糖尿病大鼠终板微血管改变与髓核细胞凋亡的关系

目的:观察糖尿病大鼠椎间盘软骨终板微血管的改变和髓核细胞的凋亡情况,探讨糖尿病引起椎间盘退变的可能机制.方法:30只雄性SD大鼠随机分为实验组和对照组,每组15只.实验组采用腹腔单次注射链脲佐菌素溶液(STZ)50 mg/kg制成糖尿病模型,正常对照组仅注射等量的枸橼酸缓冲液.分别在建模成功后4,8,12周取腰椎间盘组织,HE染色观察椎间盘组织病理变化;用免疫组化的方法显示终板微血管,并进行计数;再用TUNEL法显示髓核组织细胞凋亡情况,测定凋亡率. 结果:在不同的阶段,实验组椎间盘的退变程度均较重,终板微血管计数均低于对照组,髓核细胞凋亡率也较高.两组终板微血管计数与髓核细胞凋亡率之间存在着负相关关系(对照组r=-0.953,实验组r＝-0.936,均为P<0.05).结论:与对照组相比,实验组终板微血管计数与髓核盘细胞凋亡率均具有显著性差异,糖尿病所伴发的终板微血管改变可能是导致椎间盘细胞凋亡的因素之一.

Relationship Between Pathologic Changes of Endplate Microvessels and Apoptosis of Nucleus Pulposus in the Intervertebral Disc of Diabetic Rats

Objective: To examine the microvessel pathologic changes of the endplate and the apoptosis of nucleus pulposus in the intervertebral disc of diabetic rats and to explore the possible mechanism of diabetes mellitus(DM) induced degeneration of intervertebral discs.Methods: Thirty male Sprague-Dawley rats were randomly divided into streptozotocin(STZ)-induced DM group and control group.The rats were killed 4,8 and 12 weeks later and lumbar discs were obtained.The histological changes were observed by hematoxylin and eosin(HE) staining.The endplate microvessel and nucleus pulposus apoptosis were measured by immunohistochemistry.Results: The numbers of microvessels and the apoptosis indices of nucleus pulposus in the endplate were significantly different between the two groups(both P<0.05).There was a negative correlation between the microvessel numbers of endplates and the nucleus pulposus cellular apoptosis index(r=0.953 in control group,r=-0.936 in DM group,both P<0.05).Conclusion: The cellular apoptosis index of the nucleus pulposus is increased significantly in the DM rats.The pathologic changes of microvessels in the endplates may be related to the apoptosis of the nucleus pulposus in the intervertebral disc in the diabetic rats.