Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.12.7.2 (hydrogenase)
3,522 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adrenal cortisol secretion is greater in female than male guinea-pigs and declines with maturation in animals of both sexes. In an attempt to determine the intra-adrenal mechanisms responsible for age and sex influences on corticosteroid output, adrenocortical enzyme activities were compared in sexually immature (3 weeks) and mature (17 weeks) animals. Adrenal mitochondrial protein concentration decreased with maturation in male and female guinea-pigs. 11beta-Hydroxylase activity in adrenal mitochondria was also lower in mature than immature guinea-pigs but greater in males than females. Neither mitochondrial cytochrome P-450 concentration nor cholesterol side-chain cleavage activity varied with age or sex. Adrenal microsomal protein concentration and 21-hydroxylase activity were similar in male and female guinea-pigs of the same age but far greater in mature than immature animals. Microsomal cytochrome P-450 concentration was unaffected by age or sex. Adrenal delta4-steroid (cortisol) hydrogenase activity increased with maturation in both male and female guinea-pigs and was higher in males than females. These observations indicate that cortisol secretion, as modified by age and sex, correlates closely with adrenal steroid reductive but not oxidative metabolism, suggesting that changes in delta4-hydrogenase activity are responsible, at least in part, for the decline in adrenal secretion during maturation in guinea-pigs.
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PMID:Changes in adrenocortical function in male and female guinea-pigs during maturation. 18 Feb 25

A crude human hypophyseal extract (HE), as well as human growth hormone (GH), ovine prolactin (PRL) and commercial preparations of ACTH, TSH, pregnant mare's serum gonadotrophins (PMS) and chorionic gonadotrophin (CG) were tested for their ability to induce the activities of cytoplasmic 17 beta-hydroxysteroid dehydrogenase and microsomal delta 4-5alpha-hydrogenase and to repress the activities of microsomal 3alpha- and 3beta-hydroxysteroid dehydrogenases in the liver of hypophysectomized rats. The activity of 17beta-hydroxysteroid dehydrogenase was not affected by any of the administered hormones. For the other enzymes, only PRL was effective in causing changes in the activities; the repressive effect on 3alpha-hydroxysteroid dehydrogenase activity was highly significant (P less than 0.001). These results indicate that PRL is involved in the regulation of at least some of the enzyme activities of hepatic steroid hormone metabolism.
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PMID:Regulation of the activities of the enzymes involved in the metabolism of steroid hormones in rat liver: the effect of administration of anterior hypophyseal hormones and gonadotrophin preparations to hypophysectomized rats. 18 36

Spironolactone administration (50 mg/kg/day for 3 days) to make guinea pigs decreased cortisol production by adrenal slices in vitro. Adrenal microsomal and mitochondrial cytochrome P-450 levels were also decreased after treatment with spironolactone. The decline in adrenal cytochrome P-450 content was accompanied by decreases in microsomal 21-hydroxylase and mitochondrial cholesterol side-chain cleavage and 11beta-hydroxylase activities. Activities of other adrenal enzymes, such as delta4-hydrogenase and NADPH-cytochrome c reductase, were unaffected by spironolactone treatment. Cortisone administration to guinea pigs failed to mimic the effects of spironolactone on adrenal function, which indicates specificity of spironolactone action and excludes inhibition of adrenocorticotropin secretion as a mode of action. Addition of spironolactone to isolated adrenal mitochondria or microsomes produced type I spectral changes with spectral dissociation constants similar to those for endogenous steroid substrates. Spironolactone, in vitro, inhibited 11beta- but not 21-hydroxylase activity. The results indicate that spironolactone administration diminishes the activity of adrenal mitochondrial as well as microsomal cytochrome P-450-containing enzymes, resulting in a fall in corticosteroid output.
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PMID:Mechanism of action of spironolactone on adrenocortical function in guinea pigs. 97 70

