Effects of metyrapone and a combined alpha- and beta-adrenergic blockade on plasma glucose recovery from insulin-induced hypoglycaemia in pigs.
The recovery of plasma glucose from insulin-induced hypoglycaemia was investigated in growing pigs during an inhibition of corticosteroid secretion (metyrapone infusion), an alpha- and beta-adrenergic blockade (phentolamine and propranolol infusion) or a combination of both treatments. In pigs which received an infusion of metyrapone for 4 h before and 3 h after a bolus injection of insulin (0.1 IU/kg body-weight), the plasma glucose response did not differ significantly from control animals. The infusion of phentolamine and propranolol (in each case 120 micrograms/kg/h for 3 h after a priming dose of 100 micrograms/kg) starting at the time of insulin injection significantly attenuated the restoration of normoglycaemia. An additional infusion of metyrapone increased this effect significantly only at the end of the experiment. The results indicate that adrenergic mechanisms are involved in the glucose counterregulation after an insulin-induced hypoglycaemia in pigs and the glucocorticoid secretion may become critical when the catecholamine response is impaired.
D000305:Adrenal Cortex Hormones / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism; D005260:Female; D007003:Hypoglycemia / Q000097:blood* / Q000139:chemically induced; D007328:Insulin; D008297:Male; D008797:Metyrapone / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D013552:Swine; D013565:Sympatholytics / Q000494:pharmacology*
D000305:Adrenal Cortex Hormones; D001786:Blood Glucose; D002395:Catecholamines; D007328:Insulin; D013565:Sympatholytics; D011433:Propranolol; D010646:Phentolamine; D008797:Metyrapone