LOW AMBIENT-TEMPERATURE AND NEUROENDOCRINE RESPONSE TO HYPOGLYCEMIA IN MEN

Nutritional factors, such as an excess or a deficiency of glucose, pla y an important role in neuroendocrine regulations, Hormonal and metabo lic responses to hypoglycemia were examined in healthy non-obese volun teers under conditions of low ambient temperature, Hypoglycemia was in duced by intravenous injection of insulin in two randomized trials per formed at room temperature and at 4 degrees C, At room temperature, th e typical neuroendocrine response to hypoglycemia was established, The increases of ACTH, beta-endorphin, growth hormone and cortisol in res ponse to insulin hypoglycemia failed to be modified by low ambient tem perature, Acute cold exposure significantly reduced epinephrine and to tally inhibited prolactin response to insulin-induced hypoglycemia, In spite of significant changes in epinephrine response to hypoglycemia at low ambient temperature, no striking differences in plasma glucose levels compared to those measured at room temperature were observed, H owever, under conditions of low temperature the reestablishment of nor moglycemia was delayed, No changes in free fatty acids were found unde r our experimental conditions, The presented data show that low ambien t temperature exerts selective effects on some neuroendocrine and meta bolic parameters.