亚低温对大鼠视网膜缺血再灌注损伤保护作用的电镜观察

目的 观察亚低温对缺血再灌注大鼠视网膜超微结构的影响，了解亚低温对视网膜缺血再灌注损伤是否有保护作用。方法 ２４只ＳＤ大鼠随机分正常组、缺血再灌注组和亚低温缺血再灌注组，每组８只。采用提高眼压法造成视网膜缺血后，恢复眼压形成血流再灌注。用透射电镜观察各组视网膜的超微结构。结果 缺血再灌注视网膜损伤主要表现在视细胞和节细胞。视网膜视细胞外节膜盘肿胀，排列紊乱，部分膜盘脱落，椭圆体内部分线粒体肿胀，节细胞的胞浆淡而空，节细胞水肿明显，多数线粒体肿胀、空泡化，滑面内质网扩张，部分粗面内质网扩张、脱粒；少数节细胞胞膜破裂、胞浆流失。亚低温缺血再灌注视网膜的视细胞外节膜盘略见疏松，椭圆体内线粒体正常；节细胞胞膜完整，包浆内可见肿胀线粒体，但肿胀较轻，其他细胞器未见明显改变。结论 亚低温可减轻缺血再灌注视网膜病变程度，对视

An Ultrastructural Study on Protection of Mild Hypothermia for Rat's Retina from Ischemia and Reperfusion Injury

Objective To know if mild hypothermia protects rat's retina from ischemia and reperfusion injury by observing the ultrastructure of retina. Methods 24 SD rats were randomly grouped into 3 groups:the control group,the ischemia and reperfusion group,and the ischemia and reperfusion group with mild hypothermia. In the experiment groups,intraocular pressure(IOP) was raised to occlude retinal and choroidal blood vessels to form retinal ischemia; afterwards IOP was lowered to normal level to allow reperfusion. The ultrastructure of retina of these 3 groups was observed. Results The pathologic changes of rat's retina after ischemia and reperfusion injury were mainly concentrated in visual cells and ganglion cells. The membrane discs of visual cells were swollen and disordered,mitochondria in the inner segment were partly swollen. Most ganglion cells were edematous,whose cytoplasm was thinly stained. The mitochondria were swollen and vacuolated,both smooth and rough endoplasmic reticula dilated; and some ganglion cells even ruptured. However,mild hypothermia could markedly abate the pathologic changes described above. Conclusion Mild hypothermia could protect the retina from ischemia and reperfusion injury.;