The Study Of Ghrelin And Visfatin Levels In Fasting Serum And Tissue And Their Correlations To Insulin Sensitivity In Rats With Type 2 Diabetes Mellitus

Objective: To measure levels of ghrelin and visfatin of fasting serum and tissue in rats with type 2 diabetes mellitus (T2DM) , obese rats and normal rat , to study their correlations to insulin sensitivity and type 2 diabetes mellitus.Methods: (1)Use high-sucrose and high-fat diet +STZ inducing wister rats, develop rats model with type 2 diabetes mellitus (T2DM);use only high-sucrose and high-fat diet develop obese rats model. (2)Use enzyme-linked immunoassay (EIA) to measure fasting serum ghrelin and visfatin in 18 type 2 diabetes rats, 15 obese rats and 10 normal rat. The body weight , body length and viscus fat weight were recorded, and calculate the lee index. Fasting blood glucose (FBG), triglyceride (TG), total cholesterol(TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), fasting serum insulin (FINS) were measured in all of the subjects, Use Bennett Index to estimate insulin sensitivity. (3) Use immunohistochemistry to measure ghrelin expressive level in stomach and visfatin in viscus fat tissue.Results: (1)Rats Use high-sucrose and high-fat diet (12 weeks)+STZ (35mg/kg) inducing have higher food-intake, drinking , urine volume, body weight, lee index, FBG, FINS than that of the control, and have lower insulin sensitivity than that of the control.(2) The fasting serum ghrelin was significantly lower in the diabetes rats ( 18.26±6.42pg/ml) and obese rats (15.57±5.23pg/ml) than that of the control (31.73±7.18pg/ml) (p<0.01).(3) The fasting serum ghrelin was significantly higher in the diabetes rats (26.38±12.74ng/ml) and obese rats (35.42±15.76ng/ml) than that of the control(p<0.05).(4) The fasting serum ghrelin of the diabetes rats was negatively correlated with lee index (r=-0.673, p<0.001), viscus fat weight ( r=-0.415, p=0.004), FBG(r=-0.228, p=0.02), FINS(r=-0.427, p=0.004), and it was positively correlated with ISI (r=0.329, p=0.005), HDL-c(r=0.354,p=0.005). The level of ghrelin in obese rats was negatively correlated with lee index (r=-0.846, p<0.001), viscus fat weight ( r=-0.362, p=0.009), FINS(r=-0.312, p=0.07), and it was positively correlated with ISI (r=0.376, p=0.006), HDL-c(r=0.298,p=0.043). The level of ghrelin in control rats was negatively correlated with lee index (r=-0.425, p=0.003), viscus fat weight (r=-0.265, p=0.038).(5) The fasting serum visfatin of the diabetes rats was positively correlated with viscus fat weight ( r=0.415, p<0.001), FBG(r=0.259, p=<0.035), and it was negatively correlated with HDL-c(r=-0.285,p=0.031). The level of ghrelin in obese rats was positively correlated with lee index (r=0.328, p=0.010), viscus fat weight ( r=0.498, p<0.001). The level of ghrelin in control rats was positively correlated with viscus fat weight ( r=0.456, p=0.003), TG(r=0.317, p=0.038).(6) The fasting serum ghrelin and visfatin level was not correlation.(7)After multiple regression analysis, the lee index seemed to be the best variable in predicting diabetes rats and obese rats ghrelin levels(r=-0.673, p<0.001; r=-0.846, p<0.001) ; the viscus fat weight seemed to be the best variable in predicting diabetes rats and obese rats visfatin levels(r=0.415, p<0.001; r=0.498, p<0.001).(8)The ghrelin expressive level in stomach of diabetes rats and obese rats was significantly lower than that of the control; the visfatin expressive level in viscus fat tissue of diabetes rats and obese rats was significantly higher than that of the control, and the ghrelin and visfatin expressive level in tissue was positively correlated with fasting serum level.Conclusion:The fasting serum ghrelin and expressive level in stomach was reduced in the diabetes and obese, and it was significantly associated with ISI. The fasting serum visfatin and expressive level in viscus fat tissue was advanced in the diabetes and obese, and it was not associated with ISI. The lee index is the determinative factor in serum ghrelin level while the viscus fat weight is the determinative factor in serum visfatin level in T2DM . Ghrelin and visfatin effect insulin sensitivity via obese.Stomach and viscus fat tissue is the mainly secrete position of ghrelin and visfatin respective.