Cardiotonic pills (CP) is a compound Chinese medicine widely used in China, as well as other countries, for the treatment of cardiovascular disease. However, limited data are available regarding the mechanism of action of CP on myocardial function during ischemia-reperfusion (I/R) injury. In this study, we examined the effect of CP on I/R-induced coronary microcirculatory disturbance and myocardial damage. Male Sprague-Dawley rats were subjected to left coronary anterior descending branch occlusion for 30 min followed by reperfusion with or without pretreatment with CP (0.1, 0.4, or 0.8 g/kg). Coronary blood flow, vascular diameter, velocity of red blood cells, and albumin leakage were evaluated in vivo after reperfusion. Neutrophil expression of CD18, malondialdehyde, inhibitor-kappaBalpha, myocardial infarction, endothelial expression of intercellular adhesion molecule 1, apoptosis-related proteins, and histological and ultrastructural evidence of myocardial damage were assessed after reperfusion. Pretreatment with CP (0.8 g/kg) significantly attenuated the I/R-induced myocardial microcirculatory disturbance, including decreased coronary blood flow and red blood cell velocity in arterioles, increased expression of CD18 on neutrophils and intercellular adhesion molecule 1 on endothelial cells, and albumin leakage from venules. In addition, the drug significantly ameliorated the I/R-induced myocardial damage and apoptosis indicated by increased malondialdehyde, infarct size, myocardial ultrastructural changes, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive myocardial cells, inhibitor-kappaBalpha degradation, and expression of Bcl-2, Bax, and caspase-3 in myocardial tissues. The results provide evidence for the potential role of CP in preventing microcirculatory disturbance and myocardial damage following I/R injury.
