TREATMENT WITH ACETYL-L-CARNITINE EXERTS A NEUROPROTECTIVE EFFECT IN THE SCIATIC NERVE FOLLOWING LOOSE LIGATION: A FUNCTIONAL AND MICROANATOMICAL STUDY

Peripheral neuropathies are characterized by chronic painful syndromes accompanied by allodynia, hyperalgesia and altered nerve functionality. Nerve tissue degeneration represents the microanatomical correlate of peripheral neuropathies. This study has investigated, in rat with loose ligation of sciatic nerve, as animal model of peripheral neuropathy, hyperalgesic effects and morphological alterations in the distal zone of ligated nerve. Possible protective effects elicited by treatment with acetyl-L-carnitine (ALCAR) or with gabapentin were also assessed. Axonal injury, reduction of myelin deposition and accumulation of inflammatory cells were detected in the distal zone of damaged nerve. A decrease of phosphorylated 200- kDa neurofilament (NFP) immunoreactivity and a redistribution in small clusters of myelin basic like-protein (MBP) immunoreactivity were observed in the distal part of ipsilateral nerves. Treatment with ALCAR (100 mg/kg/die intraperitoneally - i.p.) and gabapentin (70 mg/kg/die i.p.) administered bis in die, daily for 14 days induced a significant pain relieving effect. ALCAR, but not gabapentin, countered to some extent neuromorphological changes of nerve and increased axonal NFP immunoreactivity. These findings indicate that both ALCAR and gabapentin significantly countered the hypersensitivity related to neuropathic lesions. The observation of thepositive ALCAR effect on axonal and myelin sheath alterations in damaged nerve supports the use of the compound as neurorestorative agent against neuropathies through mechanism(s) similar to those focused in this study.