Enhancement of antithrombotic effect of aspirin by metoclopramide in rats.

The potential antithrombotic effect of aspirin and metoclopramide were studied in a model of arterial thrombosis in rats. Thrombosis was produced in the abdominal aorta by the combination of local partial obstruction and intravenous administration of hypotonic saline containing 5-HT. The resulting aortic occlusion and the effects of drugs were quantified by measuring rectal temperature. Metoclopramide as well as ketanserine effectively reversed while zacopride failed to alter thrombotic effect. Metoclopramide or ketanserine when combined with aspirin enhanced the antithrombotic effect of the latter. On the other hand, co-administration of metoclopramide with ketanserine failed to show any synergistic effect. As with ketanserine, the antithrombotic effect of metoclopramide appeared to be mediated through the blockade of 5-HT2 receptors in the platelets.