The effects of the serotonin1A receptor agonist buspirone on tolbutamide-induced hypoglycemia in rats.

The effects of the serotonin1A(5-HT1A) receptor agonist buspirone on hypoglycemia elicited by tolbutamide were investigated in rats. Buspirone, at doses not affecting plasma glucose levels, inhibited the hypoglycemic effects of tolbutamide. The inhibitory effects of buspirone on tolbutamide-induced hypoglycemia were antagonized by the 5-HT1A receptor antagonist pindolol. As tolbutamide is known to induce hypoglycemia by facilitating insulin release, the effects of buspirone on a tolbutamide-induced increase in serum insulin levels were also studied. However, buspirone did not affect tolbutamide-induced insulin release. Adrenodemedullation inhibited the effects of buspirone. These results suggest that buspirone inhibits tolbutamide-induced hypoglycemia mediated by the 5-HT1A receptor, and adrenaline release may be involved in the effects of buspirone.