Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, Denmark.
Am J Physiol Renal Physiol. 2011 Feb;300(2):F319-29. doi: 10.1152/ajprenal.00417.2010. Epub 2010 Nov 3.
Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50-100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney.
管球反馈（TGF）在肾血流量和肾小球滤过率（GFR）的自动调节中起着重要作用。由于反馈环中信号传输的特点，TGF 在单个肾单位的血流、GFR 和管状压力和流量中会发生自我维持的振荡。通过在血管壁细胞中进行电传导的电信号进行交换，肾单位相互作用，导致 TGF 介导的振荡同步。这些相互作用的实验研究仅限于同时观察两个或最多三个肾单位。相互作用的肾单位区域可能更广泛。我们已经转向激光散斑对比成像，以测量麻醉大鼠肾脏表面 50-100 个肾单位的血流动力学。我们报告了该方法的应用，并描述了提取所需数据的分析技术，并检查了它们是否存在肾单位同步的证据。在成对或三对肾单位中检测到同步的 TGF 振荡。振荡的幅度和频率随时间变化，同步的模式也随之变化。同步可能发生在肾脏表面上不直接相邻的肾单位之间。
