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Results for “Progesterone Reductase”

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At least 343 records · Page 19Linked to original sources
PubMed1980

[Experimental torsion of the spermatic cord. Histological and histochemical studies (author's transl)].

In 40 male adult rats on unilateral torsion of the spermatic cord was initiated by operation. In the first group (4 x 5 animals) the testes were removed after 3, 6, 12, 24 hours. The treatment of the animals in the second group (4 x 5 animals) was untwisting of the torsion after 3, 6 12, 24 hours. Three months later both testes were removed. Histological and enzymehistochemical results are as follows: 1. The extend of acute damage to the affected testis depends on the length the torsion lasted. 2. The delay of time of untwisting the testis probably does not influence the degree of later regeneration. 3. Even short duration of torsion of the affected testis results in damage to the contralateral testies.

Acid Phosphatase↗
PubMed1980

[Comparative study of the 3 beta-hydroxy-delta 5-steroid dehydrogenase activity of the mitochondrial and microsomal fractions of human and cat placentas].

Delta 5, 3 beta hydroxysteroid dehydrogenase activity was studied on mitochondrial and microsomal fractions of human and cat placentas. This activity was assessed by measuring the rate of [3H] progesterone formation from [3H] pregnenolone and of [3H] delta 4-androstenedione from [3H] dehydroepiandrosterone (DHA), by a double isotope dilution method. Specific activities measured under initial velocity conditions were similar in both human and cat placentas. However, the kinetics of the reaction with DHA as substrate exhibit a zoological specificity.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Inborn errors of steroid biosynthesis: detection by a new mass-spectrometric method.

A new mass-spectrometric technique relies on ionization during bombardment of the analyte (dissolved in a liquid matrix, usually glycerol) by an atom beam (e.g., Ar0, Xe0). This technique, termed "fast atom bombardment," is particularly useful in the characterization of polar charged molecules. A neutral beam is not essential, and a primary beam of cesium ions has been successfully used to produce spectra equivalent to those obtained by fast atom bombardment. In this communication I report data on the use of both ion and atom primary beams for producing secondary-ion mass spectra of conjugated steroids. In negative-ion spectra produced for steroid glucuronides and sulfates, the ion [M - H]- is invariably the major high-mass peak, and the lack of substantial fragmentation allows assay of relatively complex mixtures if the analytes differ in mass. I describe here the use of secondary-ion mass spectrometry for distinguishing, by urinary steroid analysis, patients with the four enzyme defects that can affect cortisol synthesis: defects in 17 alpha-hydroxylase, 3 beta-hydroxysteroid dehydrogenase/isomerase, 21-hydroxylase, and 11 beta-hydroxylase.

Glucuronates↗
PubMed1980

Action of mitomycin C on testicular steroidogenesis in immature rats.

Treatment with mitomycin C resulted in a decrease in the testicular delta 5-3 beta-hydroxysteroid dehydrogenase level along with a fall of Leydig cell nuclear area. Following the same treatment the significant fall of sex accessory organ weights and testicular accumulation of ascorbic acid and cholesterol were noted. On the basis of above evidence it is suggested that mitomycin C probably suppressed testicular steroidogenesis.

3-Hydroxysteroid Dehydrogenases↗
PubMed1978

[Androgen activity of dysgenesic rats' testis. Histochemical, ultrastructural studies and radioimmunoassay of testosterone].

Androgen activity of rat testis submitted to a radiomimetic, Misulban, during prenatal development has been explored with different technics. Histochemical method shows the presence, in the interstitial cells, of delta5-3beta-hydroxysteroid dehydrogenase (delta5-3beta-HSD), and others enzymes of cellular metabolism, particularly the glucose-6-phosphate dehydrogenase (G6PDH) which is a glucidic enzyme implicated in the specific metabolism of steroidogenesis. From ultrastructural point of view interstitial cells contain the organels proper to steroidogenetic cells (important smooth endoplasmic reticulum, many voluminous mitochondria with tubular cristae). The plasma testosterone concentration measured by radioimmunoassay, confirms the androgenic function of interstitial tissue in dysgenesic testicles.

Animals↗
PubMed1993

Structure and tissue-specific expression of a novel member of the rat 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) family. The exclusive 3 beta-HSD gene expression in the skin.

