Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042755 (masculinization)
 2,562 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Physiological and pathological processes as well as iatrogenic interventions may result in androgen deficiency compared with levels in young healthy women. Whether relative androgen deficiency results in a clinical syndrome similar to that reported in men, including osteopenia, increased fat mass, decreased libido, and diminished quality of life, has not been definitively established. However, preliminary data in postmenopausal women suggest that physiological androgen replacement therapy, which involves substantially lower doses than those used in men, may result in increased bone mineral density, increased libido, and improved quality of life. The safety of androgen preparations that result in supraphysiological levels has not been established in women and would be expected to result in hirsutism, acne, and virilization with chronic use. Androgen preparations that avoid liver metabolism and result in physiological serum androgen levels in women with androgen deficiency are not currently available, but are in development. Therefore, although widespread screening and hormone replacement for androgen deficiency cannot be recommended yet, increasing interest in this topic makes consideration of the available data important.
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PMID:Androgen deficiency in women. 1139 29

The androgen receptor (AR) is the key regulatory element of androgen signaling in the cell. It mediates action of androgens and is therefore essential for growth, function and differentiation of the human male urogenital tract. Genetic alterations in the AR gene may cause impaired development resulting in androgen insensitivity syndromes (AIS) or in neurodegenerative diseases like Kennedy syndrome. Besides the crucial role in the process of virilization during embryogenesis and puberty, the AR also plays an important role in the adult man as the intracellular mediator of androgen action. Androgen withdrawal and/or AR blockade is the main choice of treatment of nonorgan-confined prostate cancer. Unfortunately, this treatment is only palliative and a majority of these tumors recur and progress to an androgen-independent and therapy-resistant stage. Recent findings gave new insight into the molecular structure and function of the AR and improved our understanding about prostate cancer progression, consequently resulting in the development of novel treatments. It has become evident that the AR is a nuclear transcription factor that can be activated ligand-dependently by androgens as well as ligand-independently by other hormones and various growth factors, respectively. Moreover, it was shown that the interaction of the AR with other proteins of the intracellular signal transduction cascade may promote prostate tumor growth. This review will summarize the most important findings about the AR and the androgen signaling pathway to improve the understanding of prostate diseases and novel treatment strategies that may be useful in the clinic.
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PMID:Molecular biology of the androgen receptor: from molecular understanding to the clinic. 1168 38

The mechanisms of sexual differentiation of the brain by sex steroids seem to be conserved throughout the mammalian species, although there may be some species differences. In rats, sex-dependent differentiation of the brain occurs in a sex steroid-dependent manner during the perinatal period known as the critical period. Androgen exposure during the perinatal period results in the development of structural and functional sexually dimorphic characteristics in the brain; the absence of testicular androgen leads the central nervous system to develop passively in a primarily female fashion, while the presence of androgen induces the masculinization of the brain. We attempted to characterize sex steroid-inducible genes that are involved in the sexually dimorphic function of the brain. Following the cDNA subtraction between hypothalami of 5-day-old intact and neonatally androgenized female rats, a granulin (grn) precursor gene was identified. The grn gene encodes a 6-kDa polypeptide known as a growth modulating factor of epithelial cells in vitro. Exogenous estrogen, as well as androgen, induced grn gene expression in the neonatal hypothalamus. In the brain of a 5-day-old male rat, grn mRNA was expressed in the ventromedial hypothalamic nucleus and the arcuate nucleus of the hypothalamus. Throughout the critical period for sexual differentiation of the brain, grn gene expression remained high in males, while in females it gradually decreased. Antisense oligodeoxynucleotide (ODN) complementary to grn mRNA was synthesized and infused into the third ventricle of male rats at 2 days of age. Two different control treatments were used; the first consisted of a control sequence ODN that had virtually no homology to known mRNAs, and the second consisted of vehicle alone. After maturation, the subject animals that were treated with antisense ODN of grn displayed significantly lower scores than the control males in various parameters assessing sexual behavior, i.e., mount, intromission, and ejaculation. The present results suggest that the grn gene, the expression of which is induced by sex steroids in the neonatal hypothalamus, plays a crucial role in the functional masculinization of the rat brain.
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PMID:Granulin precursor gene: a sex steroid-inducible gene involved in sexual differentiation of the rat brain. 1182 61

