Effects of POCA on metabolism and function in the ischemic rat heart

Sodium 2-[5-(4-chlorophenyl)-pentyl]-oxirane-2-carboxylate (POCA) inhibits carnitine palmityltransferase I and fatty acid oxidation. The effects of POCA on cardiac function and on tissue levels of carnitine and coenzyme A esters were studied in the isolated rat heart subjected to 90 minutes of ischemia with and without 15 minutes of reperfusion. The perfusion medium contained 1.2 mM palmitate and 5.5 mM glucose plus or minus 0.5 mM POCA. This compound prevented accumulation of long-chain acylcarnitine and coenzyme A esters during ischemia and significantly improved the recovery of cardiac output after ischemia and reperfusion. Short-chain acylcarnitine levels were increased during ischemia by POCA. No effects were noted on tissue ATP and lactate levels. POCA may protect the ischemic heart by preventing accumulation of these toxic metabolites and by stimulating glucose utilization during ischemia.