[Quantitative analysis of the phospholipid composition of the myocardium in experimental diabetes mellitus: effect of total ischemia]

Abstract

Phospholipid composition was studied in the myocardium of rats and rabbits with alloxan diabetes developed after intravenous of intraperitoneal administration of alloxan and complicated by 60-min total ischemia. The diabetes developed within 4 weeks thereafter heart tissue was isolated and used for biochemical analyses. Total cardioplegic ischemia was simulated in the perfused heart after drastic interruption of perfusion. Composition of myocardial phospholipids was altered in alloxan diabetes: content of lysophosphoglycerides, lysophosphatidylcholine, lysophosphatidylethanolamine and of sphingomyelin was increased, while cardiolipin and phosphatidylethanolamine were decreased. In the diabetes-impaired heart tissue, a 2-fold increase was detected in the ratio of cholesterol/phospholipids, which corresponded to the viscosity of plasma membranes. Total ischemia within 60 min caused a further increase in the levels of lysophosphoglycerides in the diabetes-impaired tissue. Considerable differences in the content of phospholipids were maintained in control and diabetes-impaired heart tissues after ischemia and reperfusion; these differences were observed in the preischemic group. Thus, phospholipid composition was altered in the diabetes-impaired myocardia in presence and/or absence of ischemia.