Neural regulation of adrenal chromaffin cell function in the mouse: fate and distribution of [3H]dopamine in denervated adrenal medulla.

The distribution and time course of appearance and decline of radioactivity in denervated adrenal medulla of mice injected with [3H]dopamine was examined by autoradiography. Radioactivity irradiated from [3H]dopamine was increased from 7.5 min to 30 min, then decreased rapidly in both adrenaline-storing (A) cells and noradrenaline-storing (NA) cells of either intact or denervated adrenals. In subcortical A cells, the incorporation of radioactivity was increased by denervation while in NA cells and in A cells in the center of the medulla, the increment was not significant. In the denervated adrenals, the decline of [3H]dopamine-derived radioactivity was slower than that in the intact gland. The denervation increased the gradient in radioactivity from the surface to the center of the medulla. The present results suggest that the sensitivity to neuronal suppression of dopamine uptake in subcortical A cells is different from that in A and NA cells in the rest of the gland. The results also indicate a functional heterogeneity within a single type of chromaffin cells.