Area: Region of hypothalamus between the ANTERIOR COMMISSURE and OPTIC CHIASM.Ketoconazole: Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients.Receptors, LH: Those protein complexes or molecular sites on the surfaces and cytoplasm of gonadal cells that bind luteinizing or chorionic gonadotropic hormones and thereby cause the gonadal cells to synthesize and secrete sex steroids. The hormone-receptor complex is internalized from the plasma membrane and initiates steroid synthesis.Sexual Development: The processes of anatomical and physiological changes related to sexual or reproductive functions during the life span of a human or an animal, from FERTILIZATION to DEATH. These include SEX DETERMINATION PROCESSES; SEX DIFFERENTIATION; SEXUAL MATURATION; and changes during AGING.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.Pregnenolone: A 21-carbon steroid, derived from CHOLESTEROL and found in steroid hormone-producing tissues. Pregnenolone is the precursor to GONADAL STEROID HORMONES and the adrenal CORTICOSTEROIDS.Androgen-Binding Protein: Carrier proteins produced in the Sertoli cells of the testis, secreted into the seminiferous tubules, and transported via the efferent ducts to the epididymis. They participate in the transport of androgens. Androgen-binding protein has the same amino acid sequence as SEX HORMONE-BINDING GLOBULIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.Dibutyl Phthalate: A plasticizer used in most plastics and found in water, air, soil, plants and animals. It may have some adverse effects with long-term exposure.Prenatal Exposure Delayed Effects: The consequences of exposing the FETUS in utero to certain factors, such as NUTRITION PHYSIOLOGICAL PHENOMENA; PHYSIOLOGICAL STRESS; DRUGS; RADIATION; and other physical or chemical factors. These consequences are observed later in the offspring after BIRTH.Antlers: The horn of an animal of the deer family, typically present only in the male. It differs from the HORNS of other animals in being a solid, generally branched bony outgrowth that is shed and renewed annually. The word antler comes from the Latin anteocularis, ante (before) + oculus (eye). (From Webster, 3d ed)Injections, Intramuscular: Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.Penis: The external reproductive organ of males. It is composed of a mass of erectile tissue enclosed in three cylindrical fibrous compartments. Two of the three compartments, the corpus cavernosa, are placed side-by-side along the upper part of the organ. The third compartment below, the corpus spongiosum, houses the urethra.Gonadal Hormones: Hormones produced by the GONADS, including both steroid and peptide hormones. The major steroid hormones include ESTRADIOL and PROGESTERONE from the OVARY, and TESTOSTERONE from the TESTIS. The major peptide hormones include ACTIVINS and INHIBINS.Androstenediol: An intermediate in TESTOSTERONE biosynthesis, found in the TESTIS or the ADRENAL GLANDS. Androstenediol, derived from DEHYDROEPIANDROSTERONE by the reduction of the 17-keto group (17-HYDROXYSTEROID DEHYDROGENASES), is converted to TESTOSTERONE by the oxidation of the 3-beta hydroxyl group to a 3-keto group (3-HYDROXYSTEROID DEHYDROGENASES).Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Hydroxylation: Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)Penile Erection: The state of the PENIS when the erectile tissue becomes filled or swollen (tumid) with BLOOD and causes the penis to become rigid and elevated. It is a complex process involving CENTRAL NERVOUS SYSTEM; PERIPHERAL NERVOUS SYSTEMS; HORMONES; SMOOTH MUSCLES; and vascular functions.Ketosteroids: Steroid derivatives formed by oxidation of a methyl group on the side chain or a methylene group in the ring skeleton to form a ketone.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Desogestrel: A synthetic progestational hormone used often as the progestogenic component of combined oral contraceptive agents.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Saliva: The clear, viscous fluid secreted by the SALIVARY GLANDS and mucous glands of the mouth. It contains MUCINS, water, organic salts, and ptylin.

