Rodeau J L, Flament S, Browaeys E, Vilain J P
Laboratoire de Neurobiologie Cellulaire, CNRS UPR 9009, Strasbourg, France.
Mol Membr Biol. 1998 Jul-Sep;15(3):145-51. doi: 10.3109/09687689809074526.
The effect of the local anaesthetic procaine on the intracellular pH, pHi, and electrophysiological properties of full-grown Xenopus oocytes was studied. In spite of its interference with both the pH-sensitive microelectrodes and fluorescent probe BCECF, we have shown that procaine induced an intracellular acidification rather than the alkalization commonly observed in most cells. The resting pHi of Xenopus oocytes loaded with BCECF was 7.36 +/- 0.04 (n = 16). Addition of 10 mM procaine to the bath at pH 7.5 caused pHi to decrease to a new steady state value of 6.97 +/- 0.05 (n = 9). A similar behaviour of pHi was observed with microelectrodes. Procaine also promoted a rise in membrane conductance and a membrane depolarization. These changes in membrane potential and conductance were not caused by the decrease in pHi since the addition of sodium propionate at pH 7.5 produced the same decrease of pHi as procaine, but resulted in only a slight depolarization with superimposed oscillations. Current measurements using two-electrode voltage clamp showed that the depolarization was associated with an inward current. No significant effect on this current was observed when replacing Cl, K or Na in the external medium. The absence of effect of Cl and K channel inhibitors argues against the involvement of Cl and K currents during the procaine response.
研究了局部麻醉药普鲁卡因对成熟非洲爪蟾卵母细胞的细胞内pH值（pHi）和电生理特性的影响。尽管它会干扰pH敏感微电极和荧光探针BCECF，但我们已经表明，普鲁卡因会引起细胞内酸化，而不是大多数细胞中常见的碱化。用BCECF加载的非洲爪蟾卵母细胞的静息pHi为7.36±0.04（n = 16）。在pH 7.5的浴液中加入10 mM普鲁卡因会导致pHi降低至新的稳态值6.97±0.05（n = 9）。用微电极观察到pHi有类似的变化。普鲁卡因还会促进膜电导增加和膜去极化。膜电位和电导的这些变化不是由pHi降低引起的，因为在pH 7.5加入丙酸钠产生的pHi降低与普鲁卡因相同，但仅导致轻微的去极化并伴有叠加振荡。使用双电极电压钳进行的电流测量表明去极化与内向电流有关。当在外部介质中替换Cl、K或Na时，未观察到对该电流有显著影响。Cl和K通道抑制剂无作用表明在普鲁卡因反应过程中Cl和K电流未参与。
