Characterisation of the canine cardiac sarcolemma in experimental myocardial ischemia.

The cardiac sarcolemma was characterized in 13 normal and 11 ischemic dog hearts by enzyme analysis and compositional assays. Significant decreases in the activities of the sodium-potassium and calcium pumps and structural compositional disturbances were observed in ischemia. High concentrations of oleic acid, a fatty acid and palmitoyl carnitine, a fatty acid intermediate caused inhibition of the enzyme pump activities of the normal sarcolemma. Thus, ischemia results in the functional impairment of the sarcolemma. Accumulation of fatty acid and fatty acid intermediates, occurring in myocardial ischemia, could be an underlying mechanism.