Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0265264 (HOS)
 1,119 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper describes for the first time the presence of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity in osteoblast-like cells and investigates its characteristics. 3beta-HSD activity was detected by the formation of androstenedione from [3H]dehydroepiandrosterone (DHEA) in whole cell assays of human osteoblast-like cells, HOS and MG-63. The radiolabeled product, androstenedione, was purified by thin-layer chromatography and identified by recrystallization on admixture with authentic androstenedione to show constant specific activities. The apparent Michaelis constant (Km) for DHEA in HOS was found to be 9.9 microM and that in MG-63 was 80.4 microM. The expression of the 3beta-HSD messenger ribonucleic acid in HOS and MG-63 was demonstrated through a reverse transcription-polymerase chain reaction. The PCR products were confirmed by Southern blot analysis. The existence of 3beta-HSD in osteoblast-like cells indicates that these cells convert delta5 androgens into more biologically active delta4 3-keto steroids. These results, together with the demonstration of other steroid converting enzyme systems, suggest that the osteoblast cells play an important role in facilitating hormonal action in bone tissue.
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PMID:3Beta-hydroxysteroid dehydrogenase activity in human osteoblast-like cells. 962 1

Sodium fluoride (NaF) administered orally to adult male rats at a dose level of 4.5 ppm and 9.0 ppm for 75 days caused significant decrease in the body weight, brain index and testicular index. A significant decrease in sperm count, sperm motility, sperm viability and sperm function (HOS positive) with increased sperm abnormalities was also observed in NaF-exposed male rats. The activity levels of testicular steroidogenic marker enzymes 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) were significantly decreased in NaF-treated rats indicating decreased steroidogenesis and in turn spermatogenesis in rats exposed to NaF.
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PMID:Exposure to high fluoride concentration in drinking water will affect spermatogenesis and steroidogenesis in male albino rats. 1598 65

The present study was designed to assess potential reproductive toxicity caused by fentin and fenbutatin in the mice. Adult male mice received i.p. injections of fentin hydroxide and fenbutatin oxide at a dose of 0, 10 or 25 microg/kg body weight on 1st, 3rd and 5th day of experimentation. Mice were sacrificed on day 25 and analyzed for spermatogenesis and steroidogenesis. A significant decrease in epididymal sperm count, sperm motility, sperm viability and sperm function (HOS coiling) were observed in experimental mice when compared with controls. The decrease in sperm quantity and quality was significant in the 25 microg/kg group than that in the control group. The activity levels of testicular steroidogenic enzymes, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) were significantly decreased in treated mice indicating decreased steroidogenesis after organotin compounds administration. The levels of serum testosterone decreased with an increase in follicle stimulating hormone and luteinizing hormone in experimental mice when compared to control mice. The results suggest that fentin and fenbutatin cause impairment of spermatogenesis through the inhibition of testosterone production.
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PMID:Reduction of spermatogenesis and steroidogenesis in mice after fentin and fenbutatin administration. 1680 47