Abstract

A number of compounds containing a phenylethylamine structure were tested in rats to determine the potency of their anorexigenic effects (as measured by depression of hunger-induced food intake) and of their behavioral effects (as measured by effects on continuous avoidance responding). All of the compounds tested were effective in reducing the food intake of hungry rats. The most potent compounds were fenfluramine and p-chloroamphetamine, with molar poteneies one-third greater than that of d-amphetamine, whereas the least potent compound was p-hydroxyamphetamine with a molar potency less than 6% that of d-amphetamine. In the behavioral tests, the compounds fell into three classes, either increasing, decreasing or having no effect on the rate of avoidance responding. The majority of the compounds acted as stimulants to increase the rate of avoidance responding, with the most potent one, methamphetamine, having a molar potency 3 times that of amphetamine. The least potent stimulant compound was phendimetrazine, with a molar potency approximately 1/10 that of amphetamine. Fenfluramine, p-methylamphetamine and p-chlorobenzphetamine were depressant in action, whereas chiorphentermine, benzphetamine and p-hydroxyamphetamine had no significant effects on avoidance responding.