[Effects of acetyl-L-carnitine on the recovery of hindlimb movement afterspinal cord injury in rats and its mechamism].

To observe the effects of different doses of acetyl-L-carnitine (ALC) on hindlimb motor function and spinal cord tissue structure in rats with spinal cord injury. The study will provide theoretical and experimental evidences for acetyl-L-carnitine's clinical treatment.Fifty-five SD rats aged 8-10 weeks were randomly divided into high, medium and low-dose drug intervention (SCI + ALC) group, injury group (SCI) and sham group for behavioral evaluation, MAD and SOD detection, as well as HPLC detection and HE staining. BBB scores and Rivlin experiments were performed to evaluate hindlimb motor function in each group. The morphology and structure of spinal cord tissue was detected by HE staining. Another 9 rats were randomly divided into Sham group, SCI group and ALC group for TUMEL detection of apoptosis.The BBB scores of the high, medium, and low dose SCI+ALC groups were significantly higher than those in the SCI group. The medium and high-dose ALC groups had significant differences (P＜0.01), and the hindlimb motor function was significantly improved in rats. The maximum tilt angle of the Rivlin experiment was observed. The SCI+ALC group had a significantly increased angle compared with the SCI group (P＜0.05), the medium and high-dose ALC group had a significant difference (P＜0.01). Compared with the SCI group, the tissue structure of ALC high-dose group was improved significantly, the number of inflammatory cells and red blood cells was decreased, and the nucleolus of the nerve cells was unclear. The SOD activity of the SCI+ALC group was significantly higher than that of the SCI group, while the MDA content was significantly decreased(P＜0.05), the middle and high dose ALC groups were significantly different (P＜0.01). HPLC chromatogram showed that the SCI+ALC fresh serum sample and the ALC standard solution had the same absorption spectrum at 260 nm, while the Sham group and SCI group serum samples did not show spectral values there, which indicated that the same substance as the standard existed in the sample of SCI+ALC group. TUNEL staining showed that the apoptosis signal was occasionally seen in the sham group, and the apoptosis signal was significantly decreased in the ALC high-dose group compared with the SCI group(P＜0.05).ALC can promote the recovery of hindlimb motor function in rats with spinal cord injury, inhibit oxidative stress and apoptosis, and repair the damaged spinal cord tissue.