Showing papers on "Hydroxysteroid dehydrogenase published in 1970"
TL;DR: The stereochemistry of hydrogen transfer from NADPH in the conversion of Δ4-3-oxosteroid 5β-reductase and 3α-hydroxysteroid dehydrogenase was studied and the hydrogen transferred from the pyridine nucleotides was the 4A-hydrogen.
Abstract: The stereochemistry of hydrogen transfer from NADPH in the conversion of Δ4-3-oxosteroids into 3-oxo-5β-steroids and from NADH and NADPH in the conversion of 3-oxo-5β-and 3-oxo-5α-steroids into 3α-hydroxysteroids, catalyzed by rat liver Δ4-3-oxosteroid 5β-reductase and 3α-hydroxysteroid dehydrogenase, respectively, was studied with C19-, C21-, C24-, and C27-steroids. In all cases, the hydrogen transferred from the pyridine nucleotides was the 4A-hydrogen.
36 citations
30 citations
TL;DR: The results indicate that 20α-HSD is not an important enzyme in ovarian progesterone metabolism in the bitch, while Δ 5 -3 β - HSD is very active in luteal, follicular, and stromal cells of the cortex.
25 citations
TL;DR: The intensity of enzyme activity in the different cells of the ovary varied according to the age of the bird and its environmental lighting conditions, and was correlated with increases in ovarian weight in birds exposed to 16L:8D but not to 8L:16D.
21 citations
TL;DR: A comparison between the human foetal and adult pattern of enzyme activity has been drawn, and the significance of the results discussed.
Abstract: SUMMARY.— Specimens of skin of 25 human foetuses from 8 to 32 weeks gestation were incubated to demonstrate the presence of hydroxysteroid dehydrogenases by histochemical methods. 17β-HSD was demonstrated at 16 weeks gestation, when fully differentiated sebaceous glands were first visualized. 3β-HSD and 16β-HSD were recognized at a later stage. These enzymes were found only in sebaceous glands and in no other appendages. A comparison between the human foetal and adult pattern of enzyme activity has been drawn, and the significance of the results discussed.
5 citations
Journal Article•
4 citations
TL;DR: Portions of frog skin from different regions were examined histochemically for hydroxysteroid dehydrogenase activity and two basic gland types were seen — those possessing activity, thought to be the poison glands, and the mucous glands which were unable to utilize the Hydroxysteroids.
Abstract: Portions of frog skin from different regions were examined histochemically for hydroxysteroid dehydrogenase activity. Two basic gland types were seen — those possessing activity, thought to be the poison glands, and the mucous glands which were unable to utilize the hydroxysteroids.
3 citations
TL;DR: It was evident that ACTH, although it also stimulated the synthesis of microsomal protein, could not fully explain the effects of cyano-ketone, and exposure to a high level of ACTH for 4 hr or 4 days seemed to exert less net effect on mitochondrial protein.
Abstract: In experiments reported recently (J Clin Endocr 29: 539, 1969) there were changes in the synthesis of guinea pig adrenal micro-somal proteins after in vivo exposure to an inhibitor of 3β-hydroxysteroid dehydrogenase, 2α-cyano-4,4,17α-trimethylandrost-5-en-17β-ol-3-one (cyano-ketone), for 4 days. It was evident that ACTH, although it also stimulated the synthesis of microsomal protein, could not fully explain the effects of cyano-ketone. This report presents data on proteins of mitochondrial fractions obtained in the same experiments. The protein content of the mitochondrial fraction and protein radioactivity after 4 hr exposure to l-leucine-(3H) was increased after cyano-ketone as it had been in the microsomal fraction. Exogenous ACTH again could not explain the effect of the inhibitor on the synthesis of total mitochondrial proteins or protein fractions separated by acrylamide gel electrophoresis. Exposure to a high level of ACTH for 4 hr or 4 days seemed to exert less net effect on mitochondrial protein...
2 citations
Journal Article•
1 citations