1型糖尿病大鼠肾小管间质纤维化的病理改变

Pathological changes of renal tubulointerstitial fibrosis in type 1 diabetes mellitus rats

目的探讨不同病程1型糖尿病大鼠模型肾小管间质的病理变化。方法腹腔注射链尿佐菌素(STZ,65 mg/kg)建立SD大鼠1型糖尿病模型,注药后7 d造模成功后分别于4周、12周和24周Masson染色观察血管周围胶原面积(PVCA)、肾小管间质病变评分(TILS),用免疫组织化学法对肾脏胶原蛋白(collagenⅠ、collagenⅢ)在肾脏的分布及表达进行半定量分析,肾脏光镜与电镜观察,并与同龄正常大鼠进行比较。结果与正常对照组比较,糖尿病组肾脏纤维化指标PVCA、TILS、collagenⅠ、collagenⅢ的表达均明显增高(P<0.05)。电镜发现糖尿病组肾小球毛细血管基底膜弥漫性增厚,近曲小管上皮细胞空泡化。结论早期糖尿病大鼠模型已出现肾小管间质纤维化改变,损伤的肾小管间质有助于早期判断糖尿病肾病肾脏损伤程度。

Objective To investigate the renal tubulointerstitial pathomorphology at different stages of type 1 diabetes mellitus （DM） rats. Methods The diabetes mellitus rat model was induced by an intraperitoneal injection of streptozotocin （STZ,Sigma） at a dose of 65 mg/kg body weight. At week 4,12 and 24 after DM was successfully induced, the perivascular collagen area （PVCA） and the tubu- lointerstitial lesion score （TILS） were observed by Masson＇ s trichrome staining. The expression of typeⅠ and Ⅲ collagens was evaluated by qualitative and semiquantitative immunohistochemical staining. Renal pathomorphology changes were observed under a light microscope and a transmission electron microscope. The age-matched normal rats served as control group. Results Compared with control rats, PVCA, TILS , collagen Ⅰ and collagen Ⅲ in kidney were increased in diabetic rats（P 〈 0.05 ）. Diffuse thickening of glomerular capillary basement membrane and epithelial cell vacuole of proximal convoluted tubular in diabetic rats were observed under an electron microscope. Conclusion The early diabetes mellitus rat shows pathomorphology changes of renal tubulointerstitial fibro- sis. The damage of renal tubule is helpful to early diagnose the degree of kidney damage.