INTERACTION EFFECTS OF D-AMPHETAMINE TREATMENT AND AMBIENT-TEMPERATURE ON RATS FOOD-INTAKE

The thermoregulatory theory of hunger posits that rats placed in a cold environment should increase the amount of food intake, while rats placed in a hot environment should decrease their food intake. d-Amphetamine causes hyperthermia among rats kept at warm ambient temperature and results in hypothermia among animals kept in a cold environment. d-Amphetamine-caused-hyperthermia should therefore result in decreased eating behavior, and d-amphetamine-caused hypothermia should result in increased eating behavior. One must take into account the fact that d-amphetamine is an anorexic drug. The interaction between ambient temperature, body temperature and food intake were tested on groups of rats injected with various doses of d-amphetamine (1.5-15 mg/kg) and placed in ambient temperatures ranging from 4-37.degree. C. No increase in food intake was revealed under any dosage or temperature condition. The decrease in food intake found with d-amphetamine treated animals could not be explained in the thermoregulatory theory of hunger. d-Amphetamine anorexic effects and thermal effects are probably mediated by different mechanisms.