Changed levels of endogenous sex steroids in women on oral contraceptives. (1/7518)

Serum and urinary levels of unconjugated testosterone, dihydrotestosterone, and oestradiol were measured by specific radioimmunoassays in 10 healthy women in the early follicular phase of their menstrual cycle and in nine healthy women taking oral contraceptives. The contraceptive group had testosterone levels 1-3 times higher and dihydrotestosterone levels two times higher than those in the controls. Serum oestradiol levels in the contraceptive group were much lower than those in the controls and similar to levels in postmenopausal women. The contraceptive group had about twice the urinary excretion of unconjugated (free) testosterone and dihydrotestosterone of the controls, but their excretion of unconjugated oestradiol was 2-7 times lower. The great increase in serum and urinary androgen concentrations, as well as the suppression of oestradiol, may be related to the antiovulatory effect of oral contraceptives.  (+info)

The effects of androgens and antiandrogens on hormone-responsive human breast cancer in long-term tissue culture. (2/7518)

We have examined five human breast cancer cell lines in continuous tissue culture for androgen responsiveness. One of these cell lines shows a 2- to 4-fold stimulation of thymidine incorporation into DNA, apparent as early as 10 hr following androgen addition to cells incubated in serum-free medium. This stimulation is accompanied by an acceleration in cell replication. Antiandrogens [cyproterone acetate (6-chloro-17alpha-acetate-1,2alpha-methylene-4,6-pregnadiene-3,20-dione) and R2956 (17beta-hydroxy-2,2,17alpha-trimethoxyestra-4,9,11-triene-1-one)] inhibit both protein and DNA synthesis below control levels and block androgen-mediated stimulation. Prolonged incubation (greater than 72 hr) in antiandrogen is lethal. The MCF- cell line contains high-affinity receptors for androgenic steroids demonstrable by sucrose density gradients and competitive protein binding analysis. By cross-competition studies, androgen receptors are distinguishable from estrogen receptors also found in this cell line. Concentrations of steroid that saturate androgen receptor sites in vitro are about 1000 times lower than concentrations that maximally stimulate the cells. Changes in quantity and affinity of androgen binding to intact cells at 37 degrees as compared with usual binding techniques using cytosol preparation at 0 degrees do not explain this difference between dissociation of binding and effect. However, this difference can be explained by conversion of [3H]-5alpha-dihydrotestosterone to 5alpha-androstanediol and more polar metabolites at 37 degrees. An examination of incubation media, cytoplasmic extracts and crude nuclear pellets reveals probable conversion of [3H]testosterone to [3H]-5alpha-dihydrotestosterone. Our data provide compelling evidence that some human breast cancer, at least in vitro, may be androgen dependent.  (+info)

Effect of sex difference on the in vitro and in vivo metabolism of aflatoxin B1 by the rat. (3/7518)

Hepatic microsome-catalyzed metabolism of aflatoxin B1 (AFB1) to aflatoxin M1 and aflatoxin Q1 and the "metabolic activation" of AFB1 to DNA-alylating metabolite(s) were studied in normal male and female Sprague-Dawley rats, in gonadectomized animals, and in castrated males and normal females treated with testosterone. Microsomes from male animals formed 2 to 5 times more aflatoxin M1, aflatoxin Q1, and DNA-alkylating metabolite(s) than those from females. Castration reduced the metabolism of AFB1 by the microsomes from males by about 50%, whereas ovariectomy had no significant effect on AFB1 metabolism by the microsomes from females. Testosterone treatment (4 mg/rat, 3 times/week for about 6 weeks) of castrated immature males and immature females enhanced the metabolism of AFB1 by their microsomes. A sex difference in the metabolism of AFB1 by liver microsomes was also seen in other strains of rats tested: Wistar, Long-Evans, and Fischer. The activity of kidney microsomes for metabolic activation was 1 to 4% that of the liver activity and was generally lower in microsomes from male rats as compared to those from female rats of Sprague-Dawley, Wistar, and Long-Evans strains. The in vitro results obtained with hepatic microsomes correlated well with the in vivo metabolism of AFB1, in that more AFB1 became bound in vivo to hepatic DNA isolated from male rats and from a female rat treated with testosterone than that isolated from control female rats. These data suggest that the differences in hepatic AFB1 metabolism may be the underlying cause of the sex difference in toxicity and carcinogenicity of AFB1 observed in rats.  (+info)

