Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.3 (HSD)
 3,464 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A partial testicular defect in testosterone secretion has been documented in a pubertal male with a congenital adrenal hyperplasia due to hereditary deficiency of the delta5-isomerase-3beta-hydroxysteroid dehydrogenase enzyme complex (delta5-3beta-HSD). Diagnosis of the enzymatic defect is based on the clinical picture of ambiguous genitalia and salt-losing crisis in infancy, together with high urinary delta5-pregnenetriol and plasma dehydroepiandrosterone when the patient was taken off replacement corticoid treatment. No hormonal response to ACTH or salt deprivation was demonstrable. In addition, in vivo studies revealed a partial enzymatic defect in the testis. Although plasma testosterone was low-normal (250 ng/100 ml), plasma delta5-androstenediol was markedly elevated and rose to a greater extent than testosterone after human chorionic gonadotropin administration. In vitro testicular incubation studies suggested a testicular delta5-3beta-HSD enzyme defect with less delta4 products formed from delta5 precursors than in a control testis. Histochemical studies of the testis were also consistent with this defect. Testicular biopsy revealed spermatogenic arrest, generally diminished Leydig cells, but with focal areas of Leydig cell hyperplasia as well as benign Leydig cell hyperplasia as well as benign Leudig cell nodules within the spermatic cord. In vivo studies of steroid metabolism suggested intact peripheral or hepatic delta5-3beta-HSD activity. These studies imply that delta5-3beta-HSD activity differs in the gonad, adrenal, and peripheral organs. These findings are compatible with the concept that the enzyme complex consists of subunits and/or that enzymes in these organs are under different genetic control.
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PMID:Persistent testicular delta5-isomerase-3beta-hydroxysteroid dehydrogenase (delta5-3beta-HSD) deficiency in the delta5-3beta-HSD form of congenital adrenal hyperplasia. 16 81

Aged (12- to 14-month-old) estrous and diestrous C57BL mice exhibited lower histochemically demonstrable ovarian delta5-3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity in thecal, luteal, and interstitial cells, and lower (P less than 0.01) ovarian 3beta-HSD concentration and total content than did young (3-month-old) estrous animals. Administration of pregnant mare serum (PMS, 10 IU subcutaneously), followed in 40 hours by human chorionic gonadotropin (HCG, 5 IU subcutaneously) or HCG (2 IU daily for 4 days) alone, restored luteal and interstitial 3beta-HSD in aged mice. Follicular, lutea, and interstitial 3beta-HSD activity was increased in aged mice by a single PMS injection (10 IU). The total ovarian dehydrogenase concentration was increased 100% in aged animals by PMS and/or HCG administration. Restoration of histochemically demonstrable ovarian 3beta-HSD and total enzyme content in aged mice by PMS and/or HCG indicates ovarian sensitivity to gonadotropin and subnormal tropic hormone stimulation of the ovary in situ.
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PMID:Pregnant mare serum and human chorionic gonadotropin stimulate ovarian delta5-3beta-hydroxysteroid dehydrogenase in aged mice. 55 85

The study made by histochemistry shows that the delta5-3 beta-hydroxysteroid-dehydrogenase (delta5-3 beta-HSDH) activity which is positive in the fresh placental tissue disappears after 24 h of culture but is maintained much longer if culture medium is supplemented with human chorionic gonadotropin (15 UI of HCG). The biochemical study confirms the delta5-3 beta-HSDH activity decrease during the first 24 h of culture. The enzymatic activity is restored during the following six days and this phenomenon is stimulated by the addition of HCG in the culture medium.
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PMID:[Delta 5-3 beta hydroxysteroid dehydrogenase activity in the human full term placenta after culture: the effect of chorionic gonatropin]. 80 53

