Exercise training prevents the exaggerated exercise pressor reflex in rats with chronic heart failure.
Exercise training prevents the exaggerated exercise pressor reflex in rats with chronic heart failure.
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DOI：
10.1152/japplphysiol.01273.2009
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发表时间：
2010-05
影响因子：
3.3
通讯作者：
Han-Jun Wang;Yanxia Pan;Weizhong Wang;Lie Gao;M. Zimmerman;I. Zucker;Wen Wang
中科院分区：
文献类型：
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作者：
Han-Jun Wang;Yanxia Pan;Weizhong Wang;Lie Gao;M. Zimmerman;I. Zucker;Wen Wang
在慢性心力衰竭（CHF）状态下会发生过度的运动升压反射（EPR），这会导致运动不耐受和运动时过度的交感兴奋。运动训练（ExT）可改善CHF患者的异常心血管反射。ExT是否能使夸大的EPR函数正常化仍有待确定。本研究旨在探讨ExT对EPR和机械或代谢成分的这种反射在假手术和CHF大鼠的影响。电刺激L4/L5前根引起的静态收缩可激活EPR。被动牵拉和后肢动脉注射辣椒素（0.1和1微克/公斤，0.2毫升），分别激活与机械反射和代谢反射的传入纤维。在假手术+久坐（Sed）、假手术+ExT、CHF+Sed和CHF+ExT大鼠中比较这些反射激活期间的心率、血压和交感神经兴奋反应。与sham+Sed大鼠相比，CHF+Sed大鼠表现出夸张的心率和升压和交感神经兴奋反应，无论是静态收缩或被动拉伸，而心血管反应注射辣椒素钝化。8 ~ 10周的ExT使由静态收缩或被动牵拉引起的过度反应正常化，并部分改善了CHF大鼠动脉内辣椒素引起的迟钝反应。ExT对假手术大鼠的EPR和机械反射、代谢反射功能无明显影响。这些研究结果表明，在CHF状态下激活EPR后，ExT在最大限度地降低动脉压和交感神经流出方面具有潜在的治疗作用。
An exaggerated exercise pressor reflex (EPR) occurs in the chronic heart failure (CHF) state, which contributes to exercise intolerance and excessive sympathoexcitation during exercise. Exercise training (ExT) improves abnormal cardiovascular reflexes in CHF. Whether ExT can normalize the exaggerated EPR function remains to be determined. This study was designed to investigate the effects of ExT on the EPR and on the mechanical or metabolic components of this reflex in sham-operated and CHF rats. The EPR was activated by static contraction induced by electrical stimulation of L4/L5 ventral roots. The afferent fibers associated with the mechanoreflex and metaboreflex were activated by passive stretch and hindlimb arterial injection of capsaicin (0.1 and 1 microg/kg, 0.2 ml), respectively. Heart rate, blood pressure, and sympathoexcitatory responses during the activation of these reflexes were compared in sham+sedentary (Sed), sham+ExT, CHF+Sed, and CHF+ExT rats. Compared with sham+Sed rats, CHF+Sed rats exhibited exaggerated heart rate and pressor and sympathoexcitatory responses to either static contraction or passive stretch, whereas the cardiovascular responses to injection of capsaicin were blunted. Eight to ten weeks of ExT normalized the exaggerated responses induced by static contraction or passive stretch and partially improved the blunted responses due to intra-arterial capsaicin in CHF rats. ExT had no significant effect on the EPR and mechanoreflex and metaboreflex functions in sham rats. These findings suggest a potential therapeutic role for ExT in minimizing arterial pressure and sympathetic outflow following activation of the EPR in the CHF state.