中文摘要：

目的：研究不同运动强度对自发性高血压大鼠（SHR）的肠系膜动脉的大电导钙激活钾通道（MaxiK）功能重塑的影响。方法：54只3月龄雄性SHR随机分为3组：低强度有氧运动组（SHR-L,n=18）,中强度有氧运动组（SHR-M,n=18）和安静组（SHR,n=18）。18只同龄雄性WKY作为空白对照组（WKY,n=18）,运动组完成8周的运动训练。运动方案：坡度0°,60 min/d,5 d/w,SHR-L,14 m/min,40%49%VO2max;SHR-M,20 m/min,55%65% VO2max。8周运动结束后急性酶分离肠系膜动脉平滑肌细胞（VSMCs）。记录不同运动强度对肠系膜动脉MaxiK通道电流及通道蛋白亚基表达的影响。结果：1.运动训练前,与WKY组相比,SHR安静组体重（BW）无显著性差异（P〉0.05）,但心率（HR）和平均动脉压（MAP）均显著升高（P〈0.05）,经过8周的运动训练后,SHR-L组和SHR-M组的BW、HR和MAP都较SHR安静组明显降低（P〈0.05）,且与SHR-L组相比,SHRM组MAP降低程度更为显著（P〈0.05）;2.与WKY组相比,SHR安静组MaxiK通道NPo值显著升高（P〈0.05）;与SHR安静组相比,经过8周运动训练后,SHR-L和SHR-M组MaxiK通道NPo值明显降低（P〈0.05）,且SHR-M组比SHR-L组的降低作用更为显著（P〈0.05）;3.与WKY组相比,SHR安静组β1亚基和α亚基蛋白表达水平均升高,但β1亚基升高程度较α亚基更明显,即β1/α比值显著升高（P〈0.05）,与SHR安静组相比,8周运动训练可显著降低β1/α比值（P〈0.05）,而且SHR-M组比SHR-L组的改善作用更为显著（P〈0.05）。结论：有氧运动可以纠正高血压相关的肠系膜血管平滑肌MaxiK通道病理性重塑,并由此改善由高血压引起的该通道的病理改变,延缓并改善高血压症状,在低强度有氧运动到中强度有氧运动范围内,运动对高血压症状的改善作用具有运动强度的依赖性。

英文摘要：

Objective：The purpose of this study is to determine the effects of exercise intensity on hypertension-associated changes in large-conductance Ca2＋-activated K＋（MaxiK） channels in mesenteric arteries from spontaneously hypertensive rats（SHR）.Methods：Male SHR（n=54） were randomly assigned to three groups：a low-intensity aerobic exercise group（SHR-L）,a moderate-intensity aerobic exercise group（SHR-M）,and a sedentary group（SHR）.Age-matched male WKY（n=18）were used as normotensive controls.Aerobic exercise groups completed an 8-week exercise training.After 8 weeks of aerobic exercise,the segment of mesenteric arteries was carefully dissected free,and separated into smooth muscle cells by one step digestion.Results：SHR mesenteric arteries MaxiK channel subunit protein expression,β1/α ratio,whole cell current density and single-channel open probability was also increased compared with WKY（P〈0.05）.Aerobic exercise reduced systemic blood pressure and normalized hypertension-associated mesenteric arteries（P〈0.05）.MaxiK alterations to normotensive control levels in the SHR（P〈0.05）.These effects were more pronounced in the moderate-intensity group than in the low-intensity group.Conclusions：Aerobic exercise training can effectively correct the pathological adaptation of mesenteric arteries MaxiK channels in spontaneously hypertensive rats by downregulation of β1/α to restore the vascular function in mesenteric arteries,which are intensity/volume dependent.