BEPRIDIL - HEMODYNAMIC AND CORONARY EFFECTS ON NORMAL AND-OR ISCHEMIC MYOCARDIUM IN DOGS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 11  (4) , 391-409
Abstract
The effects of bepridil, an apparent Ca antagonist, were studied on arterial blood pressure and heart rate in unanesthetized dogs; on coronary and systemic hemodynamics in anesthetized dogs; and on regional blood flow (RBF) in the myocardium of anesthetized dogs either normal or experimentally ischemic from temporary and/or permanent coronary occlusion. Bepridil in unanesthetized dogs does not cause any significant change in heart rate or systolic blood pressure. The mean and diastolic blood pressures increase at the end of the observation period 20 min after the 2nd injection. Bepridil in anesthetized dogs induces a fall in peripheral resistance, with a drop in arterial blood pressure without any alteration in cardiac output. Heart rate and contractile force are decreased while coronary flow is increased. In models of localized transitory myocardial ischemia, bepridil (1 mg/kg i.v.) induces a general increase in absolute RBF, particularly causing a favorable redistribution of coronary blood to the endocardium in ischemic areas, as evidenced by the improved endocardium/epicardium irrigation ratio. These favorable effects disappear when the dose of bepridil (3 mg/kg) used in a preparation induces a marked drop in in blood pressure and a fall in coronary perfusion. In models of localized permanent myocardial ischemia, bepridil has no effects on RBF in healthy or ischemic areas, or on the endocardium/epicardium irrigation ratios in these 2 types of areas.