Effect of Antihistaminic and Antiserotonin Drugs on Vascular Responses to E. coli Endotoxin in the Cat.

Abstract

Dibenamine (15 mg/kg), pyrilamine (5 mg/kg), and lysergic acid diethylamide (LSD) (.5 mg/kg) were given singly or in combination to anesthetized cats prior to the intravenous administration of a small dose of endotoxin (.05 mg/kg). Dibenamine, dibenamine plus pyrilamine, and LSD with or without pyrilamine significantly moderated the characteristic early fall of arterial blood pressure. The characteristic early rise of pulmonary arterial pressure was not significantly lessened. These findings are compatible with the possibility that histamine and serotonin are active in the early phases of the endotoxin response in cats.