AXONAL-TRANSPORT OF ADRENALINE, NORADRENALINE AND PHENYLETHANOLAMINE-N-METHYL TRANSFERASE (PNMT) IN SYMPATHETIC NEURONS OF THE COD, GADUS-MORHUA

The axonal transport of adrenaline, noradrenaline and phenylethanolamine‐N‐methyl transferase (PNMT) has been studied in vivo in sympathetic neurons of the splanchnic nerve in the cod, Gadus morhua. Adrenaline and noradrenaline are transported at a mean axonal transport rate of 16 mm/day. After correction for a non‐mobile fraction of adrenaline and noradrenaline, which does not contribute to the amine accumulation proximal to a ligature, a maximal rate of transport was calculated to about 45 mm/day for both amines. The increased level of catecholamines in front of a ligature could be depleted by reserpine treatment, which strongly suggests that both amines are stored in granules. PNMT is transported at a slow rate of 2 mm/day. The subcellular distribution of the cod PNMT was exclusively non‐particular. The cod PNMT was further characterized by studying substrate specificity, temperature and pH optima. It is concluded that adrenaline and noradrenaline, stored in granules, are transported in a proximo‐distal direction at a high rate compared to PNMT. © 1979 Scandinavian Physiological Society