胰岛素样生长因子-1在代谢综合征大鼠和糖尿病大鼠膀胱中的表达变化

The expression change of insulin-like growth factor-1 in the bladders of metabolism syndrome and diabetic rats

目的 观察代谢综合征和2型糖尿病大鼠膀胱的镜下结构变化,探讨胰岛素样生长因子-1（IGF-1）在代谢综合征及2型糖尿病膀胱中的表达及意义.方法 将19只wistar大鼠随机分为3组,对照组5只,代谢综合征组7只（高脂饲料喂养建立代谢综合征模型）,2型糖尿病组7只（高脂饲料喂养＋腹腔注射链脲佐菌素建立2型糖尿病模型）.16周后取3组大鼠的膀胱组织,光镜下观察组织结构变化.应用免疫组织化学方法检测IGF-1在3组大鼠膀胱组织中的表达变化.结果 光镜下可见2型糖尿病大鼠膀胱黏膜下少许炎性细胞浸润,肌束排列松散,结构紊乱,肌束之间间隙增宽,肌束间血管扩张充血,逼尿肌细胞肥大明显,形态不一.代谢综合征组亦表现以上趋势,而正常组无以上表现.免疫组织化学显示,IGF-1蛋白在2型糖尿病组膀胱（0.212±0.032）中的表达同代谢综合征组（0.314±0.018）及正常组（0.336±0.011）两两比较明显下降（P＜0.05）,代谢综合征组相对于正常对照组差异无统计学意义（P＞0.05）.结论 代谢综合征能够使大鼠膀胱逼尿肌细胞发生改变,可能最终导致糖尿病膀胱病变,IGF-1在代谢综合征大鼠膀胱组织中表达无明显下降;2型糖尿病能够造成糖尿病膀胱病变,2型糖尿病状态下,IGF-1在膀胱组织中表达明显降低.

Objective To characterize the morphological changes of the bladders in metabolism syndrome and type 2 diabetes,and investigate the expression of insulin-like growth factor （IGF）-1 to clarify the role of IGF-1 in the progression of pathological bladder of metabolism syndrome and type 2 diabetes.Methods A total of 19 male Wistar rats were randomly divided into three groups：normal control group （NC,n =75）,metabolism syndrome group （Mets,n =77） and type 2 diabetes group （DM,n =7）.Metabolism syndrome models were established by feeding rats on high-fat food,while type 2 diabetes models were fed on high-fat food and intraperitoneal injection of streptozotocin （STZ）.At the end of 16th week,bladders were collected from the rats for hematoxylin-eosin （HE） staining and immunohistochemical staining.Results Morphological findings under light microscope：Inflammatory cell infiltration in the mucous membrane,disorderly muscle bundle in loose condition,the widened gap between the muscle bundle,engorged blood vessels in the muscle bundle and the hypertrophic musculus detrusor vesicae with disordered pattern and few light particls in the cytoplasm were observed in DM and Mets group.The levels of IGF-1 in the bladders of NC group,Mets group and DM group were 0.336 ±0.011,0.314 ±0.018,and 0.212 ± 0.032 respectively,with statistically significant difference between the DM group and the other two groups （P ＜ 0.05）,but there was no statistically significant difference between NC group and Mets group （P ＞ 0.05）.Conclusion Metabolism syndrome may lead to the pathological bladder which is manifested in diabetes,while the expression of IGF-1 in the bladders showed no substantial decrease.Type 2 diabetes can cause the diabetic cystopathy.IGF-1 expression is reduced in the bladders of rats with type 2 diabetes.