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)

Administration of N-nitrosodiethylamine (diethylnitrosamine, DEN) to mice caused a loss of cytochrome P-450 and a corresponding depression in the activities of aminopyrine demethylase and aniline hydroxylase. Maximum effects were achieved 24 hr. after a single dose of 100 mg/kg. In chronic experiments, similar effects were achieved after animals had been drinking water containing 50 ppm of DEN for 12 weeks. The effects of DEN on aminopyrine demethylase could not be reproduced by collecting microsomes, from homogenates which had been treated with DEN in vitro. Homogenates prepared from livers of mice treated chronically with DEN were used to activate compounds to mutagens in the Salmonella/microsome test of Ames. Activation by these homogenates was not lower than activation by homogenates prepared from control animals. In fact, activation of aflatoxin B1 was enhanced by use of homogenates from DEN-treated animals as source of activating enzymes.
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PMID:Effects of N-nitrosodiethylamine on murine hepatic mixed-function-oxidase activities. 36 84

1 Pretreatment of rats with intraperitoneal injections of lead was shown to result in a depression of the microsomal mixed function oxidase system, as assessed by a decrease in hepatic microsomal P-450 and b5 content and by a decrease in the activity of the enzymes aniline hydroxylase and aminopyrine demethylase. Lead had a more marked effect on cytochrome P-450 than b5. 2 The activity of the rate-limiting enzyme of haem biosynthesis, delta-aminolaevulinic acid synthase, was inversely correlated with the microsomal cytochrome P-450 content. 3 The activity of the haem biosynthetic enzymes delta-aminolaevulinic acid dehydratase, coproporphyrinogen oxidase and ferrochelatase were decreased by increasing lead pretreatment. 4 The activity of the haem catabolic enzyme, haem oxygenase, was increased by lead pretreatment.
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PMID:Hepatic drug metabolism and haem biosynthesis in lead-poisoned rats. 65 97

In these studies the effects of ingested arsenic (As(+5)) on hepatic heme biosynthetic capability and hemoprotein function in adult male rats were investigated. Animals exposed for 6 weeks to 0, 20, 40, or 85 ppm sodium arsenate in the drinking water suffered depression of hepatic delta-aminolevulinic acid (ALA) synthetase and heme synthetase (ferrochelatase) activities, with maximal decreases to 67 and 55% of control levels, respectively, at 85 ppm. Concomitantly, urinary uroporphyrin levels were elevated by as much as 12 times, and coproporphyrin by as much as 9 times, control values. The rate of incorporation of (3)H-ALA into mitochondrial and microsomal hemes was depressed by 40-50% at 20 ppm but was increased with regard to controls by as much as 150% at the higher treatment levels. A similar biphasic pattern was observed in regard to (14)C-leucine incorporation into cellular membranal proteins. In contrast, the levels of ALA dehydratase, uroporphyrinogen I synthetase, aminopyrine demethylase, and cytochrome P-450 were not significantly changed in As(+5)-treated rats. These results support the hypothesis that chronic, low level, arsenic exposure results in selective inhibition of mitochondrial-bound heme biosynthetic pathway enzymes (ALA synthetase and heme synthetase) resulting in a substantial increase in urinary porphyrins, uniquely characterized by a greater increase in uroporphyrin than coproporphyrin levels. These changes occur independent of, or prior to, alterations in hepatic hemoprotein-dependent functions and may thus serve in the clinical analysis of pretoxic exposure to arsenic compounds in human populations.
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PMID:Effects of chronic arsenic exposure on hematopoietic function in adult mammalian liver. 90

Dietary protein deficiency is known to modify the response to the pharmacotoxicological activities of drugs and foreign compounds, due in part to altered rates of metabolism. Prediction of whether in vivo susceptibilities to foreign compounds are increased or decreased in protein deficient animals has been said to be related to the relative toxicites of the metabolic products. We have shown that weanling rats fed semipurified casein diets for 15 days show a 75% depression of hepatic microsomal mixed function oxidase activities. About one-fourth of this decrease is due to a retardation of the normal rate of liver cell proliferation and less microsomal protein; the remaining three-fourths is due to a reduction of the specific enzyme activity. This latter decrease is closely correlated with similar decreases in cytochrome P-450 and cytochrome c reductase activities and cytochrome P-450 contents. Although protein deficiency affects the relative contents of phosphatidylcholine and cytochrome P-450, this does not result in modifications of the Km for metabolism, as is seen with phenobarbital administration in the various dietary groups. The depression of mixed function oxidase enzyme activities caused by feeding the protein deficient diet for 15 days can be restored to normal by feeding the 20% casein diets for an additional 30 days in the case of aniline hydroxylase but only partially in the case of ethylmorphine N-demethylase. The complexities of determining the role of metabolism as a modulator of protein deficiency effects on foreign compound toxicity are discussed.
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PMID:The effect of quantity and quality of dietary protein on drug metabolism. 97 91

