RENAL PROXIMAL TUBULE OF FLOUNDER .1. PHYSIOLOGICAL-PROPERTIES
RENAL PROXIMAL TUBULE OF FLOUNDER .1. PHYSIOLOGICAL-PROPERTIES
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DOI：
10.1152/ajpregu.1986.250.4.r608
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发表时间：
1986-04-01
影响因子：
--
通讯作者：
CLIFF, WH
中科院分区：
文献类型：
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作者：
BEYENBACH, KW;PETZEL, DH;CLIFF, WH
对美洲拟鲽（P. americanus）的近端节进行了研究。孤立的小管净分泌液体，尽管速率较低，37 pl. cntdot. min-1。分泌液中的主要离子是Na和Cl，[Cl]显著高于浴中。分泌液中的Mg和SO 4浓度比浴中高10倍以上。跨上皮电压（-1.9mV）和电阻（26 Ω）. cntdot. cm 2）表明上皮有电渗漏，跨上皮扩散电位表明细胞旁途径的Na选择性。跨上皮电化学电位表明Mg、SO 4和可能的Cl的主动转运以及Na的跨上皮平衡。在体外以常用的灌注速率灌注的小管中未能观察到任何分泌转运，这说明了在通过布尔格的方法检测和研究低容量上皮转运系统时，低（优选亚纳升）灌注速率的必要性。
The proximal segment of the winter flounder, P. americanus, was investigated. Isolated tubules net secrete fluid, although at low rates, 37 pl .cntdot. min-1. The dominant ions in secreted fluid are Na and Cl, with [Cl] significantly higher than in the bath. Mg and SO4 concentrations in secreted fluid are more than 10-fold greater than in the bath. The transepithelial voltage (-1.9 mV) and resistance (26 .OMEGA. .cntdot. cm2) indicate an electrically leaky epithelium, and transepithelial diffusion potentials suggest the Na selectivity of the paracellular pathway. Transepithelial electrochemical potentials point to active transport of Mg, SO4, and probalby also Cl and to transepithelial equilibrium of Na. Failure to observe any secretory transport in tubules perfused in vitro at the commonly used perfusion rates illustrates the necessity of low, preferably subnanoliter, perfusion rates in detecting and studying low-capacity epithelial transport systems by the method of Burg.