1. Solid lines show changes in plasma glucose that occur in normal subjects in response to acute intravenous insulin administration. Note the rapid recovery of glucose levels mediated by intact counterregulatory mechanisms. The dashed lines show the response to insulin-induced hypoglycemia in patients with deficiencies of the counterregulatory mechanisms induced as follows: A: Somatostatin infusion (inhibits both glucagon and growth hormone [GH] release). B: Somatostatin infusion plus GH infusion (now with functional isolated glucagon deficiency). C: Somatostatin infusion plus glucagon infusion (isolated GH deficiency). Note return of glucose response to normal, implying that glucagon is the main counterregulatory hormone. D: Bilateral adrenalectomy, leading to epinephrine deficiency, or infusion of phentolamine plus propranolol (alpha and beta blockers, respectively). Note that such deficiencies cause no major abnormality in response to induced hypoglycemia when glucagon is present. E and F: Sympathetic modulation (by phentolamine plus propranolol in E and by bilateral adrenalectomy in F), which seriously impairs the ability to respond to hypoglycemia in the patient made glucagon-deficient by somatostatin infusion. (Data from Clarke WL, Santiago JV, Thomas L, et al. The role of adrenergic mechanisms in recovery from hypoglycemia in man: studies with adrenergic blockade. Am J Physiol 236:E , 1979; Gerich J, Davis J, Lorenzi M, et al. Hormonal mechanisms of recovery from insulin-induced hypoglycemia in man. Am J Physiol 236:E , 1979; Rizza RA, Cryer PE, Gerich JE. Role of glucagon, epinephrine and growth hormone in human glucose counterregulation: effects of somatostatin and adrenergic blockade on plasma glucose recovery and glucose flux rates following insulin-induced hypoglycemia. J Clin Invest 64:62-71, 1979.)
Source: Hypoglycemic Disorders, Greenspan's Basic & Clinical Endocrinology, 10e
Citation: Gardner DG, Shoback D. Greenspan's Basic & Clinical Endocrinology, 10e; 2017 Available at: Accessed: October 04, 2017
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