A method for the demonstration of adrenergic nerve fibres in peripheral nerves

The uptake and retention of [3H]noradrenaline in rat sciatic nerves after ligation

The uptake and retention of [3H]noradrenaline (3H-NA) was examined in sciatic nerves of albino rats. In the 1 cm part of nerve proximal to a 12 hr ligation the uptake and retention of exogenous noradrenaline was about 4 times the uptake in 1 cm of normal unligated nerves. Treatment with reserpine 10 hr before killing caused a marked decrease in the estimated amount of 3H-NA, while injection of nialamide 15 min before 3H-NA administration in ligated, reserpine-treated animals caused a somewhat larger uptake and retention of 3H-NA in the nerve part above the ligation. Protriptyline, a blocker of the “membrane pump”, was approximately 3 times less effective in 12 hr-ligated nerves than in unligated nerves, indicating a reduced efficiency of the “membrane pump” in the distended axons above a ligation.