PHARMACOLOGICAL CHARACTERISTICS OF SHO-SEIRYU-TO, AN ANTIALLERGIC KAMPO MEDICINE WITHOUT EFFECTS ON HISTAMINE H-1 RECEPTORS AND MUSCARINIC CHOLINERGIC SYSTEM IN THE BRAIN

The pharmacological characteristics of Sho-seiryu-to, an antiallergic Kampo medicine, were investigated. Forty-eight-hour passive cutaneous anaphylactic (PCA) reaction was significantly inhibited in rats orally administered Sho-seiryu-to (1000 mg/kg). Sho-seiryu-to significantly inhibited increase in vascular permeability induced by histamine. Thes e data confirm previous findings that Sko-seiryu-to has antiallergic a ctivity in animals and suggest that the antagonism of histamine may be an antiallergic mechanism of Sho-seiryu-to. Sho-seiryu-to did not aff ect locomotor activity or motor coordination in mice. Although ketotif en prolonged sleeping rime induced by pentobarbital, Sho-seiryu-to had no such effect. Nor was there any effect on oxotremorine-induced trem or and [H-3]-mepyramine binding to histamine H-1 receptors in rat brai n. Thus, Sho-seiryu-to appears to be useful for treating type I allerg y, with relatively few side effects such as sedation and drowsiness du e mainly to blockade of histamine H-1 and muscarinic receptors in the brain.