Sex differences in the effects of early neocortical injury on neuronal size distribution of the medial geniculate nucleus in the rat are mediated by perinatal gonadal steroids. (4/7518)

Freezing injury to the cortical plate of rats induces cerebrocortical microgyria and, in males but not females, a shift toward greater numbers of small neurons in the medial geniculate nucleus (MGN). The purpose of the current study was to examine a hormonal basis for this sex difference. Cross-sectional neuronal areas of the MGN were measured in male rats, untreated female rats and female rats treated perinatally with testosterone propionate, all of which had received either neonatal cortical freezing or sham injury. Both male and androgenized female rats with microgyria had significantly smaller MGN neurons when compared to their sham-operated counterparts, whereas untreated females with microgyria did not. These differences were also reflected in MGN neuronal size distribution: both male and androgenized female rats with microgyria had more small and fewer large neurons in their MGN in comparison to shams, while there was no difference in MGN neuronal size distribution between lesioned and sham females. These findings suggest that perinatal gonadal steroids mediate the sex difference in thalamic response to induction of microgyria in the rat cortex.  (+info)

Prolactin replacement fails to inhibit reactivation of gonadotropin secretion in rams treated with melatonin under long days. (5/7518)

This study tested the hypothesis that prolactin (PRL) inhibits gonadotropin secretion in rams maintained under long days and that treatment with melatonin (s.c. continuous-release implant; MEL-IMP) reactivates the reproductive axis by suppressing PRL secretion. Adult Soay rams were maintained under long days (16L:8D) and received 1) no further treatment (control, C); 2) MEL-IMP for 16 wk and injections of saline/vehicle for the first 8 wk (M); 3) MEL-IMP for 16 wk and exogenous PRL (s.c. 5 mg ovine PRL 3x daily) for the first 8 wk (M+P). The treatment with melatonin induced a rapid increase in the blood concentrations of FSH and testosterone, rapid growth of the testes, an increase in the frequency of LH pulses, and a decrease in the LH response to N-methyl-D,L-aspartic acid. The concomitant treatment with exogenous PRL had no effect on these reproductive responses but caused a significant delay in the timing of the sexual skin color and growth of the winter pelage. These results do not support the hypothesis and suggest that PRL at physiological long-day concentrations, while being totally ineffective as an inhibitor of gonadotropin secretion, acts in the peripheral tissues and skin to maintain summer characteristics.  (+info)

Effects of spinal cord injury on spermatogenesis and the expression of messenger ribonucleic acid for Sertoli cell proteins in rat Sertoli cell-enriched testes. (6/7518)

