Behavioral effects of pergolide mesylate on food intake and body weight

In a crossover design experiment, pergolide mesylate significantly suppressed food intake and body weight in spayed female rats. Inhibition of food intake by a constant dose of pergolide progressively diminished with repeated administrations. Pergolide continued to suppress body weight with no indications of tolerance. When pergolide was discontinued, body weight increased sufficiently to compensate for the loss and failure to gain during drug treatment. A second experiment investigated the observation that animals injected first with vehicle showed greater anorexia when subsequently injected with pergolide than did animals injected first with pergolide. In addition, tolerance was further assessed by administering on two occasions a higher dose of pergolide. Following chronic pergolide treatment, this dose was insufficient to reinstate anorexia; however, after a period of abstinence, this dose produced anorexia comparable to that observed at the beginning of pergolide treatment. Due to pergolide mesylate's action as a postsynaptic dopamine agonist, a dopaminergic neural system is implicated in pergolide induced anorexia.