Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Imipramine administration (50 mg kg-1, i.p.) to Sprague-Dawley male rats (240-290 g) 6 or 10 h after CCl4 (1 ml kg-1, i.p.) partially prevents liver necrosis induced by the hepatotoxin. When imipramine is given 30 min before CCl4, it inhibits in part the CCl4-induced lipid peroxidation and the covalent interactions of reactive metabolites with microsomal lipids or proteins and partially prevents CCl4-induced cytochrome P-450 destruction, but not glucose 6 phosphatase activity depression. Imipramine administration prior to CCl4 does not modify levels of the hepatotoxin reaching the liver or the body temperature of CCl4 treated animals. Early preventive effects of imipramine on cytochrome P-450, might be attributed to inhibition of covalent interactions of reactive metabolites. The hypothesis that imipramine exerted late preventive effects by interfering with calcium deleterious effects or by modulation of protein and phospholipid synthesis or degradation is analyzed.
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PMID:Imipramine prevention of carbon tetrachloride-induced liver necrosis at late states of the intoxication process. 302 54

The protective effect of SKF 525-A on the suppression of cytochrome P-450 content and monooxygenase activities by treatment with CoCl2 and polyriboinosinic acid-polyribocytidylic acid [poly(I.C] was compared as a part of studies of suppression of drug metabolizing enzymes by interferon inducers. Induction of heme oxygenase activity by CoCl2 and poly (I.C) was not altered by simultaneous treatment with SKF 525-A. Depression of cytochrome P-450 content and benzphetamine N-demethylase activity by treatment with CoCl2 was prevented by co-treatment with SKF 525-A. This effect was explained by the prevention of release of heme from cytochrome P-450 by forming metabolic intermediate complexes with metabolites of SKF 525-A. On the other hand, poly(I.C) significantly suppressed P-450 content and benzphetamine N-demethylase and benzo [a] pyrene hydroxylase activities, even under simultaneous treatment with SKF 525-A. This inhibition by poly (I.C) was accompanied by weak staining of proteins corresponding to cytochrome P-450 in SDS gel electrophoresis. In addition, the activity of non-heme enzyme, 4-hydroxybiphenyl glucuronyltransferase, was suppressed by treatment with poly (I.C) but not by CoCl2-treatment. These findings strongly suggested that, unlike CoCl2, poly (I.C) suppressed cytochrome P-450 content and monooxygenase activities due to decreased synthesis or increased degradation of the apoprotein of cytochrome P-450 with slight contribution of the induced heme oxygenase.
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PMID:Effect of co-administration of interferon inducer, polyriboinosinic acid-polyribocytidylic acid, with SKF 525-A on hepatic drug metabolizing enzymes of rats. 309 97

The hepatic monooxygenase system was studied in hypophysectomized female rats infused for 5 days with ovine growth hormone (GH). At 7.5 micrograms.h-1 GH decreased the total cytochrome P-450 by 16%; at 10 micrograms.h-1 it reduced both cytochrome P-450 (31%) and the activity of ethylmorphine demethylase (31%). GH did not alter the activities of NADPH cytochrome c reductase or aniline hydroxylase. The lower GH dose decreased the amount of fast- and slow-turnover P-450 by 11 and 38%, respectively, while the higher dose decreased both by 49%. The loss of demethylase activity therefore correlates with the loss of fast-turnover P-450. This component is relatively more abundant in the female (fast: slow turnover of 4.3) than the male (fast:slow turnover of 2.5). GH did not affect the half-lives of the P-450 components, suggesting that it decreases their synthesis. The P-450 concentration in microsomes from GH-treated animals did not increase after incubation with hemin, suggesting that in vivo the hormone does not lower P-450 synthesis via depression of heme. Puromycin mimicked the effect of GH and when given with the hormone their effects on the P-450 levels were multiplicative (p less than 0.05), suggesting different modes of action and that GH does not decrease P-450 by acting at translation.
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PMID:Growth hormone depresses ethylmorphine demethylase activity: correlation with decreased levels of fast-turnover cytochrome P-450 in hypophysectomized female rats. 314 99

