Therapeutic effects of globular adiponectin in diabetic rats with nonalcoholic fatty liver disease

AIM:To explore the therapeutic role of globular adiponectin(gAd)in high-fat diet/streptozotocin(STZ)-induced type 2 diabetic rats with nonalcoholic fatty liver disease(NAFLD).METHODS:Seven rats were fed a basic diet(normal control group;NC)during the experiment.Experimental rats(14 rats)were given a high-fat diet for 4 wk and were then injected with STZ to induce type 2 diabetes mellitus(T2DM)and NAFLD.Half of the T2DM/NAFLD rats were randomly injected intraperitoneally with gAd for 7 d(gAd-treated group),while the other 7 rats(T2DM/NAFLD group)received 0.9%saline.Plasma biochemical parameters and insulin concentrations were measured.Liver histopathology was examinedby hematoxylin-eosin staining.Insulin receptor expression in the liver was analyzed by immunohistochemical staining,Western blot and quantitative real-time reverse transcription polymerase chain reaction analysis.RESULTS:Compared to the control group,the T2DM/NAFLD group had increased levels of glucolipid and decreased levels of insulin.Plasma glucose and lipid levels were decreased in the gAd-treated group,while serum insulin levels increased.The expression of insulin receptor in the T2DM/NAFLD group increased compared with the NC group,and gAd downregulated insulin receptor expression in the livers of T2DM/NAFLD rats.Steatosis of the liver was alleviated in the gAd-treated group compared to the T2DM/NAFLD group(NAS 1.39±0.51 vs 1.92±0.51,P<0.05).CONCLUSION:Globular adiponectin exerts beneficial effects in T2DM rats with NAFLD by promoting insulin secretion,mediating glucolipid metabolism,regulating insulin receptor expression and alleviating hepatic steatosis.