Mechanism of hypotensive action of scoparone

Journal/Book: Indian Journal of Medical Researche. 1988; 87: 387-394.

Abstract: Scoparone (6, 7-dimelhylesculetin) produced a prolonged dose-related fall of blood pressure in anaesthetized normotensive dogs. Prior atropinization, antihistaminic treatment, betaadrenoceptor blockade and bilateral vagotomy and/or carotid sinus denervation did not influence the depressor response of scoparone, whereas alpha-adrenoceptor blockade, ganglionic blockade, reserpinization and spinal cord resection slightly reduced the response. The cardiovascular responses to vasoconstrictor Agnes and dimethyl phenyl piperazinium iodide were enhanced and responses to acetylcholine, histamine, peripheral vagal stimulation and carotid artery occlusion were reduced. The drug caused no orthostatic hypotension. Cross head circulation preparations demonstrated both the central and the peripheral sites of action. Scoparone lowered the arterial blood pressure (30±3 mmHg) and elevated venous pressure (20±3.5 mmHg) in the hind limb of dog and increased the perfusion outflow in vessels perfused with depolarizing solution in rat's hindquarter. The results suggest that the hypotensive action of scoparone is due to direct vasomotor inhibition at the central site and also to marked peripheral vasodilation of the arterial blood vessels.

Zurück | Weiter