THE HYPOGLYCEMIC AND EOSINOPENIC RESPONSE TO INSULIN: A TEST FOR PITUITARY-ADRENAL INSUFFICIENCY

Abstract

THE relationship between the activity of the adrenal cortex and the number of circulating eosinophils has been amply demonstrated. Forsham et al. (1) have shown that, in normal humans, the administration of ACTH (which stimulates the adrenal cortex) andcompound E or compound F (active corticoids formed by the adrenal cortex) causes an eosinopenia. In addition, Recant et al. (2) showed that injections of 0.3 cc. of epinephrine subcutaneously produced a marked drop in eosinophils after four hours, averaging 63 per cent, with a range between 40 and 80 per cent, whereas controls injected with saline did not show this effect. In patients with adrenal insufficiency, the fall in eosinophil count in response to adrenalin was less than 40 per cent. In 1941, Fraser, Albright and Smith (3) showed that insulin, 0.1 unit per kilo intravenously, produced a response in normal subjects characterized by a maximum drop in blood sugar at about 30 minutes and by a return to the fasting blood sugar level within 90 to 120 minutes. Patients with adrenal and pituitary insufficiency showed increased sensitivity toinsulin and also a failure of blood sugar to rise to the pre-test levels within 90 to 120minutes. These observers suggested the use of 0.05 unit of insulin per kilo in such patients in order to prevent a serious insulin reaction. Nevertheless, the extreme sensitivityof certain patients suffering from adrenal or pituitary insufficiency has discouraged many from using this test.