Juxtamedullary afferent and efferent arterioles constrict to renal nerve stimulation.
Juxtamedullary afferent and efferent arterioles constrict to renal nerve stimulation.
复制标题
近髓传入和传出小动脉收缩以刺激肾神经。
DOI：
10.1038/ki.1993.301
复制
发表时间：
1993
影响因子：
19.6
通讯作者：
Fleming,JT
中科院分区：
文献类型：
--
作者：
Chen,J;Fleming,JT
髓旁传入和传出小动脉在肾神经刺激下收缩。交感神经对内皮质（髓旁）肾小球传入和传出小动脉的控制尚未建立，部分原因是难以进入这些通常位于肾表面深处的血管。在本研究中，我们利用大鼠肾积水模型观察肾脏微循环，并量化髓旁小动脉对短暂（30秒）肾神经刺激（RNS）的反应。髓旁传入和传出小动脉以频率依赖的方式收缩RNS，达到35%至8 Hz刺激的最大收缩。在这些肾脏中，皮层外传入小动脉也收缩到RNS，但皮层外传出小动脉没有。在单个外皮层传出小动脉周围微注射去甲肾上腺素（NE）（以避免肾小球前血管收缩）使传出小动脉收缩。然而，同一肾小球的传入小动脉对微注射NE的反应明显更强。因此，皮层外传出小动脉对RNS缺乏收缩可能部分与它们对NE（主要神经递质）的低敏感性有关。这些直接观察表明，髓旁传出小动脉对肾神经刺激有反应，而皮质外传出血管则没有反应。这些结果应谨慎地推断到正常滤过肾，表明交感神经系统引起的肾小球血流动力学变化在外皮质肾小球和内皮质肾小球中是不同的。
Juxtamedullary afferent and efferent arterioles constrict to renal nerve stimulation. Sympathetic neural control of afferent and efferent arterioles of inner cortical (juxtamedullary) glomeruli has not been established, in part, because of difficulty accessing these vessels, normally located deep below the kidney surface. In this study we utilized the rat hydronephrotic kidney model to visualize the renal microcirculation and to quantitate the responses of juxtamedullary arterioles to brief (30 sec) renal nerve stimulation (RNS). Juxtamedullary afferent and efferent arterioles constricted in a frequency-dependent fashion to RNS, achieving a maximal constriction of 35% to 8 Hz stimulation. In these same kidneys, outer cortical afferent arterioles also constricted to RNS but outer cortical efferent arterioles did not. Microinjection of norepinephrine (NE) around single outer cortical efferent arterioles (to avoid the constriction of preglomerular vessels) constricted the efferent arterioles. However, the afferent arterioles of the same glomeruli were considerably more responsive to microinjected NE. Thus, the lack of constriction of outer cortical efferent arterioles to RNS may relate, in part, to their low sensitivity to NE, the primary neurotransmitter. These direct observations indicate that the juxtamedullary efferent arterioles are responsive to renal nerve stimulation whereas the outer cortical efferent vessels are not. These results, which should be cautiously extrapolated to normal filtering kidneys, indicate that glomerular hemodynamic changes evoked by the sympathetic nervous system are different for outer cortical and inner cortical glomeruli.