Pyretogenic effect of lysergic acid diethylamide

Introduction

Earlier work on ergot alkaloids established many peripheral autonomic and oxytocic effects, yet lysergic acid diethylamide (LSD) differs markedly in producing prominent hallucinogenic activity rather than those classical peripheral actions. While studying LSD in intact, normal rabbits, the investigators observed pronounced hyperpnea, which prompted them to examine whether LSD also raises body temperature. Previous reports of thermoregulatory and autonomic effects of LSD in animals and humans had been inconsistent, so clarifying any pyretogenic (fever-producing) action was of interest. This study set out to characterise the pyretogenic effect of LSD across several species (rabbits, dogs, cats), to document its time course and route-dependence, and to probe mechanisms by testing a range of pharmacologic interventions. The authors also explored peripheral temperature changes (skin and ear) to assess whether altered heat loss could explain any rise in core temperature, and they evaluated whether various drugs could antagonise the response.