胰岛素治疗对高脂喂养的糖尿病大鼠胰腺内胰岛素含量及胰岛素基因表达变化的影响

目的观察胰岛素治疗对长期高脂喂养的糖尿病(DM)大鼠胰腺内胰岛素含量和胰岛素基因表达的影响。方法Wistar大鼠随机分为正常饮食对照组(NC,n=10),糖尿病正常饮食组(DN,n=10),糖尿病高脂饮食组(DH,n=10)及糖尿病高脂饮食胰岛素治疗组(DHI,n=10)。测定空腹血浆游离脂肪酸(FFA)、甘油三酯(TG)和空腹葡萄糖(FBG)及口服葡萄糖负荷后2h血糖。留取胰腺标本分别测定胰腺内TG、FFA、胰岛素含量以及胰岛素基因表达水平。结果与NC组相比,DN组血浆及胰腺内TG和FFA含量明显增多(P<0·05~P<0·01),而胰岛素基因表达水平和胰岛素含量则明显降低(P<0·01、P<0·01);在两个糖尿病组之间,上述指标亦存在着差异,DH组血浆及胰腺内TG和FFA含量比DN组进一步增多(分别为P<0·01、P<0·01、P<0·01、P<0·05),且胰岛素基因表达水平和胰岛素含量进一步下降(P<0·05、P<0·01)。胰岛素治疗后,与DH组相比,血循环中的TG和FFA水平虽然没有改善(P>0·05),但胰腺内TG和FFA含量明显下降(P<0·01、P<0·01),同时胰岛素基因表达水平和胰岛素含量亦升高(P<0·01、P<0·01)。结论长期高脂喂养可损伤胰岛素的产生;胰岛素治疗对高脂饮食所致的上述影响有一定的改善作用。

Effects of the insulin therapy on the insulin content and the expression of insulin in pancreas of diabetic rats fed with prolonged high fat chow

Aim To investigate the effect of long term high fat diet on the insulin content and insulin gene expression in pancreas of diabetic mellitus (DM) rats,and the effect of the insulin therapy on above parameters. Method Wistar rats were randomly divided into normal control group (NC, n=10), diabetic with normal chow (DN,n=10), diabetes with high fat diet (DH ,n=10) and diabetes with high fat diet plus insulin therapy (DHI, n=10).The fasting plasma FFA,TG and the FFA,TG,insulin content and insulin gene expression in pancreas were measured. Results Compared with NC group, TG and FFA content in the blood and pancreas of DN group were significantly higher(P<0.05～P<0.01); and insulin gene expression、insulin content were decreased (P<0.01,P<0.01). Compared with DN group, TG and FFA in blood and pancreas of DH group were futherly increased (P<0.01,P<0.01;P<0.01,P<0.05), and insulin gene expression,insulin content were futherly decreased(P<0.05,P<0.01);After the treat- ment of insulin, compared with DH group, though plasma lipid did not been ameliorated obviously(P>0.05);TG and FFA content in pancreas were markedly reduced (P<0.01,P<0.01), furthermore, insulin gene expression and insulin content also increased simultaneously (P<0.01,P<0.01). Conclusion High fat diet can decrease the production of insulin. Insulin treatment could partly restore the impairment brought out by high fat diet.