The rapid onset of virilization in a post-menopausal woman is usually the result of androgen secretion from a tumour of adrenal or ovarian origin. Androgen secreting neoplasms of the ovary are rare and usually show autonomous secretion. Rarely, these may be driven by the high levels of gonadotrophins seen in the post-menopausal state. We describe the case of a 67-year-old woman with high serum testosterone and estradiol in association with the high gonadotrophin levels usually associated with the post-menopausal state. All hormonal parameters showed a significant suppression over 12 h with administration of the GnRH antagonist, cetrorelix. This observation implies that excess hormone synthesis was of ovarian origin and was gonadotrophin driven. Localization of the tumour was not possible by conventional ultrasound or computerized tomography scanning, but was achieved by venous sampling. Complete cure was achieved by total abdominal hysterectomy and bilateral salpingo-oophorectomy, with restoration of the endocrine profile to that expected for a post-menopausal woman. Rapidly acting GnRH antagonists, such as cetrorelix, offer a safe and useful diagnostic and therapeutic option in the management of ovarian steroid-secreting tumours, which show gonadotrophin dependency.
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PMID:An unusual steroid-producing ovarian tumour: case report. 1204 63

Androgen physiology differs from that of other steroid hormones in two major regards. First, testosterone, the predominant circulating testicular androgen, is both an active hormone and a prohormone for the formation of a more active androgen, the 5alpha-reduced steroid dihydrotestosterone. Genetic evidence indicates that testosterone and dihydrotestosterone work via a common intracellular receptor, and studies involving in vitro reporter gene assays and intact mice in which both steroid 5alpha-reductase isoenzymes have been disrupted by homologous recombination indicate that dihydrotestosterone acts during embryonic life to amplify hormonal signals that can be mediated by testosterone at higher concentrations. However, in post-embryonic life dihydrotestosterone plays unique roles that have not been elucidated. Studies of other 5alpha-reduced steroids, including the plant hormone brassinolide, the hog pheromones androstanol and androstenol, and 5alpha-dihydroprogesterone (in horses and elephants) indicate that this reaction serves different functions in different systems. Second, during embryonic life androgen causes the formation of the male urogenital tract and hence is responsible for development of the tissues that serve as the major sites of androgen action in postnatal life. It has been generally assumed that androgens virilize the male fetus by the same mechanisms as in the adult, namely by the conversion of circulating testosterone to dihydrotestosterone in target tissues. However, in marsupial mammals there is no sexual dimorphism in the levels of testosterone or dihydrotestosterone at the time the male phenotype forms, and in the pouch young of one marsupial, the tammar wallaby, the testes secrete another 5alpha-reduced steroid, 5alpha-androstane-3alpha, 17beta-diol (5alpha-adiol), into plasma. The administration of 5alpha-adiol to female pouch young causes profound virilization of the urogenital sinus and external genitalia, but within target tissues 5alpha-adiol appears to work after oxidation to dihydrotestosterone. Thus, two separate mechanisms evolved for the formation of dihydrotestosterone in target tissues. 5alpha-adiol is the predominant androgen in neonatal testes in several placental mammals, but it is unclear whether it plays a similar role in other mammalian species.
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PMID:Androgen physiology: unsolved problems at the millennium. 1257 8

Androgen and progesterone receptors (AR and PR) are two determining factors in gonadal differentiation that are highly expressed in developing and mature gonads. Loss of AR results in XY sex reversal and mutations causing reduced AR activity lead to varying degrees of defects in masculinization. Female PR knockout mice are infertile due to ovarian defects. While much has been discovered about positive regulation of these receptors by coactivators little is known about repression of the transcriptional activity of AR and PR in the presence of agonists. In this study we assessed the effect of SMRT and DAX-1 on AR and PR activity in the presence of both agonists and partial antagonists. We show that SMRT and DAX-1 repress agonist-dependent activity of both receptors, and the mechanism of repression includes disruption of the receptor dimer interactions rather than recruitment of histone deacetylases. We demonstrate that endogenous agonist-bound PR and DAX-1 in T47D breast cancer cells and endogenous AR and DAX-1 in LNCaP prostate cancer cells can be coimmunoprecipitated suggesting that the interaction is physiological. Surprisingly, although DAX-1 represses partial antagonist activity of AR, it was ineffective in repressing partial antagonist induced activity of PR. In contrast to most reported repressors, the expression of DAX-1 is restricted. We found that although DAX-1 is expressed in normal human prostate, its expression is strongly reduced in benign prostatic hyperplasia suggesting that DAX-1 plays a role in limiting AR activity in prostate.
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PMID:Repressors of androgen and progesterone receptor action. 1277 Nov 31

