星形胶质细胞划痕或缺血损伤后亚低温保护作用的研究

Protective effect of mild hypothermia on astrocytes with traumatic or ischemic injury

目的探讨亚低温对大鼠星形胶质细胞不同类型损伤的保护作用。方法体外原代培养SD大鼠星形胶质细胞,分别以划痕和厌氧培养代表机械损伤和缺血缺氧损伤类型。实验分为对照组(C组)、单纯缺氧组(H组)、缺氧+白细胞组(H+W组)、划痕组(S组)和划痕+白细胞组(S+W组)。将各组细胞置入37、34、32℃CO2孵箱中培养24h,应用速率法和LIVE/DEAD染色分别检测和观察各组细胞在不同温度下的乳酸脱氢酶(LDH)释放率和细胞形态学变化。结果与37℃相比,H组乳酸脱氢酶(LDH)释放率从(33.02±3.58)%分别下降为34℃时的(11.48±1.53)%和32℃时的(3.79±0.45)%(P<0.05);H+W组LDH释放率从(51.14±2.17)%分别下降为34℃时的(19.53±4.37)%和32℃时的(16.68±1.47)%(P<0.05),而S组与S+WBC组LDH释放率在34℃和32℃时与37℃相比均无显著差异(P>0.05)。结论亚低温可明显减轻缺血缺氧对星形胶质细胞的损伤,但对单纯划痕损伤的保护作用不显著。

Objective To investigate the protective effect of mild hypothermia on rat astrocytes with traumatic or ischemic injury. Methods Rat astrocytes in primary culture were subjected to scratching or hypoxic injury and exposed to normothermia （37 ℃） or hypothermia （34 or 32 ℃） for 24 h. The morphology of the astrocytes was evaluated by live/dead staining, and the cell injury was measured by lactate dehydrogenase （LDH） release assay. Results As the temperature reduced the LDH release rate from the cells in hypoxic group decreased significantly, to （11.48±1.53）% at 34 ℃ and （3.79±0.45）% at 32 ℃ as compared to that in normothermia [（33.02±3.58）%] in the absence of rat white blood cells （WBC） （P0.001）. LDH release rate of the hypoxic cells further decreased in the presence of rat WBC to （51.14±2.17 ）% at 37 ℃, （19.53±4.37）% at 34 ℃ and （16.68± 1.47）% at 32 ℃ （P0.001）. In the scratched cells, with or without WBC, LDH release rate showed no significant variation between the 3 temperatures （P0.05）. Conclusion Mild hypothermia offers obvious protective effects on rat astrocytes against ischemic damage but not against mechanical injury.