Fast axoplasmic transport of noradrenaline and dopamine in mammalian peripheral nerve.

Abstract

A fast transport of noradrenaline [NA, norepinephrine] at a velocity of 392 mm/day was found in the cat peroneal nerve using a double-ligation technique and a new sensitive radio-enzymatic assay for catecholamines. The velocity of NA transport is sufficiently close to that of 410 mm/day found for labeled proteins and polypeptides to be considered as moving down within the nerve fibers by the same transport mechanism. Dopamine (DA) moved down by anterograde transport at a fast but not well defined rate. Disulfiram, a dopamine-.beta.-hydroxylase inhibiting agent, reduced NA levels and increased DA both in control nerve segments and within the portion of the nerve isolated by ligations where NA-containing dense-core vesicles are present. A dynamic turnover of NA and DA in the dense-core vesicles as they are transported in the axons is likely.