Structures of cDNA clones encoding three members of the rat 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) family were characterized. To search for potential new types of 3 beta-HSD, rat types I and II 3 beta-HSD cDNAs were used as probes to screen a rat genomic DNA library. Among the clones isolated, one encodes a novel predicted rat 3 beta-HSD isoenzyme, chronologically designated type IV. The corresponding full-length cDNA was thereafter isolated by selective polymerase chain reaction amplification from rat ovary and day-15 placenta cDNA libraries. The rat type IV 3 beta-HSD cDNA encodes a predicted 372-amino acid protein of 41,854 daltons, which shares 90.9, 87.9, and 78.8% sequence identity with rat types I, II, and III proteins, respectively. Ribonuclease protection assay reveals that type IV 3 beta-HSD is the sole 3 beta-HSD mRNA species detectable in the skin and represents the predominant species in the placenta while being also detectable in the ovary and, to a lower degree, in the adrenal gland. Transient expression of type IV cDNA in SW-13 cells indicates 3 beta-HSD activity similar to that of rat type I 3 beta-HSD. The presence of multiple 3 beta-HSD genes should permit differential and tissue-specific regulation of this rate-limiting enzymatic activity essential in the biosynthesis of all classes of steroid hormones in both classical steroidogenic and intracrine peripheral tissues.

Amino Acid Sequence↗
PubMed1994

Effect of lithium chloride on testicular delta 5-3 beta, 17 beta-hydroxy steroid dehydrogenase, acid phosphatase and gametogenesis in Bufo melanostictus.

Injection of lithium chloride at the dose of 200 micrograms/toad/alternate day for 7, 14 and 21 days caused a significant reduction in the activities of testicular delta 5-3 beta, 17 beta-hydroxysteroid dehydrogenase and acid phosphatase enzymes. There was a marked inhibition in spermatogenesis in lithium chloride treated toad for 14 and 21 days of treatment, but 7 days of treatment has no effect.

17-Hydroxysteroid Dehydrogenases↗
PubMed1994

Flavodoxin and NADPH-flavodoxin reductase from Escherichia coli support bovine cytochrome P450c17 hydroxylase activities.

Two soluble flavoproteins, purified from Escherichia coli cytosol and identified as flavodoxin and NADPH-flavodoxin (ferredoxin) reductase (flavodoxin reductase), have been found in combination to support the 17 alpha-hydroxylase activities of heterologously expressed bovine 17 alpha-hydroxylase cytochrome P450 (P450c17). Physical characteristics of the two flavoproteins including absorbance spectra, molecular weights, and amino-terminal sequences are identical with those reported previously for E. coli flavodoxin and flavodoxin reductase. Flavodoxin reductase, possessing FAD as a cofactor, is able to reconstitute P450c17 activities only in the presence of flavodoxin, an FMN-containing protein, and NAD(P)H. Reducing equivalents are utilized more effectively from NADPH than NADH by flavodoxin reductase. E. coli flavodoxin binds P450c17 directly and with relatively high affinity (apparent Ks approximately 0.2 microM) at low ionic strength, as evidenced by a change in spin state of the P450c17 heme iron upon titration with flavodoxin. This apparent spin shift is attenuated at moderate ionic strengths (100-200 mM KCl). In addition, bovine P450c17 binds reversibly to flavodoxin Sepharose in an ionic strength-dependent manner. These data implicate charge pairing as being important for the interaction between flavodoxin and P450c17. We propose that the amino acid sequence similarity between E. coli flavodoxin-flavodoxin reductase and the putative FMN, FAD, and NAD(P)H binding regions of cytochrome P450 reductase provides the basis for the reconstitution of P450c17 activities by this bacterial system.

Aldehyde-Lyases↗
PubMedDate not supplied

[Multiple forms of 3-beta-hydroxy-steroid dehydrogenase of the adrenal glands of rats].

Experiments were conducted on Wistar rats. A study was made of the heterogeneity of 3beta-oxysteroiddehydrogenase (3beta-olDH) of the adrenal glands, the intracellular distribution of its multiple forms and the change of their activity in prolonged (for 3 months) keeping of the animals on a diet devoid of vitamin A. Four 3 beta-olDH fractions were revealed by the method of electrophoresis in polyacrylamide gel in the rat adrenal glands. The principal activity of 3 beta-olDH (68%) was revealed in the endoplasmic reticulum, and only 14%--in the mitochondrial-lysosomal fraction. Hypovitamonsis A caused a reduction of the 3 beta-olDH activity of the adrenal glands, chiefly on account of the 3 beta-olDH-2 fraction.

Adrenal Glands↗