Synthesis and utilization of catecholamines in the rat superior cervical ganglion following changes in the nerve impulse flow

Abstract

The nerve impulse flow to the noradrenaline nerve cell body region of the superior cervical ganglion and to the noradrenaline nerve terminals of the salivary glands was decreased and increased by decentralization and preganglionic electrical stimulation, respectively. The concentrations of dopamine, noradrenaline, and their primary deaminated metabolites (DOPAC, DOPEG) in the ganglion were not changed during the first day after the decentralization but were increased following preganglionic stimulation, particularly that of DOPAC. The disappearances of dopamine and noradrenaline afterα-methyltyrosine and the disappearance of noradrenaline after inhibition of the dopamine-β-hydroxylase were not changed by decentralization or stimulation. The accumulation of dopamine following inhibition of the dopamine-β-hydroxylase was somewhat lowered by decentralization and was markedly enhanced by stimulation. In the noradrenaline nerve terminals of the salivary glands, preganglionic sympathetic stimulation decreased and increased the concentration of noradrenaline and dopamine, respectively. Thus, nerve impulses stimulated the tyrosine hydroxylase activity in the cell body region and the axon terminals of the noradrenaline neurons but they increased the utilization of noradrenaline only in the terminals.