Effects of exercises on expressions of serum amyloid A protein and aorta resistin-like molecules α in insulin-resistant rats

Abstract

Objective To investigate the effects of exercises on expressions of serum amyloid A protein (SAA) and resistin-like molecules α(RELMα)in aorta of insulin-resistant(IR) rats induced by diets. Method Taking the completely randomized method, a total of 30 Wistar rats were divided into 3 groups: normal control group(n=10) fed with normal diet, IR and exercises groups with high sugar and high fat diet(10 rats in each group). Eight weeks later, the index of insulin resistance was assessed to confirm that models were successfully made.The three groups were continually fed with the same diet as before, while the exercise group was administered with swimming training for eight weeks in addition. At the end of sixteen weeks experiment, Rats' blood were sampled for measuring the levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), glucose (FBG), SAA, aorta RELMα mRNA and insulin (FINS) and the body weight(BW) were measured.The homeostasis model assessment index of IR(HOMA-IR)were calculated.Haematoxylin and eosin stain method was applied to observe morphology characteristics of aorta in groups. Difference of measurement data was compared with single factor analysis of variance. Results The levels of BW, FBG, FINS, HOMA-IR, TC, TG, LDL-C, SAA, RELMα mRNA in IR group were higher than those in control group(t=-20.666~-3.681, all P<0.05), and the number of foam cell increased well (t=-20.596, P<0.05), while the levels of HDL-C were lower(t=8.950, P<0.05). The endothelial in the IR group were in disorder, and neointimal hyperplasia was found. After the intervention of exercise, the levels of SAA, RELMα mRNA, BW, FBG, FINS, HOMA-IR, TC, TG, LDL-C excercises group were decreased than those in IR group(t=2.524~8.640, P<0.05), and the number of foam cell decreased well(t=11.520, P<0.05), while the levels of HDL-C were higher(t=-2.094, P=0.05). Conclusion RELMα, SAA is relate to IR, aortic inflammation closely.Exercise could inhibit the level of SAA, RELMα mRNA.It is important for improving IR and reducing aorta inflammation reaction. Key words: Insulin resistance; Resistin-like molecules α; Serum amyloid A protein; Exercise