骨组织中IRS-1水平与2型糖尿病性骨质疏松症的关系

Correlation between the expression levels of IGF-1 in bone tissues and type 2 diabetic osteoporosis in rats

目的探讨骨骼组织中IRS-1表达水平同2型糖尿病性骨质疏松症的关系。方法清洁级健康雌性Wistar大鼠为研究对象,适应性喂养1周后,随机分为正常对照组(NC组)、正常去卵巢组(NOVX组)、2型糖尿病对照组(DC组)和2型糖尿病去卵巢组(DOVX组),每组5只。以高脂饲料喂养8周后,腹腔注射链脲佐菌素,并实施双侧卵巢切除手术,建立2型糖尿病性骨质疏松症模型;卵巢切除手术第12周时,检测大鼠体重、空腹血糖和胰岛素、骨密度;计算大鼠胰岛素敏感指数;麻醉处死后分离股骨和肱骨,提取总RNA并使用实时定量PCR法检测IRS-1mRNA水平。结果除卵巢后第12周,与NC组比较,DC组和DOVX组大鼠空腹血糖和胰岛素水平明显升高(P<0.05);胰岛素敏感指数和骨密度降低(P<0.05);与NC组比较,NOVX组和DOVX组大鼠骨骼织中IRS-1表达降低(P<0.05),其中DOVX组大鼠骨骼组织中IRS-1表达最低。结论大鼠骨骼组织中IRS-1mRNA水平同骨密度呈正相关,同2型糖尿病性骨质疏松发病呈负相关。

Objective To investigate the correlation between the expression levels of IGF-1 in bone tissues and type 2 diabetic osteoporosis in rats.Methods The healthy female Wistar rats(3 month age) were fed with high fat diet for 1 week,then were divided into control group,ovary excision group(NOVX group),type 2 diabetes mellitus group(DC group) and DOVX group,with 5 rats in each group.After 8-week feed with high fat diet,the rat models with type 2 diabetic osteoporosis were established by intraperitoneal injection with streptozotocin,followed by ovariectomy.At 12 weels after ovariectomy,the body weight,fasting blood glucose and insulin and bone mineral density were measured.After the rats were sacrificed,the bone tissues of rats were collected and total RNA was extracted,then the levels of IRS-1 mRNA in bone tissues were detected by Real-time PCR.Results As compared with those in control group,at 12 weeks after ovariectomy,the levels of fasting blood glucose and insulin in DC group and DOVX group were significantly increased(P<0.05),however,the levels of insulin sensitivity index and bone mineral density were significantly decreased(P<0.05).As compared with those in control group,the expression levels of IRS-1 mRNA in NOVX group and DOVX group were significantly decreased(P<0.05),moreover,which in NOVX group were the lowest.Conclusion The expression levels of IRS-1 in bone tissues of rats are negatively correlated with the pathogenesis of type 2 diabetic osteoporosis.