Neural Regulation of Adrenal Chromaffin Cell Function in the Mouse--stress Effect on the Distribution of [3H]dopamine in Denervated Adrenal Medulla

Effects of adrenal denervation and stress on the distribution of radioactivity in the adrenal medulla after [3H]dopamine injection was studied by light microscopic autoradiography. Denervation of the adrenal gland abolished the stress (restraint plus water immersion) induced degranulation of adrenal chromaffin cells and decreased uptake of [3H]dopamine. Denervated chromaffin cell of stress mice incorporated as high radioactivity as those of no stress mice. Adrenal denervation increased the uptake in adrenaline-storing (A) cells but not in noradrenaline-storing (NA) cells. The characteristic distribution of radioactivity (high radioactivity along the cortico-medullary junction) was reinforced by adrenal denervation. Under stress conditions, increase in pituitary adrenocortical system did not enhance the uptake of [3H]dopamine in chromaffin cell while increase in nerve activity suppressed the uptake. Spontaneous activity of the splanchnic nerve to adrenal chromaffin cells suppresses the uptake of [3H]dopamine. The neural influence is stronger on A cells than on NA cells. Chromaffin cells in the subcortical zone are more intensely controlled by the neural influence than those in the central zone.