美西螈近端小管抗腔面膜的电生理研究：无机阴离子和硫氰酸盐的作用

Electrophysiological study of the antiluminal membrane in the proximal tubule of Necturus: effect of inorganic anions and SCN-.

作者信息

Anagnostopoulos T

出版信息

J Physiol. 1977 May;267(1):89-111. doi: 10.1113/jphysiol.1977.sp011803.

DOI:10.1113/jphysiol.1977.sp011803

PMID:874865

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1283604/

Abstract

A study has been made of the effects of anionic substitutions on the electrical potential difference (p.d.) and conductance characteristics of the antiluminal (peritubular) membrane of the proximal tubule of Necturus kidney. The tubular lumina were filled with oil in order to minimize potential and conductance contributions from luminal membrane and from paracellular shunt pathway.2. Isosmotic substitutions, A for Cl, produced the following average changes in membrane p.d. (mV): F(-) +1.7, BrO(3) (-) +0.1, Br(-) -4.5, ClO(3) (-) -5.2, I(-) -7.9, NO(3) (-) -12.1, ClO(4) (-) -17.8, SCN(-) -25.3.3. The amplitude of the depolarization caused by increase in K concentration (K-depolarization) in the peritubular perfusate was found to increase during perfusion of the tissue with ClO(4) (-) (by 78%), SCN(-) (45%), I(-) (23%), NO(3) (-) (20%), Br(-) (16%); it decreased with F(-) (by 17%).4. Comparison of membrane p.d. at peak K-depolarization in the control state (during KCl perfusion) with that obtained in the experimental state (during KA perfusion) was found to be more reliable than determination of bi-ionic potentials as a qualitative estimate of the permeabilities of the various anions (P(A)) relative to that of chloride (P(Cl)).5. Study of both peak K-depolarization p.d. and bi-ionic potentials yielded the following sequence for halide anion permeabilities: P(F) > P(Cl) > P(Br) > P(I). The peritubular membrane was found to be substantially more permeable to NO(3) (-), ClO(4) (-) and SCN(-) than to Cl(-).6. The sequence of membrane conductances during anionic substitutions was Cl(-) approximately BrO(3) (-) < Br(-) </= ClO(3) (-) < I(-) approximately F(-) < NO(3) (-) < ClO(4) (-) < SCN(-).7. From the changes in p.d. induced by K-depolarization, the absolute values of p.d. at peak K-depolarization and from the changes in membrane conductance induced by anionic substitutions, it may be inferred that Br(-), I(-), NO(3) (-), ClO(4) (-) and SCN(-) all increase P(K); and that F(-) increases P(Na) (though a smaller increase in P(K) cannot be excluded).

摘要

研究了阴离子取代对美西螈肾近端小管抗腔面膜（周细胞侧膜）的电势差（p.d.）和电导特性的影响。为了尽量减少腔面膜和细胞旁分流途径对电势和电导的贡献，将肾小管腔充满油。
等渗取代，即A取代Cl，导致膜电势差（mV）产生以下平均变化：F(-) +1.7，BrO₃(-) +0.1，Br(-) -4.5，ClO₃(-) -5.2，I(-) -7.9，NO₃(-) -12.1，ClO₄(-) -17.8，SCN(-) -25.3。
发现在用ClO₄(-)（增加78%）、SCN(-)（45%）、I(-)（23%）、NO₃(-)（20%）、Br(-)（16%）灌注组织期间，周细胞灌注液中K浓度增加（K去极化）引起的去极化幅度增大；而用F(-)灌注时（减少17%）则减小。
发现将对照状态（KCl灌注期间）的K去极化峰值时的膜电势差与实验状态（KA灌注期间）获得的膜电势差进行比较，比测定双离子电势作为各种阴离子（P(A)）相对于氯离子（P(Cl)）渗透性的定性估计更可靠。
对K去极化峰值电势差和双离子电势的研究得出卤化物阴离子渗透性的以下顺序：P(F) > P(Cl) > P(Br) > P(I)。发现周细胞侧膜对NO₃(-)、ClO₄(-)和SCN(-)的渗透性比对Cl(-)的渗透性大得多。
阴离子取代期间膜电导的顺序为Cl(-)≈BrO₃(-) < Br(-)≤ClO₃(-) < I(-)≈F(-) < NO₃(-) < ClO₄(-) < SCN(-)。
根据K去极化引起的电势差变化、K去极化峰值时的电势差绝对值以及阴离子取代引起的膜电导变化，可以推断Br(-)、I(-)、NO₃(-)、ClO₄(-)和SCN(-)均增加P(K)；而F(-)增加P(Na)（尽管不能排除对P(K)有较小增加）。