Mice bearing the S-180 sarcoma displayed a depression of liver catalase and cytochrome P-450-dependent enzymes (ethoxycoumarin deethylase, ED) from day 6 following tumor implantation. Injection of serum obtained from tumor-bearing mice into normal mice caused depression of liver ED suggesting that a circulating factor was involved. Tumor-bearing mice did not show any significant change in serum triglycerides and food intake. By contrast, injection of endotoxin, interleukin-1 (IL-1) or tumor necrosis factor (TNF) caused not only a depression in liver ED but also a marked increase in serum triglycerides. To study the possible analogies between cancer-associated circulating factor and monokines, we studied the effect of dexamethasone (a known inhibitor of monokine synthesis) on liver ED activity in tumor-bearing mice. Dexamethasone (DEX) treatment increased (up to 60%) liver ED activity in tumor-bearing mice. We conclude that: (i) a circulating factor is involved in cancer-associated ED depression; (ii) that this mediator is not necessarily identical to TNF or IL-1 and (iii) that DEX reverses the depression of liver ED in cancer, possibly by inhibiting the synthesis, or the effects, of this factor.
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PMID:Depression of liver drug metabolism in sarcoma-bearing mice. Evidence for a circulating factor and dissociation from lipolytic activity. 326 84

The potentials of octachlorostyrene (OCS) and hexachlorobenzene (HCB) to induce liver microsomal ethoxyphenoxazone deethylation (an indicator of induction of 3-methylcholanthrene and beta-naphthoflavone-like cytochrome P-450 monoxygenase activity) and cause porphyria in male C57BL/6 and C57BL/10 mice and female F344 rats were compared. Ethoxyphenoxazone deethylation was induced much more by HCB than by OCS in both of these strains of mice (although neither OCS nor HCB greatly induced deethylation in the DBA/2 strain). In rats ethoxyphenoxazone deethylase was induced 26-fold by HCB but only four-fold by OCS, whereas dealkylation of pentoxyphenoxazone (an indicator of phenobarbital-like induction) increased 43- and 36-fold, respectively. Both chemicals were poor inducers of dealkylation of pentoxyphenoxazone in mice. When fed HCB continuously but not when given OCS, C57BL/6 and C57BL/10 mice (both after pretreatment with iron) and F344 rats developed porphyria with a depression of hepatic uroporphyrinogen decarboxylase activity. The results illustrate that in these species OCS and HCB cannot be considered as equally efficient agents for inducing ethoxyphenoxazone deethylation or causing porphyria. If these effects are mediated through binding to the aromatic hydrocarbon responsiveness (Ah) receptor, HCB would appear to have a much greater affinity than OCS despite the face that neither chemical possesses a structure currently considered to be necessary for efficient binding.
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PMID:Distinction between octachlorostyrene and hexachlorobenzene in their potentials to induce ethoxyphenoxazone deethylase and cause porphyria in rats and mice. 327 68

The study of the influence of the age of the animals (13 to 53 weeks) on the rate of ethanol metabolism in vivo and the total activity of liver alcohol dehydrogenase and microsomal ethanol oxidizing system showed a progressive decline with age. These effects were observed concomitantly with a diminution in the content of cytochrome P-450 and microsomal functions related to oxidative and free-radical mediated reactions, namely, NADPH oxidase activity, NADPH-dependent oxygen uptake and NADPH-or t-butyl hydroperoxide-induced chemiluminescence. It is concluded that ageing is accompanied by a diminution in the total oxidative activity of the liver tissue, which would explain the depression in basal and ethanol-induced lipid peroxidation found in the oldest group of rats studied.
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PMID:Age-dependent changes in in vivo ethanol metabolism and in the activity of hepatic enzymes involved in ethanol oxidation and microsomal functions. 334 70