Studies were conducted to examine the effect of a single and repeated administrations of garlic oil (diallyl sulfide) on Phase I and Phase II biotransformation enzymes in rats. Adult, male Sprague-Dawley rats treated with a single dose of garlic oil (500 mg/kg i.p.) showed a significant depression of hepatic cytochrome P-450, aminopyrine N-demethylase and aniline hydroxylase while microsomal protein content, cytochrome b5, NADPH-cytochrome c reductase, benzphetamine N-demethylase and cytosolic glutathione, S-transferase remained unaffected 24 h following the treatment. Although certain microsomal enzymes were depressed, there was no liver damage caused by garlic oil as judged by the putative serum enzyme test. On the other hand, daily administration of garlic oil (50 mg/kg i.p. for 5 days) produced a significant increase in hepatic cytochrome P-450, aminopyrine N-demethylase and benzphetamine N-demethylase activities, but not in the rest of the aforementioned parameters of biotransformation reactions. These data indicate that the effect of garlic oil on the hepatic drug-metabolizing enzyme system is dose-dependent.
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PMID:Alterations in hepatic phase I and phase II biotransformation enzymes by garlic oil in rats. 159 88

The effect of a single dose of bacterial endotoxin (lipopolysaccharide, LPS) was compared with that of tumor implantation in mice on the activity of several hepatic cytochrome P-450-dependent monooxygenases. These included ethoxycoumarin O-deethylase, p-nitrophenol hydroxylase, aminopyrine N-demethylase, pentoxyresorufin O-depentylase, ethoxyresorufin O-deethylase and testosterone hydroxylase. For this purpose, mice were treated i.p. with 5 micrograms of LPS or implanted in the right paw with S 180 sarcoma. A comparable depression (30-50%) of total microsomal P-450 content as well as of the different P-450 monooxygenase activities tested was observed in LPS-treated mice (24 h after LPS) and in tumor bearing mice (12 days after implantation). The lack of differences in the pattern of depression of microsomal enzymes between LPS-treated and tumor-bearing mice suggests that a common mechanisms might be involved in the depression of P-450 by LPS or S-180 implantation.
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PMID:Depression of hepatic drug metabolism in endotoxin-treated and sarcoma-bearing mice. 160 46

The antimetastatic effect of cepharanthin with or without 5-fluorouracil (5-FU) was examined in an experimental model of lung metastasis induced by Lewis lung carcinoma (3LL) in C57BL/6crSlc mice. Injection of cepharanthin i.p. after removal of the implanted primary tumor inhibited the development of lung metastases. Combination therapy with cepharanthin plus 5-FU inhibited significantly the lung metastases. Lung metastases were inhibited by i.v. injection of peritoneal macrophages activated with cepharanthin. Cepharanthin depressed aniline hydroxylase and aminopyrine demethylase activities of the hepatic microsomal drug-metabolizing system in tumor-bearing mice. Moreover, the concentration of 5-FU in the tissues (lung, liver, kidney, spleen and blood) was increased significantly by coadministration of cepharanthin. A possible mechanism of the inhibition of lung metastases by treatment with cepharanthin may be that this drug acts through macrophage activation and depression of the hepatic microsomal drug-metabolizing system. These findings raise the possibility that combination therapy with cepharanthin plus 5-FU may have clinical value in the prevention of cancer metastasis.
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PMID:Inhibitory effect of a biscoclaurine alkaloid, cepharanthin, on lung metastasis of Lewis lung carcinoma. 188 Sep 98

Ionol, a synthetic antioxidant, limits the stressor liver injury to a greater extent than sodium, valproate and phenazepam, activators of a GABA-ergic link of the stress-limiting organism systems. This injury is exhibited in the organospecific elevated levels of blood enzymes fructosediphosphate aldolase depression of N-demethylase activity of microsomal monooxygenases and a decrease in the amount of cytochromes P-450 and B5.
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PMID:[Comparative evaluation of the protective effect of sodium valproate, phenazepam and ionol in stress-induced liver damage in rats]. 189 54

The whole X-irradiation (7 Gy) of male rat, mouse and guinea-pig caused in general similar alterations in the content of cytochrome P-450 and aminopyrine-N-demethylase activity in liver microsomes. On the 5-7th day after irradiation the parameters were 39-79% of the normal level. The same postradiation changes were observed in females of these animal species but in females of rats and guinea-pigs the effect was less expressed. The depression of activity in liver microsomal cytochrome P-450-dependent monooxygenase system has been concluded to be one of the characteristic features of acute form in radiation damage.
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PMID:[The effect of x-ray irradiation on the cytochrome P-450-dependent mono-oxygenase system of the liver in different animal species]. 207 33

The influence of Monensin, Tiamulin and the simultaneous administration of the two substances on the microsomal, mixed function oxidases was studied on cockerels. Monensin was seen to cause a slight depression in the amount of cytochrome P-450 and cytochrome b5 as well as in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and p-nitroanisole-O-demethylase. Tiamulin induced a moderate increase in the amount of cytochrome P-450 and in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and aminopyrine-N-demethylase. The combined administration of monensin and tiamulin resulted in marked induction of the microsomal enzymes; the amount of cytochrome P-450 reduced by metyrapone or carbon monoxide increased 2.5 or 2-times, respectively, and the activities of the tested microsomal hydroxylases and demethylases showed also an expressed increase. At the same time the formation of lipid peroxides also markedly increased and the GSH concentration was reduced. In conclusion, the results of the investigations indicate that the simultaneous application of monensin and tiamulin cause a marked induction of the drug-metabolizing microsomal enzymes and a significant increase in the lipid peroxide formation.
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PMID:[The effect of monensin, tiamulin and the simultaneous administration of both substances on the microsomal mixed function oxidases and on the peroxide formation in broilers]. 224 30


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