Effects of Soybean Peptide on Haemodynamics and Myocardial Autophagy Levels in Rats with Exhaustive Exercise

Objective:To observed the effects of soybean peptide(SP)on haemodynamic and myocardial autophagy levels in rats with exhaustive exercise(EE),its cardioprotective mechanism of inhibiting autophagy was explored. Methods:Fifty rats were divided into 5 groups,normal control group(distilled water by intragastric administration(ig)without compulsive exercise),exhaustive exercise model group,(distilled water by ig,forced swimming to exhaustive),and soybean with high,middle and low dose group(soybean peptide 500,250 and 125 mg/kg by ig,and forced swimming to exhaustive). The rats’ haemodynamic parameers(LVEDP,LV dp/dt max,LV dp/dt min,LVSP,MABP and HR)were measured. The histopathological changes of rats cardiac apex tissue were observed by HE stain. The expression levels of mRNA and protein of LC3,Beclin-1 and Atg7 in myocardial tissue were analyzed by RT-PCR and western blot methods. Results:Compared with the exhausted exercise model group,the LVEDP of the 500 mg/kg SP decreased in rats with exhaustive exercise,the LV dp/dt max,LV dp/dt min,LVSP and MABP increased,improved the hispathological changes of myocardial tissue in rats with exhaustive exercise,down-regulated the expression levels of mRNA and protein of LC3,Beclin-1 and Atg7 in myocardial tissue of rats with exhaustive exercise. Conclusion:Soybean peptide could ameliorate the cardiac function and hemodynamics in rats with exhaustive exercise,and its mechanism may be related to inhibition of autophagy.