Perturbation analysis of tubuloglomerular feedback in hydropenic and hemorrhaged rats.
Perturbation analysis of tubuloglomerular feedback in hydropenic and hemorrhaged rats.
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缺水和出血大鼠肾小管肾小球反馈的扰动分析。
DOI：
10.1152/ajprenal.1983.245.5.f554
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Mason,J
中科院分区：
文献类型：
--
作者：
Moore,LC;Mason,J
采用闭环反馈方法研究了肾小管-肾小球反馈（TGF）对缺水和衰老大鼠SNGFR和远端液体输送的调节作用。未阻断的肾单位受到早期近端灌注先前收集的，菊糖，肾小管液在0，7.5，和15 nl/min，从而增加肾单位液体负荷。测量SNGFR、肾小管重吸收、近端小管内压和早期远端血流的变化。在灌注过程中，SNGFR降低，远端血流增加;对重吸收的影响是可变的。数据的分析表明，TGF和近端小管和亨利氏袢重吸收的变化的联合作用能够提供最大的56%的补偿的影响的扰动对远端交付在水缺乏大鼠和70%的补偿老年大鼠。在一组水缺乏大鼠中，发现重吸收显著下降，肾单位的总液体负荷，SNGFR加上灌注率，明显优于远端输送。该结果与用于估计TGF对所观察到的调节的贡献的模型的行为一致。结果表明，单独的TGF可以提供56%的补偿，在水肿和出血后的补偿显着更高的72%的扰动。结论是：1）TGF的特性足以导致远端液体输送和SNGFR的显著调节，2）出血增加TGF反应的强度，3）SNGFR和远端输送的TGF调节受到近端小管和Henle重吸收环变化的强烈影响。
A closed-feedback-loop method was used to investigate regulation of SNGFR and distal fluid delivery by tubuloglomerular feedback (TGF) in hydropenic and hemorrhaged rats. Unblocked nephrons were perturbed by early proximal perfusion of previously collected, inulin-free, tubular fluid at 0, 7.5, and 15 nl/min, thereby increasing nephron fluid load. The resultant changes in SNGFR, tubular reabsorption, proximal intratubular pressure, and early distal flow were measured. During perfusion, SNGFR decreased and distal flow increased; the effect on reabsorption was variable. Analysis of the data indicated that the combined action of TGF and changes in proximal tubule and Henle's loop reabsorption were able to provide a maximum of 56% compensation for the effect of the perturbation on distal delivery in hydropenic rats and 70% compensation in hemorrhaged rats. In one group of hydropenic rats in which a significant fall in reabsorption was found, the total fluid load presented to the nephron, SNGFR plus the perfusion rate, was significantly better regulated than distal delivery. This result is consistent with the behavior of a model used to estimate the contribution of TGF to the observed regulation. The results indicated that TGF alone could provide 56% compensation for the perturbation in hydropenia and a significantly greater 72% compensation following hemorrhage. The conclusions are 1) that the properties of TGF are sufficient to result in significant regulation of distal fluid delivery and SNGFR, 2) that hemorrhage increases the strength of the TGF response, and 3) that TGF regulation of SNGFR and distal delivery is strongly influenced by changes in proximal tubule and loop of Henle reabsorption.