Absence of dopamine-beta-hydroxylase in some catecholamine-containing sympathetic ganglion cells of the dog: evidence for dopaminergic autonomic neurones.

Previous pharmacological and biochemical findings have suggested the presence of dopaminergic vasomotor neurones in the sympathetic outflows to the kidney and the digits of the dog. In the present study, we have used histochemical techniques to compare the distributions of catecholamines and dopamine-beta-hydroxylase-like immunoreactivity in ganglion cell bodies of the sympathetic chain. The results indicate that some neurones in the ganglia supplying the kidney and the hindlimb store a catecholamine but lack dopamine-beta-hydroxylase. This finding supports the existence of dopaminergic sympathetic neurones.