Mechanisms involved in coronary artery dilatation during respiratory acidosis in the isolated perfused rat heart

A rat Langendorff heart preparation, perfused at constant pressure, was use d to evaluate the role of K-ATP channels in respiratory acidosis-induced co ronary hyperemia. Prior administration of glibenclamide, an inhibitor of K- ATP channels, reduced basal flow rates and eliminated the hyperemia associa ted with hypercapnia. These results implicate K-ATP channels as a functiona l link in the respiratory acidosis-induced increase in coronary flow.