2型糖尿病性骨质疏松大鼠骨组织IGF-1表达变化

Expression of IGF-1 mRNA in bone tissues of type 2 diabetic osteoporosis rats

目的探讨骨骼组织中胰岛素样生长因子1(insulin-like growth factor-1,IGF-1)与2型糖尿病性骨质疏松发病的关系。方法高脂喂养雌性Wistar大鼠8周,腹腔注射链脲佐菌素,并实施双侧卵巢切除手术继续喂养12周,构建大鼠2型糖尿病性骨质疏松模型;测定大鼠体重、空腹血糖、胰岛素水平和骨密度,计算胰岛素敏感指数;收集大鼠骨骼组织,提取RNA,使用实时定量PCR法分析大鼠骨骼组织中IGF-1 mRNA水平。结果在大鼠实施卵巢切除手术12周后,正常去卵巢组体重略高于正常对照组,2型糖尿病组和2型糖尿病去卵巢组体重低于正常对照组和正常去卵巢组,2型糖尿病去卵巢组体重又高于2型糖尿病组(P<0.05);正常去卵巢组空腹血糖低于正常对照组,2型糖尿病组和2型糖尿病去卵巢组空腹血糖高于正常对照组和正常去卵巢组,2型糖尿病去卵巢组空腹血糖又高于2型糖尿病组(P<0.05);各组间空腹胰岛素水平呈逐渐升高,各组间胰岛素敏感指数呈逐渐降低(P<0.05);正常去卵巢组骨密度低于正常对照组,2型糖尿病组的骨密度低于正常对照组,高于正常去卵巢组,2型糖尿病去卵巢组骨密度又低于2型糖尿病组(P<0.05);各组间IGF mRNA相对水平呈逐渐降低(P<0.05)。结论大鼠骨组织中IGF-1 mRNA水平随骨密度减少而降低。

Objective To determine the relationship between insulin-like growth factor-1(IGF-1)mRNA levels of bone tissues and the pathogenesis of type 2 diabetic osteoporosis.Methods After fed with high fat diet for 8 weeks,rats was injected with streptozotocin intraperitoneally and had ovariectomy to establish type 2 diabetic osteoporosis rat mode.The body weight,fasting plasma glucose,insulin and bone mineral density were analyzed in type 2 diabetic osteoporosis rats.Real-time PCR was used to measure the expression of IGF-1 in bone tissue of type 2 diabetic osteoporosis rats.Results Twelve weeks after ovariectomy,body weight of normal ovariectomy(NOVX)group was slightly higher than that of normal control(NC)group.Body weight of diabetic control(DC)group and diabetic ovariectomy(DOVX)group was lower than that of NC group and NOVX group.And body weight of DOVX group was higher than that of DC group(P<0.05).The level of fasting blood glucose of NOVX group was lower than that of NC group.The levels of fasting blood glucose of DC group and DOVX group were higher than those of NC group and NOVX group.And the level of fasting blood glucose of DOVX group was higher than that of DC group(P<0.05).The levels of fasting insulin were increased gradually and insulin sensitivity was decreased gradually in all groups(P<0.05).Bone mineral density of NOVX group was lower than that of NC group.Bone mineral density of DC group was lower than that of NC group and was higher than that of NOVX group(P<0.05).The relative levels of IGF mRNA were decreased gradually among groups(P<0.05).Conclusion The level of IGF-1 mRNA in rat bone tissue decreased with the decrease of bone mineral density.