孕酮对大鼠脊髓损伤后早期细胞凋亡的影响

目的:探讨孕酮对大鼠脊髓损伤后早期细胞凋亡的影响。方法:60只雄性SD大鼠随机分成假手术组、损伤组、孕酮组,采用改良的Allen’s撞击法制作脊髓损伤模型。孕酮组在造模成功后1、6、24、487、2 h腹腔注射16 mg/kg孕酮。术后6、24、48、75 h取材,采用HE染色观察脊髓形态学的变化,免疫组织化学法检测Caspase-3的表达,原位末端标记法(TUNEL染色)检测细胞凋亡。结果:假手术组大鼠脊髓形态正常,偶见凋亡细胞及Caspase-3阳性细胞;与损伤组相比,孕酮组术后各时间点的凋亡指数下降,Caspase-3阳性细胞数显著减少,差异有统计学意义。结论:抑制脊髓损伤后的细胞凋亡可能是孕酮的神经保护作用机制之一。

Effects of Progesterone on Cell Apoptosis in Early Spinal Cord Injury Rats

Objective:To investigate the effects of progesterone on cell apoptosis in early spinal cord injury(SCI) rats.Methods:Sixty male Sprague-Dawley rats were randomly divided into the sham-operation group,SCI group and progesterone treatment group.The SCI rat model was made according to the modified Allen's contusion method.Five injections of 16 mg/kg progesterone were given at1,6,24,48 and 72 h post-lesion by intraperitoneal injection.All the rats were sacrificed at 6,24,48 and 75 h respectively after SCI.The lesion area in the spinal cord was dissected for morphological study by HE staining.The expression of caspase-3 was detected with immunohistochemistry method.Cell apoptosis was examined by TUNEL staining.Results:The sham-operation group displayed the normal histology morphology and there were few tunnel-positive cells and caspase-3 positive cells.When compared with the injured group,the apoptotic index and the amount of caspase-3 positive cells of the progesterone group decreased significantly at 6,24,48 and 75 h respectively after SCI.Conclusion:Inhibition of cell apoptosis after the spinal cord injury in rats may be one of the neuroprotective mechanisms of progesterone.