The metabolism of [4-14C]progesterone in the parotid salivary glands of nonpregnant female, pregnant female and male rats were investigated in vitro. The metabolic activity of the male rats was significantly lower than in either of the female groups. The pregnant group was metabolically more active than the nonpregnant female group, but his differences was not statistically significant. I homogenates and soluble fractions the main metabolite was 20-alpha-hydroxy- 4-pregnen-3-one in female rats. In male rats the main metabolites were 20-alpha-hydroxy-4- pregnen-3-one and 3-alpha-hydroxy-5-alpha-pregnan-20-one in homogenates and 20-alpha-hydroxy-4- pregnen-3-one in soluble fractions. In the microsomal fractions of both sexes polar compounds predominated. The results indicated the presence of at least the following progesterone metabolizing enzymes in art parotid salivary glands; 3-alpha-, 3-beta-, 20-alpha- and 20-beta-hydroxysteroid dehydrogenase, 5-alpha-and 5-beta-steroid hydrogenase and 17-alpha-steroid hydroxylase activities. Ind the homogenates and soluble fractions of female rats 20-alpha-hydroxysteroid dehydrogenase activity was significantly higher than in males.
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PMID:Progesterone metabolism by major salivary glands of rat--II. Parotid gland. 227 46

The metabolism of progesterone by the submandibular and sublingual salivary glands of female (nonpregnant and pregnant) and male rats was studied. The metabolism was in both sexes significantly greater in submandibular than in sublingual glands. Sex differences were not seen in sublingual glands but less metabolism was found in homogenates and microsomal fractions of female (nonpregnant and pregnant) submandibular glands compared to that of males. The metabolism did not differ between pregnant and nonpregnant female rats. The metabolites were mainly 5 alpha-pregnane-compounds. On the basis of the metabolites identified it can be concluded that rat submandibular and sublingual glands contain at least 3 alpha-, 3 beta-, 20 alpha- and 20 beta-hydroxysteroid dehydrogenase, 5 alpha- and 5 beta-steroid hydrogenase and 17 alpha-steroid hydroxylase activity. 5 alpha-steroid hydrogenase activity was significantly higher in all preparations of male submandibular glands than in females. In sublingual glands some enzyme activities showed pregnancy-related decreased.
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PMID:Progesterone metabolism by major salivary glands of rat--I. Submandibular and sublingual glands. 236 33

The metabolism of testosterone by experimental granulation tissue, fibroblasts and the oral mucosa of rats of both sexes was studied. The experimental granulation tissue was produced by implanting viscose-cellulose sponges beneath the dorsal skin of female and male rats for 21 days. The granuloma capsules, fibroblasts in the sponges and the oral mucosae were homogenated. Mitochondrial, microsomal and soluble fractions were incubated with [4-14C]testosterone and NADPH for 30 min at pH 7.4 and 37 degrees C. The metabolites were identified with column and TLC and radioautography and quantified with liquid scintillation counting. The experimental granulation tissue and fibroblasts of both sexes showed less activity in metabolizing testosterone than the gingival tissue. The tissues were shown to contain 3 alpha-, 3 beta- and 17 beta-hydroxysteroid dehydrogenase and 5 alpha- and 5 beta-steroid hydrogenase activities. The activities of the enzymes in the oral mucosae were higher than in the experimental granulation tissue and fibroblasts.
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PMID:Role of granulation tissue and fibroblasts in gingival testosterone metabolism in the rat in vitro. 379 46

Hepatocyte nodules that persist throughout chemical carcinogenesis are linked to carcinomas both as one site at which hepatomas are seen to arise and as a tissue which shows more than a dozen significant protein changes also found in liver cancers. In view of the differential stimulus to growth of these persistent nodules by progesterone, progesterone metabolism and binding to the microsomes of nodules and hepatomas were studied. Progesterone metabolizing enzyme activities in nodule microsomes showed striking shifts with a 42% decrease in 16 alpha-hydroxylase activity and a 2- to 3-fold increase in 6 beta-hydroxylase activity compared to control levels. Hepatomas had a dramatic 20-fold increase relative to nodules or controls in the reductive pathway for progesterone metabolism as measured by delta 4-5 alpha-hydrogenase activity. The rate and saturation of the specific binding of progesterone to microsomes of nodules and liver cancers were significantly decreased when compared either to the tissue surrounding the nodules or to their respective control microsomes. This change in progesterone binding of nodular microsomes may relate to an altered balance of progesterone content and its metabolites in the nodular cells or to alterations in the microsomal membrane binding site. The functional significance of reduced binding of progesterone for liver carcinogenesis is thus open to further inquiry.
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PMID:Changes in progesterone binding and metabolism in liver microsomes from persistent hepatocyte nodules and hepatomas in male rats. 394 Feb 12

