Hyperthermic effects of D-lysergic acid diethylamide (LSD) and its derivatives in rabbits and rats

Several D-lysergic acid diethylamide (LSD) derivatives including metabolites of LSD in animals liver and Streptomyces such as D-lysergic acid ethyl, 2-hydroxyethylamide (LEO), D-lysergic acid ethylamide (LAE), D-norlysergic acid diethylamide (norLSD) and synthetic N6-allyl-D-norlysergic acid diethylamide (allyl-nor LSD) were studied with rabbits and rats. In rabbits, the order of the hyperthermic activities was allyl-norLSD greater than LSD greater than LEO, LAE, nor-LSD, and this order was parallel to that of 5-hydroxytryptamine-like activities of these compounds which was previously studied. However, the order was LAE greater than LSD greater than norLSD IN RATS. The hyperthermic effect of LSD in rabbits was attenuated by methysergide, but not by atropine when these drugs were intraventricularly administered. These results suggest the possibility that the metabolites of LSD contribute to the hyperthermic effect of LSD in rats but not in rabbits, and support the idea that 5-HT receptors are involved in the hyperthermia induced by LSD in rabbits.