Effect of insulin on central catecholamines.

The effects of insulin on levels and turnover of catecholamines in the hypothalamus and medulla oblongata were investigated. Systemic or intraventricular administration of insulin had no effect on catecholamine levels, but increased the turnover rate of norepinephrine and epinephrine. Insulin induced a dose-related increased release of norepinephrine, epinephrine and dopamine from hypothalamic slices. These results indicate that the effects of insulin on central catecholamines are elicited by its action in the brain.