The Effect of 4 Weeks of Aerobic Exercise on Serum and Liver Levels of Neuregulin-4 in Diabetic Rats

Diabetes is associated with increased lipogenesis and expression of lipogenic genes in the liver, and neuregulin-4 activity is associated with inhibition of liver lipogenesis. The aim of this study was to investigate the effect of 4 weeks of aerobic exercise on changes of serum and liver levels of neuregulin-4and lipid profile in diabetic rats. 32 male adult rats were randomly divided into healthy control, control diabetic, exercise and exercise diabetic groups (each group 8 rats). Diabetes was induced by intraperitoneal injection of streptozotocin solution (55 mg/kg). The exercise was performed for 4 weeks, 5 sessions per week, at speeds of 15 to 18 m/min. and for 25 to 44 minutes. 48 hours after the last exercise session, blood samples were collected and liver tissue was removed and Neuregulin-4 levels were measured. The results showed no difference in serum and liver levels of neuregulin-4 between diabetic and healthy groups (P>0.05). Serum levels of cholesterol and HDL were not significantly different among the above groups (P>0.05). Triglyceride and LDL were significantly higher among these groups (P<0.05). 4 weeks of aerobic exercise did not affect serum and liver levels of neuregulin-4 in diabetic and healthy rats (P>0.05). Also, 4 weeks of aerobic exercise did not affect serum levels of cholesterol, triglyceride, HDL and LDL in healthy rats (P>0.05). Exercise in diabetic rats significantly decreased serum levels of cholesterol and triglyceride (P<0.05) but it did not make any significant differences in HDL and LDL (P>0.05). Although the levels of lipid profile changed significantly,  4 weeks of aerobic exercise probably cannot stimulate increases of neuregulin-4 in serum and liver tissue.