乙酰左旋肉碱对大鼠脊髓损伤的保护作用

Protective effect of acetyl-l-carnitine on spinal cord injury of rats

目的：研究乙酰左旋肉碱（Acetyl-1-carnitine,ALC）对大鼠脊髓损伤（spinal cord injury,SCI）的保护作用,并探讨其作用机制。方法：成年雄性SD大鼠36只,体重200~250 g,随机分为三组：假手术组（Sham组）、脊髓损伤组（SCI组）、乙酰左旋肉碱组（ALC组）每组12只。Sham组只暴露脊髓,不打击;SCI组采用Allen＇s重物打击法制备脊髓损伤模型;ALC组在打击脊髓后15 min腹腔注射剂量为300 mg/kg的乙酰左旋肉碱。Sham组和SCI组均腹腔注射相同体积的生理盐水。24 h后取出各组大鼠脊髓组织进行检测。用分光光度法检测各组脊髓组织中丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性,用Western Blot检测凋亡蛋白caspase-3的表达量,用TUNEL法观测神经细胞的凋亡状况。结果：与Sham组相比,SCI组脊髓组织中MDA含量明显升高,SOD活性明显降低,凋亡蛋白caspase-3表达量明显增加,神经细胞的凋亡比例明显增加（P〈0.01）;与SCI组相比,ALC组脊髓组织中MDA含量明显降低,SOD活性明显增加,凋亡蛋白caspase-3表达量明显降低,神经细胞的凋亡比例明显减少（P〈0.01）。结论：乙酰左旋肉碱可以减轻氧化损伤,抑制神经细胞凋亡,对脊髓损伤有保护作用。

Objective：To study the protective effect of acetyl-1-carnitine（ALC） on spinal cord injury in rat and the possible mechanisms therein.Methods：Thirty-six male adult SD rats（200- 250 g） were randomly divided into three groups（n = 12）：Sham surgery group（Sham group）,spinal cord injury group（SCI group） and ALC treatment group（ALC group）.Rats in Sham group just received spinal cord exposure without percussion;rat models in SCI group were induced according to Allen＇s method（using a weight-drop device）.Rats in ALC group received ALC（300 mg/kg）through intraperitoneal injection（i.p.） 15 min after SCI surgery.Rats in Sham and SCI groups received the same volume of physiological saline.Spinal cord of the rats in all groups were removed for detection 24 h after treatment.The level of Malondialdehyde（MDA） and the activity of superoxide dismutase（SOD） in spinal cord tissues were detected using spectrophotometer.Neural apoptosis was detected by TUNEL staining and the expression level of caspase-3 was detected using Western Blot.Results：Compared with Sham group,the level of MDA,the expression level of caspase-3,the neuronal apoptosis ratio in SCI group were obviously increased,while activity of SOD in SCI group was obviously decreased（P〈 0.01）.Compared with SCI group,the level of MDA,the expression level of caspase-3,the neuronal apoptosis ratio in ALC group were obviously decreased,while the activity of SOD in ALC group was obviously increased（P〈 0.01）.Conclusion：Acetyl-1-carnitine can protect spinal cord injury through relieving oxidative damage and restraining neural apoptosis.