The study was an examination of the effects of spinal cord injury (SCI) on spermatogenesis and Sertoli cell functions in adult rats with Sertoli cell-enriched (SCE) testes. The effects of SCI on the seminiferous epithelium were characterized by abnormalities in the remaining spermatogenic cells during the first month after SCI. Three days after SCI, serum testosterone levels were 80% lower, while serum FSH and LH levels were 25% and 50% higher, respectively, than those of sham control SCE rats. At this time, the levels of mRNA for androgen receptor (AR), FSH receptor (FSH-R), and androgen-binding protein (ABP) were normal whereas those for transferrin (Trf) had decreased by 40%. Thereafter, serum testosterone levels increased, but they remained lower than those of the sham control rats 28 days after SCI; and serum FSH and LH levels returned to normal. The levels of mRNA for AR, ABP, and Trf exhibited a biphasic increase 7 days after SCI and remained elevated 28 days after SCI. FSH-R mRNA levels were also elevated 90 days after SCI. Unexpectedly, active spermatogenesis, including qualitatively complete spermatogenesis, persisted in > 40% of the tubules 90 days after SCI. These results suggest that the stem cells and/or undifferentiated spermatogonia in SCE testes are less susceptible to the deleterious effects of SCI than the normal testes and that they were able to proliferate and differentiate after SCI. The presence of elevated levels of mRNA for Sertoli cell FSH-R and AR, as well as of that for the Sertoli cell proteins, in the SCE testes during the chronic stage of SCI suggests a modification of Sertoli cell physiology. Such changes in Sertoli cell functions may provide a beneficial environment for the proliferation of the stem cells and differentiation of postmeiotic cells, thus resulting in the persistence of spermatogenesis in these testes.  (+info)

Sex steroid and prolactin profiles in male American black bears (Ursus americanus) during denning. (7/7518)

Serum sex steroid and prolactin profiles were examined in the male American black bear, Ursus americanus during denning. Sera collected in December and the following March from 8 denning male black bears in Minnesota, U.S.A. were assayed for testosterone, estradiol-17 beta and prolactin. Eight bears were confirmed to be the denning mode based on a serum urea to creatinine ratio less than 10. Serum testosterone concentrations tended to increase from December to the subsequent March whereas serum estradiol-17 beta concentrations tended to decrease during this period. There were few changes in serum prolactin concentrations between December and March. These findings suggest that spermatogenesis and testicular steroidogenesis initiated during denning may be influenced by changes in serum sex steroid concentrations in the American black bear.  (+info)

BDNF mediates the effects of testosterone on the survival of new neurons in an adult brain. (8/7518)

New neurons are incorporated into the high vocal center (HVC), a nucleus of the adult canary (Serinus canaria) brain that plays a critical role in the acquisition and production of learned song. Recruitment of new neurons in the HVC is seasonally regulated and depends upon testosterone levels. We show here that brain-derived neurotrophic factor (BDNF) is present in the HVC of adult males but is not detectable in that of females, though the HVC of both sexes has BDNF receptors (TrkB). Testosterone treatment increases the levels of BDNF protein in the female HVC, and BDNF infused into the HVC of adult females triples the number of new neurons. Infusion of a neutralizing antibody to BDNF blocks the testosterone-induced increase in new neurons. Our results demonstrate that BDNF is involved in the regulation of neuronal replacement in the adult canary brain and suggest that the effects of testosterone are mediated through BDNF.  (+info)

