Adrenal Medullary Secretory Response to Pontine and Mesencephalic Stimulation in the Rat

Abstract

Adrenal medullary secretion in response to electrical stimulation of the pons and midbrain was investigated in pentobarbital-anesthetized rats. Adrenal venous blood samples were collected and analyzed for epinephrine and norepinephrine by the fluorometric method. Stimulation of the dorsolateral areas of the pons and midbrain resulted in a significant increase in epinephrine secretion with or without a significant increase in norepinephrine secretion. Most of the responsive areas were localized near the main sensory nucleus and motor nucleus of the trigeminal nerve. It may be suggested that in the pons and midbrain there exist central nervous system mechanisms for the regulation of the adrenal medullary secretion.