Relationship between insulin resistance and triglyceride accumulation in non-adipose tissues in high-fat-fed SD rats

AIM: To explore the accumulation of triglyceride(TG)in liver,muscle and pancreas in high-fat-diet induced insulin resistance rat model and the relationship between the insulin resistance and the accumulation of TG in non-adipose tissues. METHODS: Twenty 9-week male SD rats were randomly divided into 2 groups and fed for 6 weeks with high-fat diets (high-fat group, n=10) and standard diets (control group, n=10). Blood was collected every 7 d for detecting free fatty acids (FFA),fasting insulin (FINS) and fasting plasma glucose(FPG). Insulin resistance was determined with Homa-model analysis(HOMA-IR).The accumulation of TG in liver, muscle and pancreas was investigated by oil red O staining and computer semi-quantitative analysis on the 6th week. RESULTS: In high-fat group as compared with control group, FFA (mmoL/L, 0.74±0.04 vs 0.62±0.05, P0.01) , FINS (mU/L, 31.96±2.58 vs 12.64±1.35, P0.01), FPG (mmoL/L, 5.32±0.55 vs 5.12±0.47, P0.01), HOMA-IR (7.57±1.11 vs 2.87±0.35, P0.01) were increased significantly . On the 6th week, the amount of TG accumulation in liver and muscle was significantly higher than that in pancreas. There was no significantly difference in the TG accumulation in pancreas between the high-fat group and the control group (P0.05), but significantly in the liver(99.5±4.7 vs 128.5±3.9, P0.01) and muscle (127.6±3.1 vs 134.7±2.9, P0.01). CONCLUSION: The high-fat-diet can induce insulin resistance in SD rats, which seems to be related to higher serum FFA and the accumulation of TG in liver and muscle.