Cardiovascular effects in the rat of ketanserin, a novel 5-hydroxytryptamine receptor blocking agent

Abstract

Following intravenous administration of ketanserin (0.3–10 mg kg⁻¹) to conscious or anaesthetized normotensive and spontaneously hypertensive rats there were dose‐dependent blood pressure reductions but no compensatory tachycardia. Intracerebroventricular administration of ketanserin (25–500 μg) had inconsistent and largely insignificant cardiovascular effects. In a dose range where it produces hypotension ketanserin antagonized the pressor responses to adrenaline and noradrenaline as well as to 5‐hydroxytryptamine in monoamine depleted and spinalized rats. It is suggested that the hypotensive action of ketanserin in the rat does not involve a central mechanism but a peripheral α‐adrenolytic action is implicated.