  • As men age, their sexual function, vitality and strength can decline, but researchers had not yet established whether testosterone treatment is actually beneficial. (ufl.edu)
  • The researchers found that the treatment increased the blood testosterone level from moderately low to mid-normal in men ages 19-40 and improved all aspects of sexual function, including sexual activity, sexual desire and the ability to get an erection. (ufl.edu)
  • Researchers screened 51,085 men and found 790 who had a sufficiently low testosterone level to be part of the study. (ufl.edu)
  • Researchers at the Perelman School of Medicine at the University of Pennsylvania designed and coordinated the Testosterone Trials, a series of studies at 12 academic medical centers across the United States. (cnn.com)
  • The researchers randomly assigned half the participants to use a daily testosterone gel and the other half a placebo gel for one year. (cnn.com)
  • A team of international researchers - led by Carlos Martinez of the Institute for Epidemiology, Statistics and Informatics GmbH in Frankfurt, Germany - decided to investigate the risk of VTE associated with testosterone treatment in men, with a focus particularly on the timing of the risk. (medicalnewstoday.com)
  • After adjusting for comorbidities and other influencing factors, researchers estimated the rate ratios of VTE in association with current testosterone treatment and compared it with no treatment. (medicalnewstoday.com)
  • In the first 6 months of testosterone treatment, researchers found a 63 percent increased risk of VTE. (medicalnewstoday.com)
  • Researchers from the University of Bonn gave 46 people testosterone gel and 45 people a placebo. (hindustantimes.com)
  • After paying out the participants, the researchers found that men who received the testosterone gel self-reported their numbers more honestly, said researchers. (hindustantimes.com)
  • Researchers from Wayne State University also compared two groups of men competing to win the attention of an attractive woman and found that men with lower testosterone didn't even stand a chance. (hindustantimes.com)
  • To test this hypothesis, the researchers had 54 female volunteers ingest a liquid solution several hours before participating in an investing game - some volunteers received a placebo solution, while others received a solution with added testosterone. (psychcentral.com)
  • Just as the researchers predicted, testosterone seemed to promote antisocial behavior in response to a potential threat - in this case, a threat to financial resources. (psychcentral.com)
  • So it's unclear what the findings mean for younger, healthier men who take testosterone, researchers said. (reuters.com)
  • When the researchers took into account the extent of men's initial artery blockages, they calculated that using testosterone was tied to a 29-percent higher risk of heart attack, stroke or death. (reuters.com)
  • In fact, men who started using testosterone initially had fewer health problems than those who didn't, the researchers wrote Tuesday in the Journal of the American Medical Association. (reuters.com)
  • No, it's testosterone, the essence of manhood, that some researchers say is directly responsible for causing financial turmoil, and that it needs to be curtailed. (naturalnews.com)
  • Although men in the testosterone group did report a slight improvement in their satisfaction with intercourse, the effect was small and could have been due to chance, the researchers said. (livescience.com)
  • German researchers found that when they administered testosterone to a group of 46 men, they cheated less on a dice game than 45 men that were given placebo. (ibtimes.com)
  • The researchers saw that in general, subjects that received testosterone reported lower numbers and received lower payoffs than the subjects in the control group. (ibtimes.com)
  • Researchers are uncovering more and more about testosterone and how it connects to men's health. (feedburner.com)
  • The researchers found the usual decline in testosterone with age. (psychcentral.com)
  • Use of testosterone can help increase sexual desire in menopausal women with hypoactive sexual desire disorder (HSDD), particularly in those patients who have had surgical removal of their ovaries. (medscape.com)
  • To answer her first question, testosterone is indeed present in women, produced primarily in their ovaries and adrenal glands. (americanscientist.org)
  • Young women produce most of their testosterone in the ovaries. (marksdailyapple.com)
  • Women need testosterone too and the ovaries and adrenal glands produce it in low amounts. (giantmicrobes.com)
  • Dr. Catherine Cohan, assistant professor of human development and family studies, says, "It's not necessarily the case that higher testosterone is all bad. (scienceblog.com)
