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Query: UMLS:C0042755 (
masculinization
)
2,562
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In order to determine whether the gonadal and hypophyseal modes of regulation recently reported for the microsomal enzymes of hepatic steroid metabolism are also valid for cytoplasmic enzymes, three enzymes whose activities exhibit sex differences (male:female activity ratio shown in brackets), 5beta-reductase(1.7:1), 20alpha-hydroxysteroid dehydrogenase(5 : 1) and
17beta-hydroxysteroid dehydrogenase
(4:1), as well as one enzyme whose activity shows no sex difference, 3beta-hydroxy-delta5-steroid dehydrogenase, were investigated after various interferences with the endocrine balance (gonadectomy, hypophysectomy, combination of both operations, administration of testosterone or oestradiol). From the results of this and a previous study the following statements can be made about the endocrine control of hepatic enzyme activities. Those enzymes whose activities show sex differences are either androgen or oestrogen dependent; the sex hormone acts in either an inductive or repressive manner. 1) Criteria for androgen dependency are the feminization of enzyme activity after testectomy or inhibition of testicular function by administration of oestradiol;
masculinization
of the enzyme activity after administration of testosterone to male or female castrates. Using these criteria the following enzymes investigated in this laboratory fall into this category: all microsomal enzymes which show sex differences in their activity (3alpha-, 3beta-, delta4-3beta, 20-hydroxysteroid dehydrogenase; cortisone alpha-reductase; steroid hydroxylases and 16alpha-hydroxylase) as well as the cytoplasmic 20alpha-hydroxysteroid dehydrogenase. Apart from the single exception of 20alpha-hydroxy-steroid dehydrogenase the presence of the hypophysis is obligatory for the androgen to be effective. The hypophysis does not only work in a permissive manner, but participates in establishing the sex specific activity levels in a manner which is antagonistic to the androgen action. 2) Criteria for oestrogen dependency are that the female animal reacts to gonadectomy, as well as to the inhibition of ovarian function after testosterone administration, by a
masculinization
of the enzyme activities. After administration of oestradiol, but not gonadectomy, the male animal exhibits typical female activity. Using these criteria the cytoplasmic 5beta-reductase and
17beta-hydroxysteroid dehydrogenase
are oestrogen dependent. The repressive oestrogen effect observed on
17beta-hydroxysteroid dehydrogenase
is antagonistic to hypophyseal action, whereas in the case of 5beta-reductase it is synergistic. 3) The activities of cytoplasmic 3beta-hydroxy-delta5-steroid dehydrogenase and microsomal 7alpha-hydroxylase show no sex differences and are not influenced by any interference with the endocrine balance.
...
PMID:The hypophysis in the regulation of androgen and oestrogen dependent enzyme activities of steroid hormone metabolism in rat liver cytosol. 117 83
With the exception of 3beta-hydroxy-steroid dehydrogenase all the hydroxysteroid dehydrogenases of adult male and female rat kidney show significant sex differences in their activities. Interference with the organisms endocrine balance (gonadectomy on day 25 of life, hypophysectomy on day 50, a combination of both these operations, administration of testosterone or oestradiol) demonstrates that the sexually differentiated enzyme activities may be classified as androgen or oestrogen dependent, the respective sex hormone acting either in an inductive or repressive manner. The criteria for androgen dependency (microsomal 3alpha- and 20beta-, cytoplasmic 17beta- and 20alpha- hydroxysteroid dehydrogenase) are the feminization of the enzyme activity in male animals after castration and the
masculinization
of the activity in male and female castrates as well as in normal female animals after administration of testosterone. This latter effect on normal females cannot be a testosterone mediated inhibition of ovarian function since ovariectomy has no effect. For 3alpha-, 20alpha-, and 20beta-hydroxysteroid dehydrogenase the effects of hypophysectomy parallel those of gonadectomy. However, after hypophysectomy the activity of
17beta-hydroxysteroid dehydrogenase
falls significantly below the gonadectomized level. The androgen effect on 3alpha and 20beta-hydroxysteroid dehydrogenase is independent of the hypophysis, whereas that of 17beta- and 20alpha-hydroxysteroid dehydrogenase is mediated by the hypophysis.
...
PMID:The role of the gonads and the hypophysis in the regulation of hydroxysteroid dehydrogenase activities in rat kidney. 117 84
Individuals with 5alpha-reductase-2 deficiency (5alpha-RD-2) and
17beta-hydroxysteroid dehydrogenase
-3 deficiency (17beta-HSD-3) are often raised as girls. Over the past number of years, this policy has been challenged because many individuals with these conditions develop a male gender identity and make a gender role change after puberty. The findings also raised doubts regarding the hypothesis that children are psychosexually neutral at birth and emphasized the potential role of prenatal brain exposure to androgens in gender development. If prenatal exposure to androgens is a major contributor to gender identity development, one would expect that all, or nearly all, affected individuals, even when raised as girls, would develop a male gender identity and make a gender role switch later in life. However, an estimation of the prevalence of gender role changes, based on the current literature, shows that gender role changes occur frequently, but not invariably. Gender role changes were reported in 56-63% of cases with 5alpha-RD-2 and 39-64% of cases with 17beta-HSD-3 who were raised as girls. The changes were usually made in adolescence and early adulthood. In these two syndromes, the degree of external genital
masculinization
at birth does not seem to be related to gender role changes in a systematic way.
...
