RESUMO
Albuterol (salbutamol), a beta 2 adrenoreceptor agonist, produced a dose-dependent decrease in food intake in Sprague-Dawley male control rats. This phenomenon appeared to be impaired in streptozotocin (STZ) diabetic rats. The density of beta 2 adrenoreceptors in the ventromedial hypothalamic nucleus was increased as a function of diabetes. In contrast, a decrease in the ventromedial hypothalamic 5-hydroxyindoleacetic acid (5-HIAA) concentration, an indicator of serotonin (5-hydroxytryptamine; 5-HT) release or turnover rate, was observed in this disease state. Neither the beta 2 adrenoreceptor level nor 5-HT turnover rate was altered in the periventricular hypothalamic nucleus of STZ diabetic rats. The concentrations of 5-HT in both hypothalamic nuclei were unchanged in these animals. Neurochemical and behavioral abnormalities featured in the diabetic state were reversed with institution of insulin therapy. These data conclude that diabetes-related impairment in the anorexic action of albuterol may be due to derangements in ventromedial hypothalamic beta 2 adrenoreceptor function.