共查询到5条相似文献,搜索用时 0 毫秒
1.
G. G. Thompson M. Small G. D. O. Lowe C. D. Forbes B. K. Park G. Scobie M. J. Brodie 《European journal of clinical pharmacology》1984,26(5):587-590
Summary Stanozolol is an anabolic steroid which is used in the treatment of aplastic anaemia and has been recently advocated for the prophylaxis of vascular thrombosis. Similar steroid substances stimulate the activity of -aminolaevulinic acid synthase (ALA S), the rate limiting enzyme of haem biosynthesis, in rat hepatocytes and chick embryo liver cell cultures and activate acute hepatic porphyria. In the present study stanozolol (10 mg daily for 14 days) has been shown to increase significantly leucocyte ALA S activity in 9 healthy male subjects. There was a concomitant rise in urinary ALA and total porphyrin excretion but no change in antipyrine kinetics or urinary 6 B hydroxycortisol excretion. In a complementary study in male Sprague Dawley rats, stanozolol administered intraperitoneally, produced a dose-dependent increase in hepatic ALA S activity without changing hepatic cytochrome P 450 content. Stanozolol has been clearly shown to elevate ALA S activity, probably directly, and, thereby, porphyrin production without affecting hepatic monooxygenase activity. This porphyrinogenic effect may be relevant to the successful treatment of aplastic anaemia with anabolic steroids. Leucocyte ALA S activity may provide a human system for the study of drug porphyrinogenicity in vivo. 相似文献
2.
Mercuric chloride (HgCl)2 is a toxic metal that causes oxidative damage in several tissues. N-acetylcysteine (NAC) is a sulfhydryl compound with antioxidant activity. In the present study, we investigated the in vitro effects of the association between HgCl2 and NAC in tissues of mice. For this purpose, we evaluated the in vitro effect of HgCl2 + NAC association on δ-aminolevulinate dehydratase (δ-ALA-D) activity and on thiobarbituric acid reactive substances (TBARS) levels in liver and kidney of mice. The results demonstrate that HgCl2 inhibited δ-ALA-D activity in both tissues. Hepatic δ-ALA-D activity inhibited by HgCl2 was potentiated by the highest concentration of NAC. The inhibition of hepatic δ-ALA-D activity seems to be related to sulfhydryl groups oxidation of the enzyme. We observed also that HgCl2 increased TBARS levels in kidney and liver. Hepatic TBARS levels were reduced by NAC, at higher concentration. In contrast, NAC, at higher concentration, increased renal TBARS levels. In conclusion, the inhibition of hepatic δ-aminolevulinate dehydratase activity induced by HgCl2 is potentiated by NAC in vitro, and this effect is not related to hepatic lipid peroxidation. 相似文献
3.
Martin Krøyer Rasmussen Galia Zamaratskaia Bente Andersen Bo Ekstrand 《Food and chemical toxicology》2012
Hepatic cytochrome P450 expression and activity are dependent on many factors, including dietary ingredients. In the present study, we investigated the in vivo and in vitro effect of chicory root on hepatic CYP3A and 2C in male pigs. Chicory feeding increased the expression of CYP3A29 mRNA but not CYP2C33. Correspondingly, CYP3A activity was increased by chicory feeding, while CYP2C activity was not affected. Additionally, the in vitro effect of chicory extract on the CYP3A activity was investigated. It was shown that CYP3A activity in the microsomes from male pigs was inhibited, but this effect was eliminated by pre-incubation. In both male and female pigs the CYP3A activity was increased in the presence of chicory after pre-incubation. Furthermore, gender-related differences in mRNA expression and activity were observed. CYP3A mRNA expression was greater in female pigs; this was not reflected on activity. For CYP2C, no difference in mRNA expression was observed, while CYP2C activity was greater in female pigs. Surprisingly, the expression of the constitutive androstane receptor, pregnane X receptor and aryl hydrocarbon receptor did not differ with feed or gender. In conclusion, chicory root modifies the expression and activity of CYP3A in vivo and in vitro, while CYP2C is not affected. 相似文献
4.
Ítala Mônica de Sales Santos Chistiane Mendes Feitosa Dejiang Feng Joaquín Jordán 《Pharmacology, biochemistry, and behavior》2010,95(1):88-91
In the present study we investigated the effects of lipoic acid (LA) on δ-aminolevulinic dehydratase (δ-ALA-D) and Na+, K+-ATPase activities in rat brain after seizures induction by pilocarpine. Wistar rats were treated with 0.9% saline (i.p., control group), lipoic acid (10 mg/kg, i.p., LA group), pilocarpine (400 mg/kg, i.p., pilocarpine group), or the combination of LA (10 mg/kg, i.p.) with pilocarpine (400 mg/kg, i.p.), 30 min before administration of LA (LA plus pilocarpine group). After the treatments all groups were observed for 1 h. The enzyme activities (δ-ALA-D and Na+, K+-ATPase) were measured using spectrophotometric methods, and the results were compared with that obtained from saline and pilocarpine-treated animals. Neuroprotective effects of LA against seizures were evaluated based on those enzyme activities. The pilocarpine group showed a reduction in δ-ALA-D and Na+, K+-ATPase activities after seizures. In turn, LA plus pilocarpine abolished the appearance of seizures and reversed the decreased in δ-ALA-D and Na+, K+-ATPase activities produced by seizures, when compared to the pilocarpine seizing group. The results from the present study demonstrate that preadministration of LA abolished seizure episodes induced by pilocarpine in rat, probably by increasing δ-ALA-D and Na+, K+-ATPase activities in rat brain during seizures. 相似文献
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