Showing papers on "Hydroxysteroid dehydrogenase published in 1973"
TL;DR: The kinetics of the reaction in the two-phase system as a function of substrate, enzyme concentrations, and pH as well as the equilibrium position were examined.
44 citations
TL;DR: Results showed that 3β-HSD activity is localized on or in membranes of smooth endoplasmic reticulum, in outer compartments of mitochondria, and possibly within smooth endplasmic Reticulum cisternae and intracristal spaces of mitochondia.
Abstract: A procedure for the ultracytochemical demonstration of 3β-hydroxysteroid dehydrogenase (3β-HSD) is described and the results for the localization of this enzyme in the lutein cells of the rat corpus luteum are presented.
23 citations
TL;DR: Steroid substrates did not protect 20β-hydroxysteroid dehydrogenase against acid inactivation or affect enzyme fluorescence and it was concluded that under the experimental conditions little steroid was bound to the enzyme in the the absence of coenzyme.
23 citations
TL;DR: Rates of 3α, 5α- and 20α-reduction of progesterone have been measured in homogenates of rat uterus at varying stages of gestation and removal of endometrium by scraping indicated this increase was limited to theendometrium.
Abstract: Rates of 3α-, 5α- and 20α-reduction of progesterone have been measured in homogenates of rat uterus at varying stages of gestation. The activity of 5α-reductase was low at days 14-16 and increased 2.5-fold before the end of pregnancy. The activity of 20α-hydroxysteroid dehydrogenase increased 3.5-fold during the latter half of gestation. Removal of endometrium by scraping indicated this increase was limited to the endometrium.(Endocrinology92: 624, 1973)
14 citations
TL;DR: An improved method for the demonstration of 3β and 17β hydroxysteroid dehydrogenase (HSD) in human testis has been devised and maintains good cellular morphology with little loss of enzymatic activity.
Abstract: An improved method for the demonstration of 3β and 17β hydroxysteroid dehydrogenase (HSD) in human testis has been devised The procedure maintains good cellular morphology with little loss of enzymatic activity The significant features of the procedure are as follows:
1
Tris-maleate buffer made up in Tyrode's balanced salt solution is employed in all steps from pre-freezing infiltration through fixation
2
Dimethylsulfoxide is used to protect from freezing artifacts, to enhance substrate and tetrazolium salt penetration, and to increase substrate solubility
3
A pre-incubation soak in the medium buffer system, dimethyl-sulfoxide, polyvinyl pyrrolidone and dimethylformamide, is used and a pH of 74 to 75 is maintained to limit false positive reaction
4
Potassium cyanide is employed in the medium to enhance the formation of reaction product
5
Polyvinylpyrrolidone is used in the pre-incubation and incubation media to reduce destruction of tissue morphology
6
Several steroid substrates for both 3β and 17β-HSD may be used
12 citations
TL;DR: A placental organ culture system was designed to establish whether changes in placental villi induced by an antecedent period of hypoxia could be reversed by re‐oxygenation, and reversal was achieved, but was time‐limited.
5 citations
TL;DR: It is demonstrated that the ovaries of immature mice devoid of corpora lutea are capable of converting androstenedione to testosterone and oestradiol-17β to oestrone indicating the presence of 17β-hydroxy steroid dehydrogenase in such tissue.
4 citations
TL;DR: Endogenous and radioactively-labelled exogenous pregnenolone was metabolized in adrenal homogenates of the rabbit, the cow and the ewe when kept at temperatures between 0 and+6°C, a process that could be prevented by the addition of cyanoketone, an inhibitor of the enzyme 5-ene-3β -hydroxysteroid dehydrogenase complex.
4 citations
Journal Article•
2 citations
Journal Article•
1 citations
TL;DR: Administration of 20 β-hydroxysteroid dehydrogenase from Streptomyces hydrogenans to rats either intravenously or intraperitoneally results in decreases in serum progesterone, similar in diestrous and proestrous rats.