RESINFERATOXIN, AN ULTRAPOTENT CAPSAICIN ANALOG, HAS ANTIEMETIC PROPERTIES IN THE FERRET

Resinferatoxin (100 mug/kg, s.c.), the ultrapotent analogue of capsaic in, when given acutely blocked radiation-(200 rads) and copper sulphat e (40 mg% 30 ml, p.o.)-induced emesis in ferrets and substantially dec reased loperamide (0.5 mg/kg, s.c.)-induced vomiting, without signific antly affecting the von Bezold-Jarisch reflex or gag reflex. It also p roduced a decrease in core temperature as has been reported for capsai cin. The observation that resinferatoxin reduced or blocked emesis ind uced by both centrally (loperamide) and peripherally (CuSO4, radiation ) acting stimuli suggests a novel anti-emetic action that may provide an insight into clinically useful innovative anti-emetics. The mechani sm by which resinferatoxin has its anti-emetic effect is at present un known, although the combination of results from the present study sugg est a central site of action involving modulation of release of neurot ransmitter, possibly in the nucleus tractus solitarius.