The influence of beta-adrenoceptor blocking drugs with and without intrinsic sympathomimetic activity on the hormonal responses to hypo- and hyperglycaemia.
1 The effects of oral doses of pindolol (15 mg), metoprolol (200 mg) and propranolol (160 mg) on the response to insulin-induced hypoglycaemia and an oral glucose load were investigated. 2 Serum insulin and serum C-peptide secretion in response to a glucose load were inhibited (2P less than 0.01) by metoprolol and propranolol but not by pindolol. 3 During hypoglycaemia metoprolol and propranolol inhibited the clearance of insulin (2P less than 0.01) and caused a delay of glucose nadirs. 4 Adrenaline secretion during hypoglycaemia was markedly increased by metoprolol and propranolol but not by pindolol. 5 The counterregulatory response of growth hormone, ACTH and cortisol was increased following metoprolol and propranolol but not after pindolol. 6 The hypoglycaemic symptoms and signs showed a prevalence of sweating and prolonged changes in skin conductivity whereas palpitations were not observed during beta-adrenoceptor blockade. Asymptomatic hypoglycaemia did not occur. 7 The absence of unphysiological rises in adrenaline, growth hormone, ACTH and cortisol supports the use of a beta-adrenoceptor blocker with intrinsic sympathomimetic activity.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D002395:Catecholamines / Q000097:blood; D005951:Glucose Tolerance Test; D006339:Heart Rate; D006728:Hormones / Q000097:blood*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood*; D007003:Hypoglycemia / Q000097:blood*; D007328:Insulin / Q000097:blood; D008297:Male; D013566:Sympathomimetics / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D002096:C-Peptide; D002395:Catecholamines; D006728:Hormones; D007328:Insulin; D013566:Sympathomimetics