大鼠颈脊髓半侧挫伤模型的建立及其组织学变化的研究

Establishment of unilateral cervical spinal cord contusion injury model in rats and its histologic characterization

目的通过构建大鼠颈脊髓半侧挫伤动物模型,探究颈脊髓不同损伤程度的大鼠行为学和脊髓的组织学改变。方法选取80例成年雄性SD大鼠,按挫伤深度分为中度挫伤组(1. 2 mm) 30例和重度挫伤组(2. 0 mm) 30例,并设立假手术组20例,麻醉状态下对中、重度模型组大鼠C5脊髓左侧挫伤,根据挫伤位移的不同,分为1. 2 mm和2. 0 mm组,假手术组仅暴露C5脊髓。不同时间点对各组大鼠前肢运动功能进行评分。挫伤8周后,对模型鼠脊髓横断面进行组织学分析,并计算各组大鼠灰、白质残存面积之间存在的差异。结果中度损伤组打击力和位移分别为(1. 03±0. 21) N和(1. 20±0. 02) mm,重度损伤组打击力和位移分别为(1. 72±0. 35) N和(2. 02±0. 03) mm,中度损伤组的打击力明显小于重度损伤组(P <0. 05)。中、重度模型组大鼠灰质和白质残存面积组间存在统计学差异(P <0. 05)。结论该研究按大鼠颈脊髓半侧挫伤深度不同成功构建了颈脊髓研究的动物模型,中、重度模型组的大鼠单侧前肢呈现不同程度的损伤,组间差异具有统计学意义。

Objectives:To establish unilateral cervical spinal cord contusion injury model in rats,and to evaluate the behavioral and histological changes with different degrees of cervical spinal cord injury.Methods:Eighty male adult Sprague-Dawley rats were divided into 1.2 mm group(n=30)defined as moderate injury group,2 mm group(n=30)defined as severe injury group and the control group(n=20).The sham group only exposed the spinal cord without contusion.The left spinal cord of C5 was exposed under anesthesia.The maximum impact force and the contusion energy were recorded at different time points.All outcome measures were estimated weekly prior to and up to 8 weeks following injury.The spared areas of gray and white matter at the epicenter were analyzed on cross-sections of spinal cord,and both groups had significant difference.Results:The peak force and actual contusion displacement were(1.03±0.21)N and(1.20±0.02)mm in the moderate group and(1.72±0.35)N and(2.02±0.03)mm in the severe group respectively.Significant difference was observed in the peak force and contusion energy between groups.There was significant difference in the spared areas of gray and white matter between the groups(P<0.05).Conclusion:This study successfully establishes a different degree of unilateral cervical spinal cord contusion model in rats,which shows persistent unilateral neurological dysfunction and structural destruction of the injured spinal cord and the motor impairment,and it can be used for basic research of spinal cord injury.