Mural propagation of descending vasa recta responses to mechanical stimulation.
Mural propagation of descending vasa recta responses to mechanical stimulation.
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降直血管对机械刺激的反应的壁传播。
DOI：
10.1152/ajprenal.00220.2013
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Pallone,ThomasL
中科院分区：
文献类型：
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作者：
Zhang,Zhong;Payne,Kristie;Cao,Chunhua;Pallone,ThomasL
为了研究下行直血管（DVR）对近腔表面变形的反应，我们设计了一种自动化方法，该方法通过利用来自微量移液管的缓冲液流来控制刺激的持续时间和频率。在血管一端刺激期间，从远处细胞记录到fluor 4或双[1，3-二丁基巴比妥酸-（5）] trimethineoxonol [DiBAC 4（3）]的荧光反应，分别指示细胞质钙（[Ca 2 +]CYT）或膜电位。或者，通过制霉菌素全细胞膜片钳记录DVR周细胞的膜电位。机械刺激引起可逆的[Ca 2 +] CYP反应，随频率增加。单个周细胞的反应沿着血管内发起的一个又一个的几分之一秒。用18 β-大黄酸（100 μM）阻断间隙连接或用2-吗啉-4-基-8-苯基苯并吡喃-4-酮（50 μM）抑制磷酸肌醇3激酶可抑制这些反应。[Ca2+]通过用硝苯地平（10 μM）去除细胞外Ca 2+或L型电压门控通道阻断剂来阻断CYP反应。在对T型通道阻断具有选择性的浓度下，米贝拉地尔（100 nM）无效。在机械刺激过程中，周细胞迅速去极化，如DiBAC 4（3）荧光或膜片钳记录所示。单次刺激产生22.5 ± 2.2 mV的去极化，而0.1 Hz的重复刺激使周细胞去极化44.2 ± 4.0 mV。我们得出结论，DVR是机械敏感的，信号的快速传输沿着血管轴需要参与的间隙连接，L型钙通道，和周细胞去极化。
To investigate the responses of descending vasa recta (DVR) to deformation of the abluminal surface, we devised an automated method that controls duration and frequency of stimulation by utilizing a stream of buffer from a micropipette. During stimulation at one end of the vessel, fluorescent responses from fluo4 or bis[1,3-dibutylbarbituric acid-(5)] trimethineoxonol [DiBAC4(3)], indicating cytoplasmic calcium ([Ca2+]CYT) or membrane potential, respectively, were recorded from distant cells. Alternately, membrane potential was recorded from DVR pericytes by nystatin whole cell patch-clamp. Mechanical stimulation elicited reversible [Ca2+]CYTresponses that increased with frequency. Individual pericyte responses along the vessel were initiated within a fraction of a second of one another. Those responses were inhibited by gap junction blockade with 18 β-glycyrrhetinic acid (100 μM) or phosphoinositide 3 kinase inhibition with 2-morpholin-4-yl-8-phenylchromen-4-one (50 μM). [Ca2+]CYTresponses were blocked by removal of extracellular Ca2+or L-type voltage-gated channel blockade with nifedipine (10 μM). At concentrations selective for the T-type channel blockade, mibefradil (100 nM) was ineffective. During mechanostimulation, pericytes rapidly depolarized, as documented with either DiBAC4(3) fluorescence or patch-clamp recording. Single stimuli yielded depolarizations of 22.5 ± 2.2 mV while repetitive stimuli at 0.1 Hz depolarized pericytes by 44.2 ± 4.0 mV. We conclude that DVR are mechanosensitive and that rapid transmission of signals along the vessel axis requires participation of gap junctions, L-type Ca2+channels, and pericyte depolarization.