Protease inhibitor leupeptin attenuates myocardial stunning in rat heart.
BACKGROUND
In order to test the hypothesis that cardiac protein degradation contributes to the pathogenesis of myocardial stunning, the effect of protease inhibitor leupeptin on the postischemic hemodynamics and metabolic functioning was measured in isolated rat hearts.


METHODS
Isolated rat hearts were perfused in Langendorff mode in the presence or absence of leupeptin (10 Kg/ml for 10 min.), and then subjected to 20 min. of normothermic ischemia and 30 min. of reperfusion. Aortic pressure, cardiac output, coronary flow (CF), global oxygen consumption (MVO2), carbon dioxide and [H+] release, and [Ca2+] uptake were investigated.


RESULTS
Hearts pretreated with leupeptin exhibited better postischemic return of systolic, diastolic and developed aortic pressure and faster return of CF to preischemic values during reperfusion. MVO2 and CO2 release were lower in this group in the 10th and 15th min. of reperfusion and [Ca2+] uptake higher in the 5th and 15th min. of reperfusion


CONCLUSIONS
Leupeptin protects the heart from myocardial stunning, which is consistent with the idea that proteases contribute to the pathogenesis of this phenomenon.
Rudziński
Tomasz
T
Department of Cardiosurgery, Institute of Cardiology, Medical University of Łodź, Poland.
Mussur
Michał
M
Gwiazda
Zbigniew
Z
Mussur
Mirosław
M
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002302:Cardiac Output / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003546:Cysteine Endopeptidases / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D066298:In Vitro Techniques; D007976:Leupeptins / Q000494:pharmacology*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D017682:Myocardial Stunning / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D010101:Oxygen Consumption / Q000187:drug effects; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar
D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D002245:Carbon Dioxide; D003546:Cysteine Endopeptidases; C032854:leupeptin; D002118:Calcium