Effects of Captopril and Furyldihydropyriodine Ⅰ on Coronary Collateral Circulation in Dogs with Acute Myocardial Infarction

Aim To investigate the effects of intravenous infusion of captopril and furyldihydropyriodineⅠ（FDPⅠ） on coronary collateral circulation and infarct size in dogs for 120 minutes. Methods 18 anesthetized openchest dogs were subjected to left anterior descending coronary artery（LAD） occlusion. Retrograde blood flow（Qr） was measured through the ligated and cannulated LAD; collateral blood flow（Qc） was calculated from a load line equation. Captopril and FDPⅠ（200 μg/kg,respectively） and saline were intravenously infused to the dogs after 5minute coronary occlusion. Hemodynamics and collateral circulation indices were measured at different time. Myocardial infarct size was determined with TTC stain technique. Results Qr and Qc were increased markedly, collateral resistance and peripheral coronay resistance were decreased significantly after intravenous infusion of captopril and FDPⅠ, while no significant changes were observed for these indices in control group. Myocardial infarct size was reduced significantly in the two treated groups. Conclusion Captopril and FDPⅠ improved coronary collateral circulation in dogs with acute myocardial infarction and had a beneficial effect on ischemic myocardium.