A Note on the Pharmacology of Rescinnamine and Serpentine

Abstract

Abstract The pharmacological properties of rescinnamine and serpentine have been studied. Both lower the blood pressure of anaesthetised cats but rescinnamine has a prolonged effect whilst serpentine has only a brief action. Rescinnamine does not antagonise the effects of adrenaline or noradrenaline on the blood pressure of the cat or on the isolated heart, auricles or intestine. Serpentine antagonises vasoconstriction due to adrenaline and noradrenaline in the isolated perfused rat hindquarters but not that due to 5-hydroxytryptamine creatine sulphate, barium chloride or pitressin. Serpentine reversibly antagonises the pressor responses to bilateral carotid occlusion, central vagal stimulation and splanchnic stimulation. Rescinnamine irreversibly antagonises these responses and also the responses from compression of the abdominal aorta and hypoxia, which suggests both alkaloids have an action upon the sympathetic nervous system. Rescinnamine also has some direct depressant effects on cardiac, intestinal and skeletal muscle.