We have previously demonstrated that cyclosporine inhibits testosterone (T) biosynthesis in vivo. To better understand the mechanism by which CsA inhibits T synthesis, interstitial cells were isolated from rat testes and incubated in the standard medium 199 with or without CsA (0-10 micrograms/ml) in the presence or absence of human chorionic gonadotropin (hCG, 10(-7) M) and 8-bromo cyclic AMP (cAMP, 0.5 mM) for 3 hr at 32 degrees C. The levels of cAMP and T were determined by RIA. CsA did not inhibit the basal secretion of T, but inhibited hCG-stimulated T production in a dose-dependent manner (4 ng/10(6) cells vs. 10 ng/10(6) cells at a CsA dose of 5 micrograms/ml, P less than 0.05). Radioligand binding of 125I-hLH to testicular membranes was not affected by CsA, as CsA did not compete with hCG/LH for binding sites (25-28% binding with or without CsA). Similarly, the MIX-stimulated cAMP production was not affected by CsA (24.03 +/- 1.09 vs. 20.60 +/- 0.38 pmol/10(6) cells), suggesting that CsA does not inhibit the accumulation of the second messenger. However, when interstitial cells were incubated with CsA in the presence of cAMP, a significant dose-dependent decline in T secretion was observed (7 ng/10(6) cells vs. 20 ng/10(6) cells at a CsA dose of 5 micrograms/ml). To determine whether CsA inhibits the steps beyond cAMP stimulation of T secretion, the kinetic parameters (Km and Vmax) of steroidogenic enzymes, delta 4-3 keto-17 alpha hydroxylase (17 alpha-hydroxylase), and delta 4-3 keto-17 beta hydroxy steroid dehydrogenase (17B-HSD) were determined by using Michaelis Menten analysis. Results are shown in the presence of CsA vs. no CsA: Km and Vmax values for 17 alpha-hydroxylase were (2.32 vs. 7.98 microM) and (27.96 vs. 100.97 pmol/mg protein/min), respectively. For 17B-HSD the Km and Vmax were (2.14 vs. 1.52 microM) and (15 vs. 15 pmol/mg protein/min), respectively. These results indicate that CsA inhibits the activity of 17 alpha-hydroxylase uncompetitively and 17B-HSD activity competitively. In conclusion the primary site for CsA inhibition is the cAMP stimulation and, CsA inhibits T synthesis at multiple sites.
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PMID:The mechanism of cyclosporine's action in the inhibition of testosterone biosynthesis by rat Leydig cells in vitro. 131 Jan 71

Birth control vaccines inducing antibodies against human chorionic gonadotropin (hCG) are in the forefront of development among all potential birth control vaccines. 2 such vaccines have been developed; one of them uses the 37-amino acid carboxy terminal peptide of beta-hCG (the CTP vaccine), and the other employs the entire beta-hCG (the beta-hCG vaccine) or its heterospecies dimer with an alpha subunit for ovine luteinizing hormone (the HSD vaccine). A Phase I clinical trial with the CTP vaccine was conducted in Australia in 39 women, 10 serving as controls and 20 immunized with the vaccine. No important adverse reactions were observed and the immune response was reversible. Menstrual pattern was unchanged. More extensive Phase I clinical trials were conducted with the beta-hCG/HSD vaccines in 5 centers in India and in Finland, Chile and Brazil which invariably confirmed the lack of side effects and the reversibility of the vaccine. The HSD vaccine proceeded to Phase II trials conducted in 3 major centers in India. 14 women were exposed to the risk of pregnancy for 12 months and 2 completed 19 months without becoming pregnant. As of February 1, 1992, 642 cycles of exposure had been recorded. Only 1 pregnancy had taken place above the threshold level of 59 ng/ml bioneutralization capacity. Research results also indicate that a recombinant vaccine in a live vector such as vaccinia would require less frequent injections, and elicit a high antibody response capable of preventing pregnancy. Vaccines have entered Phase 1 clinical trials employing vaccinia as a vector as potential vaccines against the human immunodeficiency virus (HIV). Vaccination-inducing antibodies against hCG may have an application in the treatment of lung cancer, as a cell line, ChaGo, developed from a human lung cancer patient, makes hCG and its subunits.
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PMID:Anti-hCG vaccines are in clinical trials. 151 26

