Electrophysiological evaluation of the effects of naftidrofuryl on skeletal muscle reinnervation in the rat

Abstract

The effects of naftidrofuryl on the reinnervation of the rat gastrocnemius muscle after its denervation by localized freezing of the sciatic nerve were tested with electrophysiological techniques. Daily intraperitoneal injections of 30 mg/kg of naftidrofuryl do not increase the rate of axonal regeneration since early signs of reinnervation appeared as in controls around the 10th day after surgery. However, axonal sprouting is markedly increased since the percentage of muscle fibers with polyneuronal innervations was almost twice as high as in controls at the 15 and 21 day postoperative stages. The promoting effects of naftidrofuryl on polyneuronal innervation which gives rise to a redundant innervation during the first period of reinnervation constitutes an improvement of motor function which might be efficient for treatment of nerve injury and neuropathies.

Reinnervation of muscles after transection of the sciatic nerve in adult rats

“…Seven weeks after the nerve lesion, about 20% (LGC and TA) to 40% (SOL) of the motor endplates were polyneuronally innervated, and these figures decreased to around 10% in all three muscles at 21 weeks. Similar results were obtained by Pécot‐Dechavasinne and Mira,25 and Ribchester,29 in the gastrocnemius muscle after localized freezing of the sciatic nerve. Östberg et al24 demonstrated in cross‐innervation experiments that over‐innervation of a fast muscle leads to a significant portion of the motor endplates becoming polyneuronally innervated.…”