Stress-induced hyperglycemia and hypoinsulinemia are suppressed by sulfonylurea: predominant role of insulin

ABSTRACT

Based on the in vitro blockade of adrenal catecholamines release by sulfonylurea, we searched for an anti-stress activity of this drug. Stress-induced hyperglycemia and insulin inhibition were employed sadrenergic stress indicators. A standard dose of the oral sulfonylurea glipizide (200 micrograms/100 g), administered 15 min before a 1-h restraint stress to intact or 80 percent pancreatectomized rats, produced otalsuppression of the stress-induced hyperglycemia-hypoinsulinemia, an effect followed by a significant post-stress hypoglycemia of 1 h duration. The latter effect was elicited by all the sulfonylureas assayed. In the 80 percent pancreatectomized rats, glipizide nearly halved the increases in plasma catecholamines at 30 min of stress, but did not modify those attained at 60 min, when glycemia was decreasing and insulinemia was still increasing. Moreover, behavioral experiments in intact stressed rats showed that the adrenergic overt behavior inhibition caused by propranolol was not produced either by glipizide or insulin, reinforcing that glipizide affect was not mediated by catecholamine inhibition. These findings suggest a blockade of...