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I Mowszowicz

Publications and source records attributed to I Mowszowicz.

At least 55 records · Page 3Linked to original sources
PubMed1986

Changes in the metabolic pattern of estrogens as a function of age in cultured myometrial cells: synthesis of a lipoidal derivative of estradiol.

The effect of ageing on estradiol (E2) metabolism has been studied systematically in cultured ovine myometrial cells from the 2nd to the 25th subculture. Cell monolayers were incubated for various amounts of time with [3H]E2, and metabolites isolated from cells or medium by thin-layer chromatography (TLC). The main metabolites identified were estrone (E1), estriol (E3), 16-epi-E3 and a lipoidal derivative of E2 (LE2). The latter had an Rf of 0.90 and was recognized by its comigration with fatty acid on TLC and the release of E2 after alkaline hydrolysis. In contrast to the other metabolites, LE2 was found only in cells and was never secreted in the medium. In "young" cells (2nd subculture) the main metabolite was E1 which represented 16.3% of the total radioactivity after 2 h of incubation and 33% after 8 h both in cells and medium. LE2 appeared very slowly and represented only 13% after 8 h of incubation. In contrast in "old" cells (i.e. 10th subculture) LE2 had become the most abundant metabolite representing as much as 25% of the total cellular radioactivity. This change from one metabolic pattern to the other was progressive and associated with a decrease in 17 beta-hydroxysteroid dehydrogenase (SDH) activity. LE2 became prevalent relative to E1 around the 5th subculture. In conclusion, ageing in cultured myometrial cells is accompanied by a qualitative change in E2 metabolism, switching from E1 formation (an inactivation mechanism) to LE2 biosynthesis (a storage mechanism).

Animals↗
PubMed1986

Androgen insensitivity in oligospermic men: a reappraisal.

Androgen insensitivity has been reported to be present in as many as 40% of patients with severe oligospermia. In order to evaluate further the role of androgen resistance in male infertility we studied 24 men with severe oligospermia. Plasma T and LH were measured by RIA and the T X LH product was calculated. Fibroblasts were grown from genital skin obtained during testicular biopsies and androgen receptor maximal binding capacity (BMAX) and affinity (KD) were measured in fibroblast monolayers. Pubic skin 5 alpha-reductase activity, an androgen-dependent enzyme, was measured in skin homogenates. Plasma T values were in the upper normal range [7.0 +/- 1.7 (SEM) ng ml-1] whereas the T X LH product was high (greater than 50) in only six patients. Mean BMAX and KD values for the androgen receptor were normal [BMAX: 788 +/- 259 fmol mg DNA-1 (patients, n = 20), 726 +/- 227 (normal men, n = 20), and KD: 0.27 +/- 0.24 (patients, n = 20), 0.18 +/- 0.09 (normal men, n = 15), respectively]. However, four men had supranormal KD values. The mean BMAX was also normal when the group of men with sperm densities below 10(6) per ejaculate was considered separately. Public skin 5 alpha-reductase activity was normal in all but four patients (patients: 177.1 +/- 91 fmol/mg skin/h, n = 30, normal men: 210 +/- 45, n = 20 patients). In conclusion, androgen receptor BMAX levels were normal in all patients studied, regardless of the sperm density and the T X LH product. Pubic skin 5 alpha-reductase activity was also normal in all but four patients. In these four patients, a qualitative defect of the androgen receptor cannot be excluded. In this group of patients with severe oligospermia, infertility did not seem to be related to quantitative abnormality of the androgen receptor as was previously reported.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1985

Late-onset adrenal hyperplasia in hirsutism.

We studied the incidence of late-onset adrenal hyperplasia as a cause of hirsutism, its association with the major histocompatibility complex, and its clinical expression. Twenty-four of 400 women seen because of hirsutism were found to have late-onset adrenal hyperplasia, diagnosed on the basis of a high plasma level of 17-hydroxyprogesterone, and its marked increase after ACTH stimulation. The degree of hirsutism varied widely. Plasma antigen levels were high, especially the level of androstenedione, whereas 5 alpha-reductase activity, considered to be a good index of peripheral androgen utilization, showed frequent normal or low values. The 24 patients were genotyped, along with 84 family members, and plasma hormones were measured in the family members. We found a high correlation between late-onset adrenal hyperplasia and HLA antigens B14 and Aw33. Similar biologic profiles were observed in the patients and those of their siblings who were HLA identical (n = 9), confirming that late-onset adrenal hyperplasia is linked to the histocompatibility complex. These nine siblings had no hirsutism. We therefore conclude that the role of skin sensitivity to androgens is important in determining the clinical expression of this disorder.

