Tag Archives: ethanol
Different sensitivity of Na(+),K(+)-ATPase and Mg(2+)-АТРase to ethanol and arachidonic acid in rat colon smooth muscle under pretreatment of cellular membranes with Ds-Na
A. A. Kaplia
Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: kaplya@biochem.kiev.ua
The methodological procedure provides the detection of the relatively high Na+,K+-ATPase functional activity in the crude cellular membranes of rat colon smooth muscle (CSM) following standard detergent pretreatment (with Ds-Na vs digitonin). It includes the essential discrete steps: detergent membrane permeabilization under optimal detergent/protein ratio and active site protection by ATP (for Ds-Na) prior enzymatic reaction with substantial detergent dilution far below critical micelle concentration in the ATPase medium. The high level of the Na+,K+-ATPase activity, originally detected in CSM, did not differ for two detergents and was comparable with ouabain-resistant Mg2+,АТР-hydrolase activity, The features of ATPase protein-lipid complexes were evaluated by the enzyme sensitivity to the effect of ethanol and arachidonic acid with different membrane disordering effectiveness. The long-chain fatty acid is a more effective inhibitor as compared with aliphatic alcohol for both ATPases. Mg2+,АТР-hydrolase appeared to be much more resistant to inactivation than Na+,K+-ATPase. The data reflect the possible differences in lipid dependence of two enzymatic systems due to the peculiarities of the structural arrangement in membrane and importance of the hydrophobic microenvironment for mechanism of catalysis. Thus, the data represent the approach to the simple and reliable Na+,K+-АТРase activity determination in nonpurified CSM membranes, acceptable for different tissues and appropriate for quantitative comparison in pathophysiological studies and for testing the impact of diverse effectors on Na+,K+-АТРase.
Alterations of prooxidant-antioxidant system of rat liver at ethanol and tetracycline action
Kh. Yu. Nedoshytko
I. Ya. Horbachevsky Ternopil State Medical University, Ukraine;
e-mail: khrystynan@ukr.net
The state of antioxidant system and fatty acid composition of lipids in the liver tissues of rats of different sex at the ethanol and tetracycline action and at the influence of biologically active additives (BAA) “Alpha + Omega” at a dose of 0.5 mg/kg b.w. per os was investigated. It was found that the contet of lipid peroxidation products in the liver was increased at the action of 40 % ethanol at a dose of 7 ml/kg b.w. per os and tetracycline – 500 mg/kg and more profound at their joint using. However, the content of diene conjugates was stronger increased in the liver of females at the action of ethanol, while in the liver of males at the action of tetracycline (Р < 0.05). It was shown that the application of the investigated compounds led to the reduction of an antioxidant defense system activity of males and females liver, as evidenced by the decrease of superoxide dismutase activity by 46 and 43% and reduction of glutathione content by 39 and 38% (Р < 0.05). The activity of alanineaminotransferase, aspartateaminotransferase and alkalinephosphatase was increased in the liver of males and females under the influence of ethanol and tetracycline and more profound at their joint usage (Р < 0.05). It was established that ethanol and tetracycline unidirectionally changed fatty acid composition of total lipids of rat liver, but at the ethanol action the changes were more expressed in females while at the tetracycline action in males. The application during 14 days of BAA “Alpha + Omega” to male and female rats with an acute tetracycline damage at subacute ethanol action led to partial normalization of prooxidant-antioxidant system and the relative content of total lipids fatty acids of the liver of both sexes animals.