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Showing papers on "Hydroxysteroid dehydrogenase published in 1968"


Journal ArticleDOI
TL;DR: Kinetic and spectral analyses of 20β-hydroxysteroid dehydrogenase indicate that this enzyme mediates an Ordered BiBi reaction with cofactor binding first and has a higher affinity for NADH than for NAD + .

38 citations


Journal ArticleDOI
TL;DR: A method to estimate semiquantitatively the activity of HSD enzymes and is described in detail, which depends on demonstrating NAD‐dependent hydroxysteroid dehydrogenase by using nitro‐BT as a hydrogen acceptor leading to the deposition of blue diformazan particles.
Abstract: SUMMARY. A method has been established to estimate semiquantitatively the activity of HSD enzymes and is described in detail. In the main, the method depends on demonstrating NAD-dependent hydroxysteroid dehydrogenase by using nitro-BT as a hydrogen acceptor leading to the deposition of blue diformazan particles. The latter are then counted in a sebaceous gland by means of a Wild M20 microscope with a drawing tube attachment. The method is limited in use as a semi-quantitative comparison of enzyme activity in a few adjacent sections of a sebaceous gland.

22 citations


Journal ArticleDOI
TL;DR: The effects of various factors on the histochemical demonstration of 3β‐hydroxysteroid dehydrogenase activity in human skin were examined by a semiquantitative technique of granule counting.
Abstract: SUMMARY.— The effects of various factors on the histochemical demonstration of 3β-hydroxysteroid dehydrogenase activity in human skin were examined by a semiquantitative technique of granule counting. The optimum concentration of DHA was found to be 0·1 mg./ml. and of NAD 0·3 mg./ml. Vitamin K and nicotinamide enhanced the histochemical demonstration of the enzyme whereas cyproterone and cyproterone acetate inhibited the reaction.

18 citations


Journal ArticleDOI
TL;DR: The combination of the total number of endocrine-active cells and the quantity of the enzymes per cell seem to determine the clinical effect of the steroids produced.

14 citations


Journal ArticleDOI
TL;DR: The isolation and identification of steroid metabolites is reported after the incubation of progesterone-4-14C and Δ6-pregnenolone- 4- 14C with quartered mouse adrenal glands and with added NADPH and SU-4885, and DOC was formed but corticosterone was not isolated.
Abstract: The isolation and identification of steroid metabolites is reported after the incubation of progesterone-4-14C and Δ6-pregnenolone-4-14C with quartered mouse adrenal glands and with added NADPH (10−4m) and SU-4885 (10−4m). The ring-A reduced metabolites of either progesterone-4 14C or Δ5-pregnenolone-4-14C included: 5β-pregnane-3α,20α-diol, 5β-pregnane-3, 20-dione, and 3β-hydroxy-5α-pregnane-20-one. With Δ6-pregnenolone-4-14C as substrate, C20-reduced intermediates were detected within 10 min, 5-pregnane-3β,20α-diol and 20α-hydroxy- 4-pregnene-3-one. Under the conditions of these incubations and in the presence of NADPH, the reduction to the 20α-hydroxyl occurred prior to the conversion of the Δ5-3β-hydroxyl to the Δ4-3 ketone. DOC was not found in the control incubations. In the presence of SU-4885, DOC was formed but corticosterone was not isolated. A thorough search for either C-21-17α-hydroxylated or C-19 metabolites was not successful. The role of the various hydroxysteroid dehydrogenases in the form...

14 citations


Journal ArticleDOI
TL;DR: In this article, the quadro enzimatico dei corpi lutei (C.L.) was investigated in relation with 20α-idrossisteroide deidrogenasica.
Abstract: E stato studiato il quadro enzimatico dei corpi lutei (C.L.) di recente formazione nelle ovaie di ratte ipofisectomizzate. In particolare si e constatato come la comparsa dell'attivita 20α-idrossisteroide deidrogenasica non sia impedita dall'ipofisectomia. Si suggerisce la possibilita che l'ipofisi eserciti una azione inhibitrice sulla comparsa di questo enzima.

4 citations


01 Jan 1968
TL;DR: The occurrence of JB-HSD activity in the adrenala of the chick embryo lead to the conclusion that the adrenocortical cells have the capacity tor steroid hormone syntheSis b.Y stage 23 (day 4).
Abstract: This investigation concerned itself primarily with the development ot adrenal d-JB-hydr0JE;Y8teroid dehydrogenase (d-3B-HSD) aotivity and the effects of exogenous ACTH on this activity in the embryonic chicken. A prel1m1nary investigation was wxiertaken to determine the norul development of the adrenal of brown and white Legborn chick embryos. Since chronological and morphological ages are not alvays clo.el3 oorrelated, morphologi-cal chara cterietics. as .. tabl1shed 1>7 Hamburger and Hamilton (, 51) , were employed to determine developmental age. There wae no s1gn1ticant difference in development ot the adrenal glands in the two yari.ties ot Leghorn studied. Only minor variations between our observations and those ot other investigators were observed. A moditication ot the histochemical technique of Levy and ooworkers (t.59 was used to detel"'1'ld.ne d.JB-HSD aotivity. Such BoUnty was observed in the primordial adrenocortical cells ot stage 2J (day 4) brown and white Leghorn embl7Os. There was a s1gn1ticant difterence in the development of ~.s -JB-HSD activity between brown and white Leghorn embryos. DUferences in the intensity of the enzyme reaction when sections ot the same embryo were incubated with the two substrates, dehydroepiandrosterone (DHA) and pregnenolone, sugs gest the possibility of two enzyme" rather than one. Brown Leghorn embryos ot stages 2J, 23-24 and 24 showed an increase in enzyme activity after the administration of porcine ACTH. The time interval between the last ACTH injection and the time of sacrifice was found to b. sign1f'icant. Eabryoa sacrificed prior to three hours following injection exix hibited no increase in activity aa did those sacrificed between 21 and 46 hours following injection. A algn1.f'lcant increase in activity was observed in the adrenals ot embryos sacrificed three to 11 hours after the final injection. The occurrence of ,6,..5_JB-HSD activity in the adrenala of the chick embryo lead to the conclusion that the adrenocortical cells have the capacity tor steroid hormone syntheSis b.Y stage 23 (day 4). Treatment of such embryos with exogenous ACTH resulted in an increase in adrenal ,6,..5 -JB-HSD activity indioating that the embryonic chicken adrenal is susceptible to ACTH stimulation in ita early stages ot development.

2 citations