17-alpha-Hydroxyprogesterone↗
PubMed1984

Androgen metabolism in hirsute patients treated with cyproterone acetate.

Cyproterone acetate (CPA) in association with percutaneously administered estradiol has been used for the treatment of 150 hirsute patients for periods ranging from 6 months to 3 years. A spectacular clinical improvement ensued. Plasma testosterone (T) and androstenedione (A) fell from 69.0 +/- 24 to 33.0 +/- 8 and 210 +/- 103 to 119 +/- 25 ng/dl (mean +/- SD) respectively after 3 months of treatment and remained low thereafter. In contrast, T glucuronide (TG) and 3 alpha-androstanediol (Adiol) remained high during the whole course of treatment: 37 +/- 9 and 115 +/- 43 micrograms/24 h respectively. In vitro T 5 alpha-reductase activity (5 alpha-R) in pubic skin decreased from 147 +/- 34 to 79 +/- 17 fmol/mg skin after 1 year of treatment. To elucidate the discrepancy between plasma and urinary androgens levels, T production rate (PR) and metabolic clearance rate (MCR) were measured with the constant infusion technique in 7 patients before and after 6 months of treatment. PR decreased from 988 +/- 205 to 380 +/- 140 micrograms/24 h (mean +/- SD). In contrast MCRT increased from 1275 +/- 200 to 1632 +/- 360 1/24 h; this increase in MCRT explains the striking plasma T concentration fall and the high TG and Adiol excretion relative to the decrease in PR. Antipyrine clearance rate (n = 8) increased from 36.3 +/- 5.2 to 51.5 +/- 7.4 ml/min whereas 6 beta hydroxycortisol remained unchanged. In conclusion, CPA acts through several mechanisms: (1) it lowers the androgen input to the target cells by (a) depressing T production through its antigonadotropic effect and (b) accelerating T metabolic inactivation due to a partial enzymatic inducer effect on the liver; (2) at the target cell level it competes with any remaining T for the receptor binding sites; (3) the decrease in the androgen-dependent skin 5 alpha-R is a consequence of both actions of androgen suppression and androgen receptor blockade; it reinforces the antiandrogenic effect of CPA.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1983

Further characterization of 17 beta-hydroxysteroid dehydrogenase activity in cultured myometrial cells: cofactor dependency and subcellular localization.

To further characterize 17 beta-hydroxysteroid dehydrogenase (17 beta-SDH) from cultured ovine myometrial cells, an assay was established in whole cell homogenates and cell subfractions. Tritiated estradiol (E2) was incubated in the presence of an excess of cofactor and estrone (E1) formed purified by thin-layer chromatography. The enzyme activity was linear with time up to 2 hours and with protein concentration up to 0.7 mg/ml at the substrate concentration used (5 X 10(-9) M). The routine assay was for 30 min in the presence of 0.5 mg/ml of protein. Both NAD+ or NADP+ could sustain enzyme activity but NAD+ was twice as much efficient. Most of the enzyme activity was associated with the microsome and mitochondrial membranes. The addition of an excess (1000 microM) of NAD+ to the incubation medium prevented the progressive decline observed with time in a given subculture in the intact cell monolayer assay, supporting our previous hypothesis that this decline was due to cofactor depletion. In contrast, the slow and irreversible decline of enzyme activity observed in successive subcultures was not prevented by the addition of cofactor to the homogenate and thus reflects another phenomenon, probably a change in metabolism with age.

17-Hydroxysteroid Dehydrogenases↗
PubMed1983

Dihydrotestosterone stimulates 5 alpha-reductase activity in pubic skin fibroblasts.

In vivo, the 5 alpha-reduction of testosterone (T) to dihydrotestosterone (DHT) is androgen dependent in pubic skin but not in the skin of the external genitalia. The aim of the present study was to determine whether pubic skin fibroblasts (PSF) had retained this androgen dependency. PSF were prepared from explants of skin from normal subjects (four men, three women) and three patients with complete form of the testicular feminization syndrome. Culture medium containing 5% fetal calf serum and DHT was added 24 h after subculture (day 1) and renewed every other day. 5 alpha-Reductase was assayed on day 4 or day 8 by incubation of intact cell monolayers with [3H]T (2 nM), extraction of the medium, and chromatography of the metabolites; DNA was assayed in the cell pellets; 5 alpha-reductase was expressed as fmol/micrograms DNA . h. Controls were untreated plates from the same subcultures. DHT had no effect on cell DNA, whereas it resulted in a dose-dependent increase in 5 alpha-reductase activity. In seven PSF strains tested, DHT (10(-7) M) increased 5 alpha-reductase activity 2- to 4-fold over the control levels. This effect was abolished by the simultaneous addition of cyproterone acetate (2 X 10(-6) M) and was not observed in PSF from testicular feminization syndrome patients, suggesting that it was indeed mediated via the androgen receptor. T but not estradiol or cortisol also increased 5 alpha-reductase activity in PSF. The effect of androgens was suppressed by protein synthesis inhibitors. These data provide strong evidence that PSF respond to androgens via a receptor mediated mechanism, and that 5 alpha-reductase can be used as a marker of androgen action in pubic skin in vitro as well as in vivo.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1983

Androgen binding capacity and 5 alpha-reductase activity in pubic skin fibroblasts from hirsute patients.

