Adaptive Changes Induced by Chronic Ethanol Ingestion on Hepatic Mitochondrial and Microsomal Enzyme Activities
نویسنده
چکیده
Ethanol exerts its pbarmacologlcal effects by alteriag the pkysico-ckemical propeof biological membranes. Modlflcatlons induced by ethanol may reta& in ckangeg lo the activity of membtane-boand enzymes tkat have been shown to reqdre a speclflc membram? flnldlty and composition for optimal function. In tbll study we have carried oat the analysis of the effects of ethanol on the different enzyme activities of bepatlc mlcrosomes and mlt-a. Oar results sbow that cbronlc ethanol treatment causes marked changes to enzyme actlvity ln tf#e mltockondrial aad microsomal electron-tramport systems ln cklck liver. Tke observedinthe mitochondrial enzyme activltles studled, indicates that ethanol lngestlon 8epreclses the fun&onallty of tbe respiratory-chain. In microsomes, NADH cytocbtome c redactase actlvlty was signlhntly decreased wbilst NADH cytocbtome b, red&ase actlvlty was hreased aider etkanol administration. Hepatic mitochondria and microsomes from control aml chronic etbanoltreated chicks were submitted to ethanol ia uitro in order to stody the po@slble existeoce of adaptive changes in the dllferent enzyme systems as conseqoence of long-term ethanol admlnistration. Incubation of control membranes wltb dilfemnt amounts of ethanol ihced marked alterations in enzyme activities. In membranes isolated from etlmnol-treated &l&s, ethanol also ptodaced a shilar effect except wltk cytocluome oxldase and NADH cytochme b, redo&se, which resisted alteration by ethanol added, soggesting the existence of adaptlve dmnges ln he-se enzyme activltles that allow tbem to remain mmltered after exposure to ethanol in oh.
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