【摘要】 本研究的目的是揭示运动训练改善心衰大鼠室旁核γ-氨基丁酸B型(GABAB)受体介导的交感传出抑制性作用的机制.以冠状动脉结扎法诱导大鼠心衰模型,并对心衰大鼠进行游泳训练.为检测室旁核内γ-氨基丁酸(GABA)的作用,向所有实验组大鼠室旁核内微量注射GABAB受体的阻断剂CGP35348,该药剂量依赖性的使肾交感神经活放电动、动脉血压和心率增加,但与假手术组相比较,心衰组大鼠的以上三个指标的增加发生钝化.然而,运动训练可明显改善这一钝化现象.RT-PCR结果显示,与安静对照心衰组大鼠相比,运动训练心衰组大鼠室旁核内GABAB受体mRNA表达量明显增加,结果提示运动训练改善心衰大鼠室旁核GABAB受体介导的交感传出抑制性作用可能与室旁核内GABAB受体的上调有关.更多还原

【Abstract】 The goal of this study was to disclose the mechanism of exercise(ExT) in improving GABAB receptor mediated sympathetic outflow within the paraventricular nucleus(PVN) in rats with heart failure.Heart failure(HF) animal model was induced by coronary artery ligation and swimming was conducted.To examine the functional role of γ-aminobutyric acid(GABA) within the PVN,an antagonist of GABAB receptor,CGP35348,was microinjected into the PVN.Dose-dependent increases in RSNA,arterial blood pressure(BP),and heart rate(HR) were produced in all rats.There was a blunted increase in these parameters in HF rats compared with the sham-operated rats.However,ExT significantly improved the blunted phemomenon in HF rats.The results of RT-PCR show that GABAB receptor mRNA expression levels in the PVN were also significantly increased in HF-ExT rats compared with HF-sedentary rats.Our results indicate that ExT improves GABAB receptor mediated sympathetic outflow within the paraventricular nucleus in rats with heart failure and the mechanism may be involved in the upregulation of GABAB receptor in PVN.更多还原