{"title":"Regulation of pyruvate dehydrogenase complex activity during myocardial ischemia.","authors":"T C Vary, P J Randle","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>The effect of ischemia on the concentration of active pyruvate dehydrogenase (PDH) complex has been investigated in glucose-perfused hearts of normal rats fed a normal diet or a high-fat diet or starved for 48 hr and in hearts from alloxan-diabetic rats. Global ischemia induced by low flow (approximately equal to 1 ml/min) lowered the concentration of active complex under most conditions employed. Parallel studies of the effect of anoxia and of potassium arrest of the heart indicated that the effect of low-flow ischemia may result from decreased mechanical activity of the heart as a consequence of tissue hypoxia; the enzymatic mechanism may be activation of PDH kinase by increased reduction of mitochondrial NAD. In hearts of normal rats fed a normal diet, global ischemia induced by zero flow increased the concentration of active complex. Evidence is given that this may result from a combination of anoxia and acidosis. In aerobic perfusions, concentrations of active complex were ranked in the order: normal diet greater than high-fat diet greater than 48-hr starved greater than alloxan-diabetic. This order was maintained when the concentration of active complex was lowered by global ischemia induced by zero flow.</p>","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in myocardiology","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The effect of ischemia on the concentration of active pyruvate dehydrogenase (PDH) complex has been investigated in glucose-perfused hearts of normal rats fed a normal diet or a high-fat diet or starved for 48 hr and in hearts from alloxan-diabetic rats. Global ischemia induced by low flow (approximately equal to 1 ml/min) lowered the concentration of active complex under most conditions employed. Parallel studies of the effect of anoxia and of potassium arrest of the heart indicated that the effect of low-flow ischemia may result from decreased mechanical activity of the heart as a consequence of tissue hypoxia; the enzymatic mechanism may be activation of PDH kinase by increased reduction of mitochondrial NAD. In hearts of normal rats fed a normal diet, global ischemia induced by zero flow increased the concentration of active complex. Evidence is given that this may result from a combination of anoxia and acidosis. In aerobic perfusions, concentrations of active complex were ranked in the order: normal diet greater than high-fat diet greater than 48-hr starved greater than alloxan-diabetic. This order was maintained when the concentration of active complex was lowered by global ischemia induced by zero flow.