  • Men who have low testosterone talk more about their energy, feeling mental and physically better when they have a higher testosterone," says Goodman. (cosmopolitan.com)
  • Take testosterone at around the same times every day. (medlineplus.gov)
  • Take testosterone exactly as directed. (medlineplus.gov)
  • Your doctor will probably tell you that you should not take testosterone. (medlineplus.gov)
  • NEW YORK (Reuters Health) - Older men who take testosterone are more likely to have a heart attack or stroke or die over the next few years, new research indicates. (reuters.com)
  • Final however not least, it's all the time extremely beneficial that you've a quick speak with your family physician or general practitioner before beginning to take testosterone boosters. (dailystrength.org)
  • My body doesn't produce Testosterone anymore because of Hemochromatosis, which is a blood disease which produces too much iron in my blood. (healthboards.com)
  • In addition, celery is an excellent source of vitamin K, which might actually boost a man's ability to produce testosterone. (livestrong.com)
  • This is because body fat converts testoterone to estradiol, which potentially reduces your body's ability to produce testosterone. (livestrong.com)
  • Your ability to produce testosterone depends heavily upon your dietary fat intake. (livestrong.com)
  • A new testosterone gel, AndroGel 1% was released in August 2000 is now available pharmaceutical. (earthlink.net)
  • If you have lost a family member to a heart attack or other cardiac incident and believe testosterone therapies such as Androgel or Testim may have been the cause, contact testosterone lawyers handling national claims to learn about your legal rights. (prweb.com)
  • That drove sales of topical testosterone drugs like AndroGel and Axiron $2 billion a year, with AbbVie taking more than 65% of the market, according to market researcher IMS Health. (forbes.com)
  • The new gel approved this past summer, Androgel by Unimed Pharmaceuticals Inc., is the easiest way to supplement testosterone as it is a clear gel that is rubbed into the skin once a day. (thebody.com)
  • Some patients have already filed a testosterone lawsuit in federal court alleging AndroGel caused heart attack or stroke without warning. (prweb.com)
  • If the serum testosterone concentration is below the normal range, the daily AndroGel dose may be increased from 5 g to 7.5 g and from 7.5 g to 10 g for adult males as instructed by the physician. (nih.gov)
  • If the serum testosterone concentration exceeds the normal range, the daily AndroGel dose may be decreased. (nih.gov)
  • 3 1/2 years of depression after surgery prior to Hypogonadizm DX, Testosterone Theropy (Testim Gel)since 12/06 but switched to a higher dose of (Androgel) 6/08. (healingwell.com)
  • Both free and albumin-bound testosterone are biologically active, and together are referred to as the bioavailable fraction. (questdiagnostics.com)
  • T pellets ( Testopel ) are used for long term T replacement in men and can be inserted beneath the skin of the stomach to deliver testosterone (T) over a 3 month period. (earthlink.net)
  • Your doctor may need to perform a digital rectal exam to check your prostate gland at least once a year while you are receiving testosterone replacement (more frequently than this if you are elderly or have risk factors for prostate cancer). (netdoctor.co.uk)
  • Each plaintiff's case addresses only one of these defendants, yet the claims against them - specifically that testosterone replacement therapies have allegedly caused patients to have heart attacks and strokes - are common across every one of these testosterone lawsuits, according to the official court documents," explains Jim Onder of the Onder Law Firm. (prweb.com)
  • Plaintiffs in a multidistrict litigation over testosterone replacement drugs on Monday agreed to dismiss remaining cases against Pfizer Inc, following a federal appeals court ruling in January that claims against the company were preempted. (reuters.com)
  • The decision allows Pfizer to fully escape the litigation in which plaintiffs claim several companies failed to warn of the risks of strokes and heart attacks connected to the use of their testosterone replacement products. (reuters.com)
  • Research is inconclusive regarding the role of testosterone replacement in the treatment of erectile dysfunction. (selfgrowth.com)
  • I'd like to point out many of the benefits of testosterone replacement in this article so that people suffering from loss of testosterone can decide if they want to proceed with a testosterone treatment. (infobarrel.com)
  • Many men describe the difference in their quality of life before and after beginning a testosterone replacement program as night and day. (infobarrel.com)
  • What are the delivery systems now for testosterone replacement? (selfgrowth.com)
  • There are several means of testosterone replacement theropy such as gels or shots but most doctors don't like prescribing it for anyone with a history of prostate cancer. (healingwell.com)
