Effects of insulin treatment on content of intramyocellular triglyceride and expression of CPTI-β gene in skeletal muscle of diabetic mellitus rats

AIM: To study the effect of insulin administration on the content of triglyceride and the expression of carnitine palmitoyl transferase I-β (CPTI-β) gene in skeletal muscle of diabetic mellitus(DM) rats.METHEDS: Wistar rats were randomly divided into normal control group(NC,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 glucose(FPG),insulin(FPI),free fatty acids(FFAs),triglyceride(TG) and the TGm(intramyocellular triglyceride)and the expression of CPTI-β gene in skeletal muscle were measured.HOMA2-IR was computed on the basis of FPI and FPG.RESULTES: Compared with NC group,HOMA2IR,TG and FFAs levels in the plasma and TGm contents of DH group were significantly higher(P(0.01)),and the expression of CPTI-β gene was decreased(P(0.01)).Compared with DH group,insulin administration didn't normalize TG(P(0.05)),but FFAs were decreased(P(0.01)),and TGm were increased(P(0.01)),although it improved insulin sensitivity of DHI group(P(0.05)),and the expression of CPTI-β were increased(P(0.01)).CONCLUSION: TG is accumulated in the skeletal muscle of DM rats,and the expression of CPTI-β is decreased,too.Insulin administration is able to up-regulate CPTI-β transcription,although it can increase the content of TGm as well.This phenomenon suggests insulin can ameliorate triglyceride metabolize in the DM rats.