Norepinephrine kinetics during insulin-induced hypoglycemia.

Norepinephrine (NE) kinetics (plasma appearance rate, clearance, and forearm extraction) were measured during insulin-induced hypoglycemia in six healthy subjects. NE clearance did not change during hypoglycemia, indicating that the increase in plasma NE during hypoglycemia is due to an increased plasma appearance rate of NE. Forearm extraction of 3H-NE and of endogenous plasma epinephrine decreased significantly during hypoglycemia, probably due to an increase in regional blood flow.