  • In response to this, many psychiatrists, who are unfamiliar with testosterone replacement research, will actually INCREASE the patient's antidepressants causing the symptoms to become even more pronounced. (infobarrel.com)
  • The subjects were randomized into two groups: one that applied a daily testosterone gel and the other a daily placebo gel, for one year. (ufl.edu)
  • Across the three trials, adverse events including heart attack, stroke, other cardiovascular events and prostate conditions were similar in men who received testosterone and those who received a placebo. (ufl.edu)
  • Yet the number of cardiovascular events, such as heart attacks, was similar for the men treated with testosterone and those using placebo. (cnn.com)
  • Participants who received the placebo, on the other hand, were more trusting investors, choosing to invest about €3.20 more than those who received testosterone. (psychcentral.com)
  • In this case, participants given testosterone chose to give more money back to the investor than participants who had been given a placebo. (psychcentral.com)
  • The following experiment tests this possibility in a placebo-controlled, within-subjects design involving the administration of testosterone to 24 female subjects. (pnas.org)
  • A phase II trial lasting 84 days reported more orgasms with nasal testosterone than with placebo: 2.3 versus 1.7. (medpagetoday.com)
  • And although testosterone shots, pellets and gels are effective, they are not tolerable or appropriate for many patients, such as men trying to conceive, and are certainly less convenient than making your own testosterone. (news-medical.net)
  • Professor Davis, who is president of the International Menopause Society , says because of possible adverse effects from oral testosterone, non-oral formulations, delivered through gels or patches into the skin, are preferred for women. (afr.com)
  • Q. Will the use of testosterone cause a female to exhibit signs that are typical of males? (earthlink.net)
  • The close link between aggression and testosterone is not surprising, given that males of many species fight over access to fertile females, but the connection is complex. (britannica.com)
  • To date, psychologist James McBride Dabbs ' Heroes, Rogues, and Lovers (2000) is the best book to investigate not simply the physical effects of high testosterone in males, but its mental and emotional ramifications as well. (psychologytoday.com)
  • Dose adjustment for adult males: If serum testosterone level is below the normal range, adjust dose from 5 g to 7.5 g and from 7.5 g to 10 g ( 2.3 ). (nih.gov)
  • Resting testosterone values for mature males range from 14.0 to 28.0 nmol/L (Kraemer, 1988). (exrx.net)
  • In fact," Eisenberg says, "it's been studied as a method of birth control , because 90% of men can drop their sperm counts to zero while on testosterone . (webmd.com)
  • Testosterone plays an important role in making sperm. (webmd.com)
  • Eisenberg describes the relationship between testosterone and sperm production as part of a "feedback loop. (webmd.com)
  • You want to increase the patient's own testosterone production in order to get an appropriate sperm sample for pregnancy ," says Mezitis, who practices at Lenox Hill Hospital in New York City. (webmd.com)
  • When testosterone comes from the outside, it suppresses the body's production of sperm. (webmd.com)
  • If his sperm count is low, the next step is to measure his testosterone. (webmd.com)
  • During adult life, testosterone is essential for the production of sperm, the maintenance of sex drive, erectile potency, and the functioning of the prostate gland and other reproductive structures. (netdoctor.co.uk)
  • Testosterone also contributes to muscle strength , bone strength and density , sense of well being , red blood cell mass , adequate sperm count, sexual performance and penis growth during puberty . (everything2.com)
  • Beyond tribulus (Tribulus terrestris L.): The effects of phytotherapics on testosterone , sperm and prostate parameters. (nih.gov)
  • In men, sperm production is guided by testosterone. (healthline.com)
  • Too little testosterone results in low sperm count. (healthline.com)
  • Testosterone plays a role in the production of semen , which is the milky fluid that aids in the motility of sperm. (selfgrowth.com)
  • You need testosterone to make sperm, and if you have a very low testosterone, you might have a decline in the quality of sperm and number of sperm, says Streicher. (cosmopolitan.com)
  • But, believe it or not, men with extremely low testosterone can still produce normal sperm. (cosmopolitan.com)
  • However, the possible benefits of taking testosterone need to be in a balance with the higher risks of cardiovascular events. (medicalnewstoday.com)
  • The brain's hypothalamus and pituitary gland control testosterone production. (giantmicrobes.com)
