Effect of NCO-700, an inhibitor of protease, on myocardial pH decreased by coronary occlusion in dogs.
During myocardial ischemia in dogs effects of NCO-700, a protease inhibitor on myocardial pH, were investigated. Ischemia was produced for 90 min by partial occlusion of the left anterior descending coronary artery (LAD). Myocardial pH was measured by a micro glass pH electrode inserted in the subendocardium of the LAD area. Before partial occlusion, myocardial pH was 7.50-7.67. It decreased by 0.65 to 0.86 pH units after partial occlusion. NCO-700 was injected intravenously after 30 min partial occlusion. At a dose of 5 or 20 mg/kg NCO-700 increased myocardial pH, which had been decreased by LAD partial occlusion, by 0.26 or 0.31 pH units, respectively. In the nonischemic myocardium pH increased only 0.03 units. Drug-induced restoration of myocardial [H+] was then calculated. At a dose of 5 or 20 mg/kg NCO-700 restored myocardial [H+], which had been increased by partial occlusion. However, NCO-700 did not attenuate the ischemia-induced elevation of ST segment of the surface electrocardiogram. These observations demonstrate that NCO-700 attenuates myocardial pH depressed by partial occlusion of LAD.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000378:metabolism*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology*
D010879:Piperazines; D011480:Protease Inhibitors; C036798:NCO 700