Thin-fiber mechanoreceptors reflexly increase renal sympathetic nerve activity during static contraction.
Thin-fiber mechanoreceptors reflexly increase renal sympathetic nerve activity during static contraction.
复制标题
细纤维机械感受器在静态收缩期间反射性地增加肾交感神经活动。
DOI：
10.1152/ajpheart.00771.2006
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Kaufman,MarcP
中科院分区：
文献类型：
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作者：
Kim,JongKyung;Hayes,ShawnG;Kindig,AngelaE;Kaufman,MarcP
运动时由交感神经流出引起的肾血管收缩有助于将血液从肾脏流向运动肌肉。在这方面，肾循环似乎特别重要，因为它接收很大一部分心输出量，据估计，在休息时，心输出量为20%。III组机械感受器在引起肾对静态收缩的反射性交感反应中的作用仍然是一个悬而未决的问题。为了阐明这一问题，我们记录了在未麻醉和氯氯糖麻醉的失脑猫静态收缩三头肌动脉供应中注射钆前后肾脏交感神经对静态收缩的反应。钆已被证明是薄纤维肌肉传入通道的选择性阻断剂，其中包括运动加压反射弧的传入臂。在失脑猫（n= 15）和氯蔗糖麻醉猫（n= 12）中，我们发现钆（10 mM; 1 ml）在静收缩60分钟后显著减弱肾交感神经和加压反应（60 s）；两种反应在120分钟潜伏期后恢复。我们认为，供给收缩肌的薄纤维机械感受器参与了运动加压反射引起的肾血管收缩。
The renal vasoconstriction induced by the sympathetic outflow during exercise serves to direct blood flow from the kidney toward the exercising muscles. The renal circulation seems to be particularly important in this regard, because it receives a substantial part of the cardiac output, which in resting humans has been estimated to be 20%. The role of group III mechanoreceptors in causing the reflex renal sympathetic response to static contraction remains an open question. To shed some light on this question, we recorded the renal sympathetic nerve responses to static contraction before and after injection of gadolinium into the arterial supply of the statically contracting triceps surae muscles of decerebrate unanesthetized and chloralose-anesthetized cats. Gadolinium has been shown to be a selective blocker of mechanogated channels in thin-fiber muscle afferents, which comprise the afferent arm of the exercise pressor reflex arc. In decerebrate (n= 15) and chloralose-anesthetized (n= 12) cats, we found that gadolinium (10 mM; 1 ml) significantly attenuated the renal sympathetic nerve and pressor responses to static contraction (60 s) after a latent period of 60 min; both responses recovered after a latent period of 120 min. We conclude that thin-fiber mechanoreceptors supplying contracting muscle are involved in some of the renal vasoconstriction evoked by the exercise pressor reflex.