Incubation of 25-hydroxyvitamin D3 with kidney cortex mitochondria from 1,25-dihydroxyvitamin D3-treated guinea pigs resulted in the formation of 23,25-dihydroxyvitamin D3 as the major product. The identity of the product was verified by g.c.-m.s. and quantification was performed by h.p.l.c. The rates of the reaction were in the range 1.0-1.8 pmol/min per mg of mitochondrial protein (at 37 degrees C), which were 5-10 times the rates of formation of 24,25-dihydroxyvitamin D3. In mitochondrial preparations from untreated guinea pigs, the rate of 23-hydroxylation was below detection limit (0.02 pmol/min per mg of mitochondrial protein). Fasting the animals for 24 h induced the 23-hydroxylase almost as efficiently as treatment with 1,25-dihydroxyvitamin D3, with a concomitant depression of the 1 alpha-hydroxylase. The 23-hydroxylase reaction required oxidizable substrate, was decreased by low O2 partial pressures and inhibited by CO or the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone. It was stimulated by the respiratory-chain inhibitors rotenone, antimycin A and KCN. These results indicate that the guinea-pig renal mitochondrial 23-hydroxylase is a cytochrome P-450 and that the reducing equivalents are primarily supplied by NADPH via the energy-dependent transhydrogenase.
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PMID:Assay and properties of 25-hydroxyvitamin D3 23-hydroxylase. Evidence that 23,25-dihydroxyvitamin D3 is a major metabolite in 1,25-dihydroxyvitamin D3-treated or fasted guinea pigs. 335 35

If given orally captan is relatively nontoxic, but it can be extremely toxic after parenteral exposure. Therefore, a single i.p. dose of captan (20 mg/kg) was given to male Sprague-Dawley rats and its effect on liver microsomal mixed function oxidases and certain serum enzymes (SDH, SGPT and SGOT) was studied. The single dose of captan caused marked depression of microsomal cytochrome P-450 and the activity of benzphetamine N-demethylase and aniline hydroxylase, and moderate elevation of the serum enzymes indicative of liver damage. However, reduced glutathione (100 mg/kg, i.p.) given prior to captan, appears to decrease the liver toxicity as measured by reduced inhibition of the microsomal enzymes and elevation of serum enzymes activity. The results suggest that glutathione and other compounds containing sulfhydryl groups may protect the subjects from captan-induced liver toxicity.
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PMID:Involvement of glutathione in the reduction of captan-induced in vivo inhibition of monooxygenases and liver toxicity in the rat. 338 36

Repeated administration of human chorionic gonadotropin to rats results in a maximal depression of testicular microsomal heme and cytochrome P-450 levels at 24 h, followed by increases that plateau at pretreatment levels by day six. Associated with the depressed levels of microsomal heme and cytochrome P-450 is an increase of testicular microsomal heme oxygenase activity at 12-24 h. Testicular mitochondrial delta-aminolevulinic acid synthase activity was increased at 24 h, and remained elevated throughout the 9-day treatment period. Pretreatment with 1,4,6-androstatrien-3,17-dione, an aromatase inhibitor, failed to prevent the depression of testicular microsomal heme or cytochrome P-450 or increased heme oxygenase activity caused by repeated administration of human chorionic gonadotropin, and administration of estradiol benzoate failed to alter testicular microsomal heme oxygenase activity suggesting that these parameters were not related to altered testicular estrogen content caused by increased aromatase activity. These results suggest that increased testicular heme oxygenase activity is associated with decreased microsomal heme and cytochrome P-450 content during human chorionic gonadotropin-induced desensitization.
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PMID:Increased rat testicular heme oxygenase activity associated with depressed microsomal heme and cytochrome P-450 levels after repeated administration of human chorionic gonadotropin. 348 41

Endotoxin-resistant C3H/HeJ mice were used to test the hypothesis that a macrophage product, possibly interleukin-1, might mediate the depression of liver cytochrome P-450-dependent drug metabolism in endotoxin-treated mice. Depression of liver drug metabolism by endotoxin was observed in normal mice (C3H/HeN) but not in C3H/HeJ mice. Serum transfer experiments demonstrated that a serum factor was responsible for the depression of liver drug metabolism. Experiments of passive transfer of peritoneal macrophages showed that this endotoxin-induced factor might be a macrophage product. In vitro experiments showed that endotoxin-stimulated monocytes produced a factor that depressed cytochrome P-450-dependent metabolism in cultured hepatocytes. Homogeneous human monocyte and recombinant interleukin-1 also depressed liver drug metabolism both in vivo and in vitro, suggesting that this macrophage product might be involved in the regulation of liver function by the immune system.
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PMID:Role of interleukin-1 in the depression of liver drug metabolism by endotoxin. 349 Oct 50


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