We have measured the total (cytosolic plus nuclear) androgen binding capacity of pubic skin fibroblasts from nine patients with hirsutism of various origin. Confluent intact cell monolayers were incubated with increasing concentrations (0.05-2 nM) of [3H]dihydrotestosterone ([3H]DHT) with or without a 200-fold excess of unlabeled DHT. The androgen binding capacities (mean +/- SD) were similar in normal men (411 +/- 171 fmol/mg DNA), women (310 +/- 103 fmol/mg DNA), and hirsute patients (313 +/- 141 fmol/mg DNA) regardless of the plasma androgen levels. In contrast, the 5 alpha-reductase level in pubic skin fibroblasts (mean +/- SD) was, as previously described, higher in hirsute women (3.3 +/- 2.6 fmol/micrograms DNA . h) than in normal women (1.1 +/- 0.6 fmol/microgram DNA . h; P less than 0.05). We conclude from these data that: 1) increased androgen binding capacity cannot be held responsible for hypersensitivity to androgens in hirsutism; 2) the androgen receptor is not regulated by androgens in human skin, as similar levels are observed in men, women, and hirsute patients; 3) this contrasts with 5 alpha-reductase activity and emphasizes the importance of this enzyme as an amplifier of androgen action in areas where it is stimulated by androgens, such as pubic skin.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1983

[The mechanism of action of cyproterone acetate in the treatment of hirsutism].

Cyproterone acetate (CPA) in association with percutaneously offinistered estradiol has been used for the treatment of 150 hirsute patients for periods ranging from 6 months to 3 years. A spectacular clinical improvement ensued. Plasma testosterone (T) and androstenedione (A) fell from 69 +/- 24 to 33 +/- 8 and 210 +/- 103 to 119 +/- 25 ng/dl (mean +/- SD) respectively after 3 months of treatment and remained low thereafter. In contrast, T glucuronide (Tg) and 3 alpha-androstanediol (Adiol) remained high during the whole course of treatment: 37 +/- 9 and 115 +/- 43 micrograms/24 h respectively. In vitro T 5 alpha-reductase activity (5 alpha-R) in pubic skin decreased from 147 +/- 34 to 79 +/- 17 fmol/mg skin after 1 year of treatment. To elucidate the discrepancy between plasma and urinary androgens levels, T production rate (PR) and metabolic clearance rate (MCR) were measured with the constant infusion technique in 6 patients before and after 6 months of treatment. PR decreased from 988 +/- 205 to 380 +/- 140 micrograms/24 h (mean +/- SD). In contrast MCRT increased from 1275 +/- 200 to 1632 +/- 360 1/24 h; this increase in MCRT explains the striking plasma T concentration fall and the high TG and Adiol excretion relative to the decrease in PR. Antipyrine clearance rate (n = 8) increased from 36.3 +/- 5.2 to 51.5 +/- 7.4 ml/min whereas urinary/6 beta hydroxycortisol remained unchanged. In conclusion, CPA acts through several mechanisms:(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1982

17 beta-hydroxysteroid dehydrogenase activity in cultured myometrial cells: effect of serial subcultures.

17 beta-Hydroxysteroid dehydrogenase (17 beta-SDH) activity was studied in culture ovine myometrial cells. After primary culture, cells were routinely subcultured (every 7th day), seeded at 5 x 10(5) cells per dish and grown in a medium with 2% of serum. 17 beta-SDH activity was measured by incubating intact cell monolayers with [3H]-estradiol (5 x 10(-9) M) in serum-free medium. Metabolites were extracted from both cells and medium, and separated by thin-layer chromatography. 17 beta-SDH was expressed as total E1 formed (cells + medium) in fmol/mg of protein as a function of time. 17 beta-SDH has an approximate Km of 5 x 10(-6) M. After 3 min of incubation, all measurable E1 is within the cells; it is progressively released but after 1 h only 40% of E1 is found in the medium. 17 beta-SDH decreases from day 2 to day 8 of each subculture, whereas total proteins increase. Subculture partially restores 17 beta-SDH activity so that it is always higher on day 2 of any subculture than on day 8 of the previous one, however a progressive decline occurs with successive subcultures. This decline parallels the slowing of cell growth and overall protein synthesis and probably reflects cell ageing.

