In vivo 31P-NMR spectroscopy at epicardium under hypoxia.

Pharmacological protection of acute ischemic myocardial injury was studied using diltiazem, bunazosin, coenzyme-Q10 (Co-Q), and nicorandil, in dogs of which the left anterior descending coronary artery was ligated for 60 min. Drugs were given intravenously prior to and/or during coronary ligation. Co-Q, bunazosin and diltiazem suppressed degradation of sarcoplasmic reticulum (SR) expressed as inhibitions of reduction in Ca++-dependent ATPase activity and degradation of major ATPase protein. Fine structures of ischemic myocardial cells were simultaneously retained as well. On the contrary, the effects of nicorandil on ischemic myocardial injury were few. It is likely that protection of ischemic myocardial injury could be expected with drugs which react with ischemic myocardium directly and inhibit excess inflow of extracellular Ca++ in ischemic myocardium.