Yearling rhesus monkey females interact more with infants than do males. However, the continuity of this sex difference throughout the juvenile period is unknown. Human females display similar sexually differentiated interest in infants, and studies of girls with congenital adrenal hyperplasia suggest that this sex difference may be modulated by prenatal androgen exposure. We investigated infant interest in 1- to 3-year-old juvenile rhesus monkeys. Hormonal influences on this behavior were investigated by treating pregnant females with an androgen-receptor blocker (flutamide), testosterone enanthate, or vehicle, early or late in gestation. Subjects were reared in their well-established natal groups, composed of species-typical matrilineal social structures, including members of all ages. Yearling control females interacted with infants more than did yearling control males. At 2 and 3 years of age, the magnitude of the sex difference in interactions with infants increased markedly, producing effect sizes of more than 2.5 standard deviations. These effects are larger than those reported in humans. Androgen treatment did not affect male or female interactions with infants, but late gestation flutamide masculinized aspects of females' interest in infants. Although early flutamide prevented complete masculinization of male genitalia, this treatment was not accompanied by any alterations in the masculine pattern of infant interest. We found no evidence that the robust juvenile sex difference in frequency of infant interactions results from socialization. However, it was largely unaffected by our hormone manipulations. Whether this reflects characteristics of our specific treatments or is evidence of nonhormonal influences on infant interest remains unanswered.
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PMID:Sex differences in interest in infants in juvenile rhesus monkeys: relationship to prenatal androgen. 1279 75

There are many treatment options for female sexual dysfunction (FSD), with the optimal therapy depending on the etiology of the problem. The cause of sexual dysfunction is multifactorial and may include psychological problems such as depression or anxiety disorders, conflict within the relationship, partner performance and technique, issues relating to prior abuse, medical illness, medications, fatigue, stress, or gynecological problems that make sexual activity uncomfortable. The role of low androgen concentrations in FSD is gaining increasing attention. Available therapeutic options include adjusting medications, counseling, treating depression or anxiety, reducing stress and fatigue, sex therapy, devices, estrogen therapy for genitourinary atrophy, and possibly vasoactive substances. Although no androgen therapies are currently approved by the Food and Drug Administration for FSD, they are being used in clinical practice, and early clinical trial results suggest that they may be both effective and safe in the treatment of FSD, specifically low libido. Androgen therapy should be considered primarily in women who have a physiological reason for reduced androgen concentrations, including aging, hypopituitarism, oophorectomy, or adrenal insufficiency. Products in use include oral methyltestosterone and dehydroepiandrosterone, topical testosterone ointment, and testosterone implants and injections. Products available for men, including skin patches and gels, are currently being studied at doses appropriate for women. Possible risks include hirsutism, acne, liver dysfunction, lowering of the voice, adverse lipid changes, virilization of a female fetus, and, as androgens are aromatized to estrogens, potentially the risks of estrogen therapy.
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PMID:The role of androgens in female sexual dysfunction. 1506 34

Granulosa cell tumors account for approximately 1-2% of all ovarian tumors. There are two types: adult granulosa cell tumor and juvenile granulosa cell tumor. Juvenile granulosa cell tumors constitute 5% of this histological subtype, and the prognosis is good because the majority present as Stage I tumors. The treatment can consist of conservative surgery. Androgen production is rare and produces virilization in women. These tumors are usually solid or predominantly solid. We describe the case of a 13-year-old girl with androgenic manifestations and increased abdominal size. Her plasma testosterone level was elevated. A left adnexal cyst (14.4 x 9.1 x 9.7 cm) was revealed at pelvic ultrasonography. The patient underwent an exploratory laparotomy, revealing a left ovarian cystic tumor. Diagnosis was juvenile granulosa cell tumor.
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PMID:Androgenic juvenile granulosa cell tumor of the ovary with cystic presentation: a case report. 1762 97

Becoming a phenotypic male is ultimately determined by androgen-induced masculinization. Disorders of fetal masculinization, resulting in hypospadias or cryptorchidism, are common, but their cause remains unclear. Together with the adult-onset disorders low sperm count and testicular cancer, they can constitute a testicular dysgenesis syndrome (TDS). Although masculinization is well studied, no unifying concept explains normal male reproductive development and its abnormalities, including TDS. We exposed rat fetuses to either anti-androgens or androgens and showed that masculinization of all reproductive tract tissues was programmed by androgen action during a common fetal programming window. This preceded morphological differentiation, when androgen action was, surprisingly, unnecessary. Only within the programming window did blocking androgen action induce hypospadias and cryptorchidism and altered penile length in male rats, all of which correlated with anogenital distance (AGD). Androgen-driven masculinization of females was also confined to the same programming window. This work has identified in rats a common programming window in which androgen action is essential for normal reproductive tract masculinization and has highlighted that measuring AGD in neonatal humans could provide a noninvasive method to predict neonatal and adult reproductive disorders. Based on the timings in rats, we believe the programming window in humans is likely to be 8-14 weeks of gestation.
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PMID:Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism. 1834 Mar 80


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