Effects of Varied-Intensity of Exercise on Ca_V1.2 Channel Remodeling in Mesenteric Artery from Spontaneously Hypertensive Rats

Objective:Exercise can be considered as a simple and effective non-drug treatment of hypertension.Choosing appropriate intensity and volume is supposed to be of great importance.L-type Ca2+(CaV1.2)channels on the plasma membrane of vascular smooth muscle cells play a key role in modulating vascular tone.CaV1.2channels upregulation is an ionic feature of hypertension.This study aimed to explore the effects of different intensity of exercise on CaV1.2channel remodeling of mesenteric artery(MA)from SHR.Methods:Twelve-week-old male SHR rats were randomly divided into SHR sedentary group(SHR-SED,n=18),SHR Moderate-(SHR-M,n=18,18~20 m/min)and high-intensity(SHR-H,n=18,26~28 m/min)of exercise training exercise group.Eighteen age-matched WKY rats were used as normotensive control.Mesenteric arterial mechanical and functional properties were evaluated.Results:Moderate-intensity of exercise training induced lower systolic blood pressure and heart rate than those of SHR-SED.Moderate-intensity of exercise training significantly suppressed tissue sensitivity to nifedipine,CaV1.2channel currents density,and CaV1.2-α1Csubunit protein expression in MAs.However,high-intensity of exercise aggravated all of these hypertension-associated functional and molecular alterations of CaV1.2channel.Conclusion:Remodeling of MAs contributes to the development and complications of hypertension.The moderate-intensity exercise can effectively reverse the remodeling of CaV1.2channels in mesenteric artery,which has a positive effect on improving vascular function.High-intensity exercise would exaggerate the adverse remodeling of CaV1.2channel which impairs vascular function further.