Studies on the dual action of guanethidine in sympathetic nerves.

Abstract

P. Lundborg and R. E. Stitzel. Studies on the dual action of guanethidine in sympathetic nerves. Acta physiol. scand. 1968. 72. 100–107. Evidence is presented indicating that guanethidine inhibits both the transport of amines through the nerve cell membrane and an uptake mechanism present in amine-storing granules. In vivo the onset of membrane pump blockade is the more rapid process, but inhibition of granular uptake is more long-lasting. In vitro studies demonstrate that guanethidine can inhibit the uptake of 14C-adrenaline into bovine adreno-medullary granules. The depletion of 3H-metaraminol seen after guanethidine administration may result from a reserpine-like action on the amine storage granules and/or a protriptyline-like action on the membrane pump. It is suggested that the membrane pump inhibiting ability possessed by guanethidine, but not reserpine. may account for the sympathomimetic activity and exogenous amine potentiation which often accompanies guanethidine, but not reserpine, administration.