Increased feeding in rats treated with chlordimeform and related formamidines: a new class of appetite stimulants.

Low doses of the formamidine pesticide, chlordimeform (CDM) induce voracious daytime feeding in non-food deprived rats. Following CDM (10 mg/kg), food intakes were five times control intakes after 3 h and 1.1 times control intakes after 24 h. Other selected formamidines, such as the N-demethylated metabolite of CDM, and amitraz, increased 3-h food intake by two and five times control intake, respectively. Anorexia accompanied by excessive CNS stimulation was noted with higher doses of CDM (above 40 mg/kg) and other formamidines. This contrasts with the sedation usually observed with high doses of other structurally diverse appetite stimulants. In addition, hyperphagia was not observed with other CNS stimulants or local anesthetics such as amphetamine, cocaine, and holocaine. Thus the formamidines constitute a new class of appetite stimulants, which should prove to be useful agents for the study of feeding behavior.