ROLE OF BICARBONATE, CHLORIDE AND SODIUM IONS IN REGULATION OF INTRACELLULAR PH IN SNAIL NEURONS
ROLE OF BICARBONATE, CHLORIDE AND SODIUM IONS IN REGULATION OF INTRACELLULAR PH IN SNAIL NEURONS
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DOI：
10.1113/jphysiol.1977.sp012096
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发表时间：
1977-01-01
影响因子：
5.5
通讯作者：
THOMAS, RC
中科院分区：
文献类型：
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作者：
THOMAS, RC
用离子敏感微电极记录了蜗牛神经元内pH（pHi）、Cl-和Na+水平，并探讨了内酸化恢复pHi的机制。降低外部HCO 3-浓度极大地抑制了从HCl注入中恢复pHi的速率。减少外部Cl-没有抑制pHi恢复，但减少内部Cl-，通过暴露于硫酸盐林格氏细胞，抑制从CO2应用的pHi恢复。在从CO2施用恢复pHi期间，内部Cl-浓度降低。测得的内部Cl-浓度下降平均约为内部HCO 3-计算增加的25%。去除外部Na抑制从CO2应用或HCl注射的pHi恢复。在从酸化中恢复pHi的过程中，内部Na+浓度（[Na+]i）增加，其大于Na泵被无钾林格氏液抑制时发生的增加。在从HCl注入的pHi恢复期间发生的[Na+]i的增加约为由NaCl的类似注入产生的增加的一半。无钠林格氏液和阴离子交换抑制剂SITS对盐酸注射后pHi恢复的抑制作用不是相加的。pHi调节系统涉及紧密相连的Cl--HCO 3-和Na+-H+交换，Na沿其浓度梯度进入可能提供驱动HCO 3-向内运动和Cl-和H+向外运动的能量。
Intracellular pH (pHi), Cl- and Na+ levels were recorded in snail [Helix aspersa] neurons using ion-sensitize micro-electrodes, and the mechanism of pHi recovery from internal acidification investigated. Reducing external HCO3- concentration greatly inhibited the rate of pHi recovery from HCl injection. Reducing external Cl- did not inhibit pHi recovery, but reducing internal Cl-, by exposing the cell to sulfate Ringer, inhibited pHi recovery from CO2 application. During pHi recovery from CO2 application, internal Cl- concentration decreased. The measured fall in internal Cl- concentration averaged about 25% of the calculated increase in internal HCO3-. Removal of external Na inhibited pHi recovery from CO2 application or HCl injection. During pHi recovery from acidification there was an increase in the internal Na+ concentration ([Na+]i) which was larger than that occurring when the Na pump was inhibited by K-free Ringer. The increase in [Na+]i that occurred during pHi recovery from an HCl injection was about half that produced by a similar injection of NaCl. The inhibitory effects of Na-free Ringer and of the anion exchange inhibitor SITS on pHi recovery after HCl injection were not additive. The pHi regulating system involves tightly linked Cl--HCO3- and Na+-H+ exchange, with Na entry down its concentration gradient probably providing the energy to drive inward movement of HCO3- and the outward movement of Cl- and H+.