Control of energy production in myocardial ischemia

Long chain fatty acyl-CoA esters are potent in vitro and in vivo inhibitors of adenine nucleotide translocation in heart mitochondria. Within a short time following production of myocardial ischemia, the dog heart exhibits an increased concentration of long chain acyl-CoA esters associated with a decrease in adenine nucleotide translocase activity. In contrast to liver, the tricarboxylate carrier system for citrate and phosphoenolpyruvate is rather low in heart mitochondria. Phosphoenolpyruvate-stimulated calcium egress from heart mitochondria may, therefore, result from transport of this anion on the adenine nucleotide translocase. During myocardial ischemia effective modulation of these metabolite trasnport systems are disrupted by accumulation of long chain acyl-CoA esters which leads to a decrease in the overall energy charge of the cell.