ABSTRACT
Objective To observe the alteration of capillary density and apelin/APJ expression in soleus muscles of high-fat diet rats.Methods Male 5-week-old Sprague-Dawley rats were randomly divided into a control group and a high-fat diet group.After 12 weeks of high-fat diet,16 rats were se lected and randomly divided into a sedentary group and a treadmill running group.The exercise rats underwent 60-minute treadmill running at 26 m/min 5 days a week for 10 weeks.The body weight,body fat and blood lipid level were measured for all rats.The protein expression of Soleus CD31 and apelin was determined using immunohistochemical staining,soleus apelin content was determined using the radioimmunoassay,and the mRNA expression of apelin/APJ was detected using real-time PCR.Results Compared with the control group,significant increase was observed in the body weight,body fat and the level of total triglyceride,total cholesterol and low density lipoprotein cholesterin,but significant decrease was found in the high density lipoprotein cholesterin in the high-fat diet group.There were no significant differences in the capillary density and mRNA levels of apelin/APJ between the two groups.Compared with the sedentary high-fat diet group,significant improvement was observed in the body weight and blood lipid level of the treadmill running group.Moreover,significant increase was also observed in the capillary density,the expression of apelin/APJ mRNA,as well as that of apelin protein in the treadmill running group (P＜0.05).Conclusion The treadmill running can significantly increase capillary density of obese rats,as it may activate the expression of Apelin/APJ.