  • Because low testosterone may be an indicator for an underlying problem, like a problem with the pituitary gland, liver disease, an inherited disease, or Addison's disease, your doctor may want to test you for an underlying problem if you have low testosterone. (wikihow.com)
  • These include baldness, prostate enlargement, shrinking of testicles, increased acne and loss of sex drive with moodiness and emotionality.Testosterone USP is a white odorless powder which dissolves in alcohol or organic solvents. (earthlink.net)
  • In men, testosterone is produced by the testicles with a small amount made in the adrenal glands. (giantmicrobes.com)
  • The patient could consider trying a lower dose (and/or application frequency) of topical testosterone. (medscape.com)
  • If your testosterone buccal system does not stick or falls off within 8 hours after you apply it, replace it with a new system immediately and apply your next dose at the regularly scheduled time. (medlineplus.gov)
  • Doctors should also ensure the patients are being prescribed the lowest dose of opioids, including methadone, for effective treatment to minimize testosterone suppression," she says in a news release. (medicinenet.com)
  • The article that I think I remember (inserting aging joke of choice here) used relatively high-dose testosterone given intramuscularly once a week. (exrx.net)
  • Although less information is available regarding non-sexuality quality-of-life enhancements with use of testosterone, anecdotal experience suggests some women will experience the improved energy, as noted by this 60-year-old surgically castrate woman. (medscape.com)
  • The 2007 study suggests that although poor health in general is associated with a drop in testosterone , this generational decline cannot be fully explained by obesity, depression, or diabetes. (huffingtonpost.com)
  • New research suggests testosterone can promote generosity, but only when there is no threat of competition. (psychcentral.com)
  • One study suggests that testosterone affects activity in the orbitofrontal cortex, a part of the brain thought to be involved in deception. (ibtimes.com)
  • Although vitamin K primarily helps your blood to clot, a study published in "Food and Function" in 2011 suggests that the amount of vitamin K in a man's body might affect testosterone production. (livestrong.com)
  • Testosterone is related to assertiveness which can be good or bad depending on whether it is manifested as either aggression or being helping and outgoing. (scienceblog.com)
  • Castration has been found to reduce aggression dramatically, while experimental reinstatement of testosterone-for instance, through injection into the blood-restores aggression. (britannica.com)
  • In addition, testosterone of nongonadal origin (i.e., produced by the adrenal gland ) may be important in aggression outside the breeding season, as in the case of birds such as the song sparrow that maintain nonbreeding territories in the winter. (britannica.com)
  • Unlike non-human animals, where a direct connection between testosterone and aggression has been repeatedly demonstrated, in humans the correlation between high-T and aggression, though positive, is only weakly so. (psychologytoday.com)
  • It s true that a lack of testosterone translates to a lack of body hair, but generally speaking, a guy isn t bald because he s low on testosterone, nor is he a hairy beast because he he s full of it. (cosmopolitan.com)
  • The literature supports a modulating role of testosterone on erectile function. (cmaj.ca)
  • As interesting as this subject was, the article left me curious about the role of testosterone in females. (americanscientist.org)
  • The issue is less of problem in Europe, but prescriptions for testosterone have also increased there, by 30% in the United Kingdom, for example. (medscape.com)
  • Prescriptions for testosterone nearly doubled in the three years ending in 2013, to 2.3 million, according to the FDA. (forbes.com)
  • Doctors around the world have written a surprising number of prescriptions for testosterone treatment in recent years. (scientificamerican.com)
  • If confirmed, the 2011 ratio could mean that perhaps two million older men in the U.S. have been given prescriptions for testosterone. (scientificamerican.com)
  • There's just that niggling, pervasive stigma of testosterone as the sole hormonal realm of big burly men with bulging muscles, and I guess it's hard to shake, even for my enlightened readership. (marksdailyapple.com)
  • You can want it all you want, but without the right hormonal balance, which includes plenty of testosterone for men and women, you're not going to want it. (marksdailyapple.com)
  • In conclusion, our data provide unique insights into the hormonal regulation of human sociality by showing that testosterone downregulates interpersonal trust in an adaptive manner. (pnas.org)