Effect of acetyl-L-carnitine on axonal sprouting following donor nerve injury distal to an end-to-side neurorrhaphy model.

This study investigated the hypothesis that acetyl-L-carnitine (ALCAR) could have a significant effect on nerve regeneration after end-to-side neurorrhaphy. The ability of the ALCAR to enhance nerve regeneration in combination with various types of donor nerve injury distal to the coaptation site was also determined. Twenty-five Sprague-Dawley rats were randomized to five groups of five animals each, in which three different types of donor injury (crush, ligation, and transection injury) distal to the coaptation site were executed (groups C, D, and E, respectively). Animals in group A (placebo) and group B underwent a standard end-to-side neurorrhaphy. Animals from groups B to E received a daily intraperitoneal injection of 50 mg/kg/d of ALCAR, and a placebo was injected in place of ALCAR in animals in group A. Administration of acetyl-L-carnitine alone did not prove to be a significant stimulus for regeneration, as concluded after comparison among the two noninjury models of the donor nerve (groups A and B). Indeed, the combination of an injury model of the donor nerve (crush injury) with administration of acetyl-L-carnitine proved to be a significantly more potent stimulus for regeneration than the control (placebo) group, as measured by behavioral, muscle morphometric, electrophysiological, and histomorphometric studies.