Pharmacological action of mazindol on behaviors and metabolism

To elucidate the mechanism of the action of mazindol, an anorectic drug, mazindol effects on behaviors of rats such as feeding, drinking and activities were examined. Mazindol (40 mg/100 g of diet) addition to the diet elicited the transient decrease in food and water intakes, and increases in Animex and running wheel activities compared to those behaviors seen before the mazindol addition. The mazindol addition essentially did not affect the circadian rhythms of the above behaviors. Continuous infusion of mazindol (1-10 ng/h) into the brain reduced the total food intake and increased the light period food intake. The strongest effect of mazindol on food intake was observed when it was infused into a site of median eminence which was 2 mm posterior to the suprachiasmatic nucleus of the hypothalamus. This fact suggests that the site of the anorectic action of mazindol might be located in this area. Since food efficiency (=body weight increase per day/food intake per day) reduced during the period of mazindol addition to the diet in the above experiment, metabolic alterations due to mazindol were examined in rats. The results suggest that mazindol administration enhances degradations of proteins and amino acids and increases gluconeogenesis in the liver.