运动训练对高血压大鼠认知功能及脑内血管内皮一氧化氮合成酶的影响

目的:研究运动训练对高血压大鼠认知功能及脑内血管内皮一氧化氮合成酶(endothelial nitric oxide synthase,eNOS)的影响。方法:将30只3月龄自发性高血压易卒中(stroke-prone spontaneously hypertensive, SHRSP)大鼠随机分为对照组(SHRSP-Con)和训练组(SHRSP-PE),采用相同周龄的Wistar Kyoto(WKY)大鼠15只作为正常血压对照组(WKY-Con)。SHRSP-PE组给予持续4个月的跑笼训练;SHRSP-Con组和WKY-Con组不予任何针对性训练。各组大鼠在3及7月龄分别测血压、认知功能,观察皮质及海马的eNOS、β-secretase(BACE1)、β-amyloid(Aβ)的表达。结果:3月龄SHRSP大鼠的血压明显高于WKY大鼠,差异有显著性意义(P<0.05),各组大鼠认知功能无明显差异。7月龄SHRSP-Con组与WKY组比较,血压明显升高,认知功能减退,脑内eNOS表达减少、BACE1表达增加及Aβ沉积增加,差异有显著性意义(P<0.05)。与SHRSP-Con组相比,4个月的运动训练可以明显降低血压、改善认知功能且可以增加eNOS表达,减少BACE1和Aβ的表达,差异有显著性意义(P<0.05)。结论:运动训练能够改善慢性高血压大鼠的认知功能,其机制可能与其促进脑内eNOS表达,进而减少BACE1表达和Aβ沉积有关。

Effects of physical exercise on cognitive function and eNOS expression in stroke-prone spontaneously hypertensive rats

Objective: To investigate the effect of physical exercise on cognitive function, endothelial nitric oxide synthase (eNOS) and β-amyloid (Aβ) in cortex and hippocampus of stroke-prone spontaneously hypertensive (SHRSP) rats. Method: Experiments were carried out on 3-month-old male SHRSP rats (n=30) or age-matched normotensive Wistar Kyoto (WKY) rats (n=15). SHRSP rats were randomly divided into control (SHRSP-Con, n=15) and physical exercise (SHRSP-PE, n=15) groups. A 4-month exercise protocol with a wheel (21 cm in diameter, made in China) was implemented to rats in SHRSP-PE. Result: Compared with Wistar Kyoto (WKY) rats, the hypertensive challenge caused cognitive impairment, decreased eNOS levels and increased β-secretase (BACE1) and Aβ levels in the cortex and hippocampus. 4-month exercise lowered blood pressure (BP), promoted eNOS expression, ameliorated Alzheimer’s pathology, and improved cognitive function in SHRSP-PE rats. Conclusion: Long-term exercise initiated in rats at young age promoted eNOS expression and attenuated vascular-related Alzheimer's pathology in SHRSP-PE rats.