PMID:Gender change in 46,XY persons with 5alpha-reductase-2 deficiency and 17beta-hydroxysteroid dehydrogenase-3 deficiency. 1601 Apr 63
The fungicide prochloraz has got multiple mechanisms of action that may influence the demasculinizing and reproductive toxic effects of the compound. In the present study, Wistar rats were dosed perinatally with prochloraz (50 and 150 mg/kg/day) from gestational day (GD) 7 to postnatal day (PND) 16. Caesarian sections were performed on selected dams at GD 21, while others were allowed to give birth to pups that were followed until PND 16. Prochloraz caused mild dysgenesis of the male external genitalia as well as reduced anogenital distance and retention of nipples in male pups. An increased anogenital distance indicated
virilization
of female pups. Effects on steroidogenesis in male fetuses became evident as decreased testicular and plasma levels of testosterone and increased levels of progesterone. Ex vivo synthesis of both steroid hormones was qualitatively similarly affected by prochloraz. Immunohistochemistry of fetal testes showed increased expression of 17alpha-hydroxylase/17,20-lyase (P450c17) and a reduction in
17beta-hydroxysteroid dehydrogenase
(type 10) expression, whereas no changes in expression of genes involved in testicular steroidogenesis were observed. Increased expression of P450c17 mRNA was observed in fetal male adrenals, and the androgen-regulated genes ornithine decarboxylase, prostatic binding protein C3 as well as insulin-like growth factor I mRNA were reduced in ventral prostates PND 16. These results indicate that reduced activity of P450c17 may be a primary cause of the disrupted fetal steroidogenesis and that an altered androgen metabolism may play a role as well. In vitro studies on human adrenocortical carcinoma cells supported the findings in vivo as reduced testosterone and increased progesterone levels were observed. Overall, these results together indicate that prochloraz acts directly on the fetal testis to inhibit steroidogenesis and that this effect is exhibited at protein, and not at genomic, level.
...
PMID:Mechanisms of action underlying the antiandrogenic effects of the fungicide prochloraz. 1637 36
Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), are typical environmental contaminants and suspected endocrine-disrupting chemicals because they cause
masculinization
in female mollusks. However, it remains unclear whether organotin compounds also cause crucial toxicities in human sexual development and reproductive functions. We investigated the effects of 17 tin compounds on the catalytic activity and mRNA expression of
17beta-hydroxysteroid dehydrogenase
type I (17beta-HSD I) in human choriocarcinoma JAr cells. At nontoxic concentrations, both trialkyltins with propyl, butyl or cyclohexyl substituents on the tin atom and triphenyltin (TPT) enhanced 17beta-HSD I mRNA transcription and enzyme activity in a dose-dependent fashion. Although tetraalkyltin compounds such as tetrabutyltin and tributylvinyltin also increased the mRNA expression and enzyme activity of 17beta-HSD I, the concentrations necessary for activation were >30-100 times greater than those for trialkyltins. Inorganic tin had no effect on the catalytic activity and mRNA expression of 17beta-HSD I. Interestingly, diphenyltin and monophenyltin, which are metabolites of TPT, enhanced 17beta-HSD I activity with a concomitant increase in mRNA expression, whereas dibutyltin and monobutyltin, which are metabolites of tributyltin, enhanced 17beta-HSD I activity without a concomitant increase in mRNA expression. These results suggest that organotin compounds are potent stimulators of 17beta-estradiol biosynthesis to enhance 17beta-HSD I activity in the human placenta in vitro; the placenta represents a potential target organ for these compounds, whose endocrine-disrupting effects might be the result of local changes in 17beta-estradiol concentrations in pregnant women.
...
PMID:Organotin compounds enhance 17beta-hydroxysteroid dehydrogenase type I activity in human choriocarcinoma JAr cells: potential promotion of 17beta-estradiol biosynthesis in human placenta. 1651 93
Mature cystic teratoma (MCT) is rarely involved in the overproduction of steroid hormones in contrast to sex cord stromal tumors. A 31-year-old woman visited our hospital with hirsutism, hoarseness, and hair loss from the scalp. Serum testosterone and free-testosterone levels were 7.3 ng/ml and 2.3 pg/ml, respectively, which were markedly in excess of the age adjusted female standard levels. Basal blood levels of steroid hormones and serum levels of 17-hydroxyprogesterone at 1 h after intravenous injection of adrenocorticotropic hormone demonstrated that 21-hydroxylase deficiency was not the underlying cause of her
virilization
. A subsequent chromosomal test with G-banding revealed a karyotype of 46XX. Magnetic resonance imaging revealed a mass in the left ovary, which was subsequently diagnosed as MCT. Detailed pathological analysis of the tumor indicated that it was comprised of skin components, sweat glands, with hair and fat texture, glandular epithelium and fibrous connective tissue, consistent with the characteristic composition of MCT. Immunohistochemical analysis demonstrated marked immunoreactivity of
17beta-hydroxysteroid dehydrogenase
(HSD17B5), an enzyme that can convert androstenedione to testosterone. Following surgical removal of the tumor, testosterone and free testosterone levels were markedly decreased (0.3 ng/ml and 0.4 pg/ml, respectively) and other symptoms abated. In conclusion, this is the first report of an ovarian MCT associated with clinical
virilization
caused by the ectopic production of testosterone possibly because of an overexpression of intratumoral HSD17B5.
...
PMID:Virilism and Ectopic Expression of HSD17B5 in Mature Cystic Teratoma. 2819 Aug 56