The Effect of Reserpine and Tetrabenazine on the Accumulation of Noradrenaline in the Rat Sciatic Nerve after Ligation

The accumulation of noradrenaline (NA) in the rat sciatic nerve after ligation was studied at different intervals after the administration of reserpine and tetrabenazine. The histochemical fluorescence method of Hillarp and coworkers was used. It was found that the two drugs were both able to abolish the NA fluorescence above and below both single and double ligations. Pretreatment with nialamide prevented the disappearance of NA occurring after reserpine. The reappearance of NA above a 1 hr ligation of the sciatic nerve occurred 15–18 hrs after an intraperitoneal injection of reserpine. The first signs of the reappearance was observed above a high ligation about 3 hrs before it could be seen above a ligation performed about 2 cm lower. The same pattern of recovery of NA in the sciatic nerve was observed in animals treated locally with reserpine on the ganglia, from which the adrenergic nerves in the sciatic nerve take their origin. However, the fluorescence of NA in these animals usually reappeared about 3 hrs earlier than in systemically treated animals. The restituted NA could be abolished by a second dose of reserpine. In double ligated rats recovery of NA after reserpine could be observed only above the upper ligation. After tetrabenazine, however, double ligated nerves regained the NA content almost completely above both lesions within 12–15 hrs. The results give strong support to the view that the amine storage granules are manufactured in the cell body and transported down the axons to the terminals.