Homocysteine levels of rats chronically treated with nicotine

Cigarette smoking has detrimental effects on the cardiovascular and cerebrovascular systems and among the contents of tobacco, nicotine shows considerable medical significance because of its toxicity. Homocysteine is an intermediate metabolite of methionine and increased levels of homocysteine may underlie atherosclerosis. In the present study, we investigated the relationship between the levels of homocysteine and nicotine in female and male rats which were treated with nicotine (0.35, 1.05 and 2.1 mg/kg, subcutaneously) for 20 days. Blood was obtained by cardiac puncture and serum cotinine levels, as an index of nicotine exposed, and homocysteine levels were measured by ;quot;Enzyme lmmunoassay (EIA);quot; and ;quot;Fluorescence Polarization lmmunoassay (FPIA);quot; respectively. Nicotine administration resulted in a dose dependent increase in the serum cotinine levels of the rats. Homocysteine levels were higher in female rats than male rats both in control and nicotine-administered groups, however nicotine treatment did not significantly change homocysteine levels in either sex. These results suggest that there is no direct correlation between plasma homocysteine levels and chronic nicotine exposure.Sigara içilmesi kardiyovasküler ve serebrovasküler sistemlerde zararlı etkilere neden olur ve toksisitesinden ötürü sigaradaki nikotin tıbben önemli bir bileşiktir. Homosistein, metioninin metabolizması sırasında oluşan bir ara üründür ve homosisteinin artışı aterosklerozun patogenezinde rol oynar. Bu çalışmada 20 gün boyunca nikotin (0.35, 1.05 ve 2.1 mg/kg, subkutan) uygulanan dişi ve erkek sıçanlarda nikotinin homosistein düzeylerine etkisi araştırılmıştır. Hayvanlardan intrakardiyak olarak kan alınmış ve serum homosistein düzeyleri immünolojik yöntem ("enzyme imunoassay", EIA) ile, maruz kalınan nikotin miktarının bir göstergesi olarak kotinin düzeyleri ise immünolojik floresans polarizasyon yöntemi ("fluorescence polarization immunoassay", FPIA) He ölçülmüştür. Sıçanlara nikotin uygulaması serum kotinin düzeylerinde doza bağımlı bir artışa neden olmuştur. Kontrol ve nikotin tedavi gruplarında dişi sıçanların homosistein düzeyleri erkek sıçanlardan yüksek bulunmuştur, ancak nikotin uygulaması her iki cinste de homosistein düzeylerinde anlamlı bir değişiklik yapmamıştır. Bu bulgular, kronik olarak nikotine maruz kalış He plazma homosistein düzeyleri arasında direkt bir ilişki olmadığını göstermektedir

The effects of vitamin E on catalase activies in various rat tissues

Vitamin E and other antioxidants prevent or minimize oxidative damage in biological systems. the level of antioxidant defense sufficient to protect the organism from high free radical concentrations is one of the new horizons for Vitamin E research. the role of Vitamin E as a protective agent aganist oxidative stress was evaluated by measuring the antioxidant enzyme catalase (CAT) activities in different tissues of Swiss male albino rats aged two months. in this study, rats were divided to three groups; control (n=10), E1 (n=5) which received 25 mg/kg. per day of Vitamin E, IM. for 10 days and E2 (n=7) which received 50 mg/kg. per day of Vitamin E, I.M. for 25 days. Catalase activities of cortex cerebrum,cerebellum, liver, kidney, heart and lung tissues were determined by a modified method of Luck and Aebi. Comparing the Vitamin E supplemented group (El +E2) with the controls, no significant difference could be detected in tissue CAT activities. However, in group E2 both renal and cardiac CAT activities were found to be higher when compared to the controls (p<0.01) as well as to the E1 group Since beneficial effects of Vitamin E has been observed on human health, this issue is very important for basic science and for the rapeutic approaches as well