The effect of local application of vinblastine or cholchinine on acetylcholine accumulation in rat sciatic nerve.

The accumulation of acetylcholine (ACh) following nerve crush was inhibited by high concentration of colchicine (10(-1), 10(-2 M) and vinblastine (10(-2)-10(-4 M) in a dose-dependent manner. The two mitotic inhibitors were effective both when applied to axons (subepineural injections) and to perikaraya (injections into the lumbar intumescence). The results indicate that mitotic inhibitors, when applied locally to cholinergic motor neurons, may block the proximo-distal transport of ACh. The possibility is discussed that this blockade is caused by an interference with a microtubule mechanism in the axons. Evidence for an increased local synthesis of ACh near the site of injection into nerves also obtained with the highest concentrations of either substance used.