17-Hydroxysteroid Dehydrogenases↗
PubMed1982

Exaggerated prolactin response of thyrotropin-releasing hormone in women with anovulatory cycles: possible role of endogenous estrogens and effect of bromocriptine.

Twenty-one women 18 to 36 years old, presenting with chronic anovulation, were compared with 10 normally cycling women. The patients were characterized by low progesterone (P) levels (0.93 +/- 0.14 ng/ml versus 15.5 +/- 1.4 in controls), whereas 17 beta-estradiol (E2) was moderately decreased (110.2 +/- 8.3 pg/ml versus 162.8 +/- 14.5 in controls) realizing a relative hyperestrogenism. Basal prolactin (PRL) levels were not elevated (12.1 +/- 0.97 ng/ml versus 9.2 +/- 0.7 in controls), but after thyrotropin-releasing hormone (TRH) stimulation an exaggerated response was observed (114.5 +/- 7 ng/ml versus 55.8 +/- 9 in controls). Patients were treated with bromocriptine (1.25 mg 2 times a day) for 3 months. Fifteen responded with ovulatory cycles, and five became pregnant. Progesterone increased significantly (10.2 +/- 1.3 ng/ml), whereas in patients who did not ovulate P increased only slightly (1.56 +/- 0.18 ng/ml). The particular endocrine profile of these patients (P/E2 imbalance) realizing relative hyperestrogenism may be responsible for the exaggerated PRL response to TRH. Bromocriptine, in reducing this transient, or masked, hyperprolactinemia, allows in many patients the return to ovulatory cycles. This mechanism may be one of the possible pathways leading to chronic functional or organic hyperprolactinemia.

Adolescent↗
PubMed1981

Androgen receptor in human skin cytosol.

Human skin, an accessible tissue, is an androgen target organ. We have measured the androgen-binding capacity of human skin cytosol using either 5 alpha[3H]dihydrotestosterone ([3H]DHT) or [3H]methyltrienolone ([3H]R-1881) as ligand. Samples were incubated for 20 h at 0 C, and dextran-coated charcoal was used to separate bound from free steroids. The androgen receptor has a high affinity for both ligands (0.23 +/- 0.04 nM for [3H]DHT; 0.32 +/- 0.16 nM for [3H]R-1881). Testosterone, cyproterone acetate, and, to a lesser extent, estradiol also bind this protein. Progesterone displaces R-1881 from its binding sites, whereas its 5 alpha-reduced metabolite somewhat inhibits DHT binding. The highest binding capacity is measured in cytosol of skin from external genitalia (129.14 +/- 58.0 fmol/g skin; n = 34); it is lower in pubic skin (21.8 +/- 13 fmol/g skin; n = 6). There is no variation as a function of age or sex in genital skin; the higher concentrations observed in the cytosol of pubic skin of women compared to that of men are probably related to lower levels of endogenous steroids. Whereas most patients with the complete form of the testicular feminization syndrome do not have detectable concentrations of androgen receptor, one patient with apparent complete clinical androgen insensitivity had a normal androgen-binding capacity. The parity of values in genital skin from men and women, the absence of variation with age, and the presence of a cytosolic androgen receptor in some androgen-insensitive patients suggest that the androgen receptor in human skin cytosol is not regulated by androgens.

Adolescent↗
PubMed1981

Hirsutism.

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17-Ketosteroids↗
PubMed1980

Testosterone 5 alpha-reductase activity of skin fibroblasts. Increase with serial subcultures.

Cultures of skin fibroblasts from different anatomical sites have been established and testosterone 5 alpha-reductase assayed after the 2nd, 6th and 12th subcultures. After the 2nd passage, 5 alpha-reduction of testosterone to both dihydrotestosterone and androstanediols correlated well with that measured in direct assays performed in total skin homogenates; this is an additional evidence that different types of skin have specific levels of testosterone 5 alpha-reductase activity. However, there was a marked increase in 5 alpha-reductase activity with successive subcultures (X4--5 between 2nd and 12th subcultures) in all the cell strains studied. This finding could explain why data concerning 5 alpha-reductase in cultured skin fibroblasts are often conflicting with those in skin homogenates. It emphasizes the necessity of performing enzyme assays after the same number of passages to allow comparison from strain to strain. Different hypotheses are discussed in order to explain such variations of 5 alpha-reductase in cultured human skin fibroblasts.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