[4-14C]Progesterone was incubated with homogenate and mitochondrial, microsomal and soluble fraction preparations of healthy and inflamed gingiva from human subjects of both sexes. The subcellular preparations were supplemented with an NADPH-regenerating system and incubated for 2 h at pH 7.4 and 37 degrees C. The metabolites were identified by column, multiple TLC and radioautography and quantified with liquid scintillation counting. In inflamed tissue the metabolic activity was higher than in healthy gingiva. On the basis of the identified metabolites it can be concluded that the human gingiva of both sexes contains marked 3 alpha-, 3 beta- and 20 alpha-hydroxysteroid dehydrogenase, delta 4-5 alpha- and delta 4-5 beta-steroid hydrogenase activities, and less 20 beta-hydroxysteroid dehydrogenase activity.
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PMID:Metabolism of progesterone by healthy and inflamed human gingiva in vitro. 409 11

We have examined the effect of recent onset diabetes on several aspects of hepatic microsomal metabolism in both streptozotocin (STZ)-induced and spontaneously diabetic BioBreeding (BB) male and female Wistar rats. Differential alterations of the diabetic state on hepatic microsomal enzyme activities were observed. Female diabetic rats exhibited no change in benzo [a]pyrene (BP) hydroxylase activity, a decrease in testosterone delta 4-hydrogenase, and an increase in aniline hydroxylase. On the other hand, male diabetic rats demonstrated a decrease in hepatic BP hydroxylase activity, no change in testosterone delta 4-hydrogenase, and an increase in aniline hydroxylase. Insulin treatment corrected these effects. No change in kidney BP hydroxylase activity was apparent in either female or male diabetics. There were no marked differences between the chemically induced and genetic models of diabetes with respect to the metabolism studies. Serum testosterone levels were significantly lower than control in male BB diabetics, whereas no change was apparent in female diabetics. Light microscopy and serum insulin determinations indicated that the spontaneously diabetic animals we examined were not severely diabetic. From electrophoresis of hepatic microsomal proteins we determined that spontaneous diabetes of short duration does alter the protein distribution in the cytochrome P-450 region. We conclude that the acute effects of STZ-induced and spontaneous diabetes on hepatic microsomal metabolism are quantitatively and qualitatively similar, despite probable differences in etiology of the diabetic state.
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PMID:Differential effects of diabetes on microsomal metabolism of various substrates. Comparison of streptozotocin and spontaneously diabetic Wistar rats. 634 6

Diabetes-induced alterations in heme and hemoproteins, as well as its relationship to drug-mediated induction of ALA Synthase (ALA-S), were examined in female Sprague-Dawley rats. Animals were rendered diabetic by a single i.v. injection of streptozotocin (STZ, 65 mg/kg) and measurements were made at various times after treatment. The basal levels of the key enzymes involved in heme synthesis, ALA-S and ALA-dehydratase (ALA-D), were decreased about 36% and 54%, respectively, 44-46 days after diabetes induction. Furthermore, the catabolism of heme that occurs via microsomal heme oxygenase progressively decreases in activity during the course of diabetes, and reaches 69% of control in 90-day diabetic animals. The basal levels of heme, cytochromes P-450 and b5 were elevated about twofold in diabetic rats as compared with their corresponding control values. The activity of benzo(a)pyrene hydroxylase in diabetic rats was also increased in proportion to the microsomal content of cytochrome P-450. In contrast, delta 4-hydrogenase, the rate-limiting enzyme in corticosterone metabolism, exhibited a 35-65% decrease in activity throughout the experimental period. Tryptophan pyrrolase activity (total, holo-, and apoenzyme) was elevated about 2.5-fold in STZ diabetic rats. In vivo insulin therapy of diabetic animals antagonized the effect of the diabetic state on the above measured parameters. Treatment with aminoglutethimide resulted in about a twofold elevation in ALA-S activity in control as well as chronically diabetic rats. However, a similar stimulatory response in ALA-S activity to CoCl2 administration was observed only in control or insulin-treated diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Diabetes-induced metabolic alterations in heme synthesis and degradation and various heme-containing enzymes in female rats. 660 90


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