Xanthonolol: A calcium channel and beta-adrenoceptor blocker with vasodilating properties

Abstract

1. 1. Xanthonolol (0.1–0.5 mg/kg, i.v.) reduced the blood pressure, heart rate, and l-isoproterenol (0.05 μg/kg, i.v.)-induced tachycardia in rats. 2. 2. In the isolated guinea-pig right atrium, xanthonolol (10 −6−3 × 10 −4 M) produced long-lasting negative, inhibited l-isoproterenol-induced positive chronotropic effects, prevented the rate-increasing effects of increased extracellular Ca 2+ (3.0–9.0 mM), and inhibited Ca 2+ (3.0–9.0 mM)-induced heart rate-increase. 3. 3. In the isolated guinea-pig thoracic aorta, the contractions induced by CaCl 2 (0.1–5.0 mM) were inhibited by xanthonolol (10 −6–10 −4 M). 4. 4. Xanthonolol is suggested to have a calcium channel and beta adrenergic blocking effect with vasodilating properties.