Subcellular distribution of [3H]amphetamine and [3H]guanethidine and their interaction with adrenergic neurons

Abstract

The subcellular distribution of [3H]amphetamine and [3H]guanethidine and their interaction with each other and with noradrenaline binding sites have been examined. The ratio p/(p + s) × 100, an indication of affinity for noradrenaline storage particles, for [3H]amphetamine and [3H]guanethidine was 12% and 57% respectively. Protriptyline, a substance which inhibits amine transport mechanism at the level of the cell membrane, i.e. the membrane pump, and reserpine, an agent which impairs incorporation of amines into the storage particles in the adrenergic nerve fibre, inhibited the uptake and storage respectively, of [3H]guanethidine more than that of [3H]amphetamine. Retention of [3H]guanethidine by rat salivary glands was markedly decreased by sympathetic denervation of the glands while that of [3H]amphetamine was not. The results suggest that guanethidine possesses a much higher affinity for noradrenaline binding sites than amphetamine.