In the family Bufonidae, male toads possess rudimentary ovaries, called Bidder's organs, which are attached to the testes. The mechanisms involved in the inhibition of oogenesis in these structures were investigated in male Bufo woodhousii. Orchidectomized and sham-operated animals were injected with gonadotropins (pregnant mare serum gonadotropin [PMSG] + human chorionic gonadotropin [hCG]) for 26 days and the effects of these hormones on oogenesis and steroidogenic activity (3 beta-hydroxysteroid dehydrogenase [3 beta-HSD] and 17 beta-HSD) in the Bidder's organ were quantified. Bilateral orchidectomy alone resulted in the growth of bidderian oocytes and a shift towards later stages of oogenesis. Gonadotropins enhanced this effect and stimulated the proliferation of new germ cells. In the presence of testes, however, bidderian oogenesis remained inhibited despite high levels of circulating gonadotropins. In both ooplasm and follicular layers of the bidderian oocytes of all toads, 3 beta-HSD and 17 beta-HSD activities were detected by histochemistry. Follicular enzymatic activity increased in orchidectomized toads treated with PMSG + hCG but decreased in sham-operated toads treated with gonadotropins. Testis weights, rudimentary oviduct weights, and plasma steroid levels increased in intact toads injected with hCG + PMSG. Gonadotropins had no effect on plasma steroid levels in orchidectomized toads, however. These results suggest that the testes play a major role in the inhibition of oogenesis in Bidder's organs of B. woodhousii and are a major source of androgens. High circulating levels of gonadotropins do not overcome the inhibitory effects of the testes.
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PMID:The effects of orchidectomy and gonadotropins on steroidogenesis and oogenesis in Bidder's organs of the toad Bufo woodhousii. 174 14

Ketoconazole (KCZ), a widely used antifungal drug, has been reported in humans to inhibit adrenal and testicular steroidogenesis by interfering with the cytochrome P-450-dependent enzymes. The purpose of this study was to investigate the drug effect on steroidogenic human granulosa-luteal cells, obtained by follicular aspiration from mature follicles of gonadotropin-treated women. Cells were cultured in long-term monolayers, and the steroid production was assayed by radioimmunoassay. A profound inhibition of ovarian cell secretion of progesterone (P), testosterone (T) and estradiol was found. At a low concentration (5 micrograms/ml), KCZ failed to inhibit the conversion of pregnenolone to P, mediated by the non-cytochrome 3 beta-hydroxysteroid dehydrogenase-isomerase enzyme (3 beta-HSDH). At a similar concentration, P secretion by human chorionic gonadotropin (hCG; 100 mIU/ml) -treated cells was decreased by 68% (P less than 0.001) and therefore, an inhibitory effect of KCZ on the cholesterol side-chain cleavage enzyme (P-450SCC) was assumed. A similar marked inhibitory effect (81%) (P less than 0.001) on T secretion was observed for hCG-stimulated cells given pregnenolone as substrate. The P-450 aromatase was profoundly inhibited (86%) (P less than 0.001) in a reversible manner, by a similar concentration (5 micrograms/ml) of KCZ. These findings suggest that KCZ has the capability to suppress human ovarian steroidogenesis similarly as in testis and adrenal.
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PMID:Effect of ketoconazole on steroidogenic human granulosa-luteal cells in culture. 203 91

Ovine luteal cells were collected and plated 36 h (Day 2) after injection of human chorionic gonadotropin (Day 0) to induce ovulation. Cells were maintained (Days 2-12) in Medium 199 containing 5% calf serum, which was replaced daily. Progesterone secretion was not stimulated (p greater than 0.05) by luteinizing hormone (LH, 10 ng/ml or 100 ng/ml) at any time during culture. However, it was enhanced (p less than 0.05) with a 24-h pulse of dibutyryl adenosine 3', 5'-monophosphate (dbcAMP) during early (2.2-fold stimulation over basal; Days 5,6) or mid- (1.7-fold stimulation over basal: Days 8,9) culture if the pulsing medium contained serum, but not if serum had been withdrawn for 24 h. Continuous exposure of cultures to dbcAMP (2 mM, Days 3-12) resulted in continuously stimulated (p less than 0.05) progesterone secretion (range 1.8- to 4.1-fold stimulation). An increased (p less than 0.05) percentage of cells staining positive for 3 beta-hydroxy-delta 5-steroid dehydrogenase-delta 5, delta 4-isomerase (3 beta HSD) activity were recovered on Day 12 in cultures incubated (Days 3-12) with dbcAMP. Incubation of cultures continuously with prostaglandin F2 alpha (PGF2 alpha) produced dose-dependent inhibition (p less than 0.05) of progesterone secretion. Reduced numbers of 3 beta HSD-positive cells were recovered from these incubations. These experiments demonstrate luteotropic (dbcAMP) as well as luteolytic (PGF2 alpha) effects on ovine luteal cells in long-term culture. This study provides evidence that these cultures will be useful for investigating the development of hormonal regulation of luteal function.
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PMID:Luteotropic and luteolytic responsiveness of ovine luteal cells in long-term culture. 255 79

