中文摘要：

目的：观察有氧运动对自发性高血压大鼠（SHR）脑动脉平滑肌细胞自发瞬时外向电流（STOCs）的影响。方法：选用雄性SHR 24只,随机分为高血压安静组（SHR-SED组）和高血压运动组（SHR-EX组）,后者进行8周有氧跑台运动。另选用同龄雄性WKY大鼠12只作为正常血压对照组。8周后,取脑动脉,用酶消化法急性分离脑动脉平滑肌细胞。采用穿孔膜片钳实验记录各组大鼠脑动脉STOCs的变化。结果：（1）SHR-SED组基础收缩压显著高于WKY组,经过有氧运动训练后收缩压显著下降,但仍较WKY组高（P〈0.01）。（2）STOCs具有明显的电压依赖性,可被1 m M caffeine激活而被100 n M IBTX阻断;（3）在相同钳制电位下,自发性高血压可以显著增加脑动脉平滑肌细胞的STOCs的幅值,而频率无显著性改变。（4）有氧运动显著降低由高血压导致的STOCs幅值增高,而对频率无显著性影响。结论：自发性高血压大鼠脑动脉平滑肌细胞STOCs的幅值显著增大,与高血压背景下大电导钙激活钾通道（BKCa）功能的代偿性增强有关;长期有氧运动可以显著抑制此增强效应,阻止高血压背景下的BKCa通道的病理性改变。

英文摘要：

Objective The purpose of this study was to investigate the effects of aerobic exercise on the spontaneous transient outward currents（STOCs） in cerebral artery smooth muscle cells（CASMCs） of spontaneously hypertensive（SH） rats. Methods Twenty four male SH rats were randomly assigned to a sedentary control group（SH-SED,n =12） and an exercise training group（SH-EX,n =12）. Normotensive control group（WKY,n =12） consisted of age-matched male Wistar – Kyoto rats. The rats in SH-EX group underwent treadmill training for 8 weeks.After 8 weeks,the cerebral arteries of the rats were removed,and CASMCs were otained by enzymatic digestion. The change in STOCs was recorded by perforated patch-clamp.Results（1）The STOCs were voltage-dependent and could be activated by 1m M caffeine and blocked by100 n M IBTX.（2）Under the same holding potential,spontaneous hypertension increased the amplitude but the frequency of STOCs.（3）After aerobic exercise,the amplitude of STOCs decreased significantly and the frequency of STOCs remained unchanged.（4）STOCs were almost disappeared within 15 minutes after adding the blocking agent of large-conductance calcium-activated potassium channels. Conclusion The amplitude of STOCs in CASMCs of spontaneously hypertensive rats increased significantly,and probably was related to the compensatory enhancement of large-conductance calcium-activated potassium channels under the condition of hypertension,and long-term aerobic exercise could inhibit the increase in the amplitude of STOCs.