Barajas L, Powers K V
Department of Pathology, Harbor-University of California, Los Angeles Medical Center, Torrance 90509.
Am J Physiol. 1988 Aug;255(2 Pt 2):F340-8. doi: 10.1152/ajprenal.1988.255.2.F340.
The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons.
利用氚标记的去甲肾上腺素标记单胺能神经，在大鼠肾脏切片的放射自显影片中，测量了髓袢升支粗段（TALH）轮廓上放射自显影颗粒（AAG）聚集的重叠情况。AAG重叠量被用作一种间接手段，来量化浅表肾单位、皮质中层肾单位和近髓肾单位TALH的神经支配情况。TALH的神经支配密度显示出肾单位的异质性；近髓肾单位在肾小球旁器（JGA）前后的TALH神经支配密度较高，而皮质上、中层肾单位在JGA水平的TALH神经支配密度较高。近髓肾单位的JGA前TALH的神经支配密度显著高于皮质中层或浅表肾单位（P小于0.001）。发现近髓肾单位的TALH比其他肾单位的TALH具有更多的神经支配。对于所有三种肾单位群体，JGA前TALH的神经支配量最大。TALH功能的神经调节主要发生在JGA前和JGA水平的TALH。这种调节会增加TALH对NaCl的重吸收（降低管腔内NaCl浓度），因此会影响1）尿液浓缩机制，以及2）通过致密斑机制分泌肾素。TALH的神经支配主要与自身肾单位的血管系统相关。然而，在浅表和皮质中层肾单位的JGA前TALH上，观察到了与更深层肾单位的髓放线毛细血管床相关的神经支配。