Two experiments were conducted to examine the effect of treatment with human chorionic gonadotropin (hCG) or ovine luteinizing hormone (LH) on the number and size distribution of steroidogenic luteal cells. In Experiment I, 27 ewes were assigned to one of three groups: 1) hCG (300 IU, i.v.) administered on Days 5 and 7.5 of the estrous cycle (Day 0 = Estrus); 2) LH (120 micrograms, i.v.) administered at 6-h intervals from Days 5 to 10 of the cycle; 3) saline (i.v.) administered as in the LH treatment group. Blood samples were drawn daily from the jugular vein for quantification of progesterone. On Day 10, corpora lutea were collected, decapsulated, weighed, and dissociated into single cell suspensions. Cells were fixed, stained for 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) activity, and the size distribution of 3 beta HSD-positive cells was determined. Treatment with hCG, but not LH, increased (p less than 0.05) concentrations of progesterone in serum and the weight of corpora lutea. Treatment with either hCG of LH increased the proportion of cells greater than 22 micron in diameter and decreased the proportion of cells less than or equal to 22 micron (p less than 0.01). The ratio of small to large luteal cells decreased after treatment with either hCG or LH (p less than 0.05). In Experiment II, 9 ewes were assigned to one of two groups: 1) LH (120 micrograms, i.v.) administered at 6-h intervals from Days 5 to 10 of the estrous cycle, and 2) saline (i.v.) administered as in the LH treatment group.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of luteinizing hormone and human chorionic gonadotropin on cell populations in the ovine corpus luteum. 316 12

Prolactin (Prl), beta 2-adrenergic agents and human chorionic gonadotropin (hCG) are luteotropic in rats, whereas gonadotropin releasing hormone (GnRH) exerts direct inhibitory effects on ovarian steroidogenesis. The present study examined the modulation of the progestin biosynthetic pathway by the luteotropic agents, as well as the actions of GnRH. Rat granulosa cells were primed with follicle-stimulating hormone (FSH) to increase their responsiveness to the luteotropic agents. Subsequent treatment for 2 days with Prl, terbutaline (a beta 2-adrenergic agonist) or hCG stimulated the production of progesterone, 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OH-P), pregnenolone and the activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD). In contrast, treatment with Prl or terbutaline, but not hCG, inhibited 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) activity by decreasing the apparent maximal velocity of the enzyme with no change in its Km value. Concomitant treatment with GnRH inhibited progesterone, but increased 20 alpha-OH-P production stimulated by Prl or terbutaline. These effects were associated with a stimulation of 20 alpha-HSD activity, while neither 3 beta-HSD activity nor pregnenolone biosynthesis was decreased. In contrast, GnRH inhibited progesterone production in hCG-treated cells without affecting 20 alpha-OH-P production. This was associated with an inhibitory effect of GnRH on pregnenolone biosynthesis with no effect upon 3 beta-HSD activity. Thus, Prl and the beta 2-agonist stimulate progesterone production in granulosa cells by increasing pregnenolone production and 3 beta-HSD activity as well as by decreasing 20 alpha-HSD activity, while hCG stimulates progesterone production by increasing pregnenolone production and 3 beta-HSD activity. The inhibitory effect of GnRH on Prl- or terbutaline-stimulated progesterone production appears to result from a preferential increase in 20 alpha-HSD activity, while the GnRH inhibition of hCG-stimulated progesterone production appears to result from a preferential inhibition of pregnenolone production.
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PMID:Regulation of progestin biosynthetic enzymes in cultured rat granulosa cells: effects of prolactin, beta 2-adrenergic agonist, human chorionic gonadotropin and gonadotropin releasing hormone. 613 6


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