中文摘要：

目的：观察有氧运动对自发性高血压大鼠（SHR）离体胸主动脉反应性及电压门控钾通道（Kv）蛋白表达的影响，探讨运动降低血压的血管平滑肌钾通道机制。方法：24只雄性SHR随机平均分为安静组（SHR—SED）和运动组（SHR—EX），另选用同龄雄性WKY大鼠作为正常血压对照组。SHR—EX组进行8周有氧运动，坡度0°，20m/min，60min／d，5d／周。8周后，检验离体胸主动脉对去甲肾上腺素（NE）、4-氨基吡啶（4-AP）的反应性。另用免疫组化DAB法和Western blot法测定胸主动脉平滑肌Kv1．2和Kv1．5的表达情况。结果：1）SHR—EX组血压显著低于SHR-SED组1）SHR-EX组离体胸主动脉对NE的敏感性小于SHR-SED组。2）4-AP诱发的血管收缩反应在SHE—EX组中显著大于SHR．SED组。3）SHR—EX组Kv1．2和Kv1．5表达均显著高于SHE—SED组，有氧运动显著抑制Kv1．2和Kv1．5表达的下调。结论：长期规律的有氧运动训练可降低SHR的收缩压，减弱胸主动脉对缩血管物质的反应性，其重要机制之一为有氧运动显著抑制高血压诱导的平滑肌细胞Kv通道蛋白表达下调。

英文摘要：

Objectives： This paper aims to investigate the effect of aerobic exercise on the vascular reactivity of thoracic aorta and voltage-gated potassium channel （Kv ） expression in spontaneously hypertensive rats （SHR） ,and to explore the possible potassium channel mechanisms in vascular smooth muscle cells （VSMCs） underlying the beneficial effects of exercise training on hypertension. Methods ： Twenty-four male SHRs were randomly assigned to a sedentary group （SHR-SED） and an exercise training group （SHR-EX）. SHR-EX underwent treadmill training at 20 m/min for 60 min/d ,5 d/wk ,for 8 weeks. Age-matched male WKY rats were used as control. Vascular contractility of thoracic aortas in response to norepinephrine （NE） and 4 -aminopyridine （4 -AP, a selective Kv channel blocker） was measured. Immunohistochemistry and western blotting were performed to examine the expressions of Kv 1.2 and Kv 1.5. Results ： The NE sensitivity of aorta rings was SHR-SED 〉 SHR-EX 〉 WKY. 4 - AP induced a significant increase of vessel tension in all three groups. The maximal tension increased by 4 - AP was SHR-SED 〈 SHR-EX 〈 WKY. Immunohistochemistry and western blotting showed that Kv 1.2 and Kv 1.5 expressions were significantly decreased in hypertension and exercise training attenuated this reduction. Conclusion： Regular aerobic exercise training attenuates SHR-related down-regulation of Kvl. 2 and Kv1. 5 expression in VSMCs,which may be an important mechanism underlying the beneficial effects of exercise training on hypertension and arterial function.