Sakai H, Okada Y, Morii M, Takeguchi N
Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
Pflugers Arch. 1989 Jun;414(2):185-92. doi: 10.1007/BF00580962.
Ion channels in the basolateral membrane of rabbit parietal cells in isolated gastric glands were studied by the patch clamp technique. Whole-cell current-clamp recordings showed that the membrane potential (Em) changed systematically as a function of the chloride concentrations of the basolateral bathing solution ([Cl-]0), and of the pipette (intracellular) solution. The relationship between Em and [Cl-]0 was not affected by additions of histamine, dibutyryl-cAMP, 4-acetoamido-4'-isothiocyanostilbene-2,2'-disulfonic acid and diphenylamine-2-carboxylate. The whole-cell Cl- conductance was insensitive to voltage. In cell-attached and cell-free patch membranes, however, single Cl- channel opening events could not be observed. The value of Em depended little on the basolateral K+ concentration, but inward-rectifier K+ currents were observed in the whole-cell configuration, activated by hyperpolarizing pulses and inhibited by extracellular Ba2+. In cell-attached and cell-free patches, openings of single inward-rectifier K+ channels and non-selective cation channels were infrequently recorded. Neither cAMP nor Ca2+ activated these cation channels. The single K+ channel conductance was about 230 pS under the symmetrical high K+ conditions and was inhibited by intracellular tetraethylammonium ions (TEA). The non-selective cation channel had a voltage-independent single conductance of 22 pS and was not inhibited by TEA.
采用膜片钳技术研究了分离胃腺中兔壁细胞基底外侧膜上的离子通道。全细胞电流钳记录显示，膜电位（Em）随基底外侧灌流液（[Cl-]0）和移液管（细胞内）溶液中氯离子浓度的变化而系统性改变。Em与[Cl-]0之间的关系不受组胺、二丁酰环磷腺苷、4-乙酰氨基-4'-异硫氰基芪-2,2'-二磺酸和二苯胺-2-羧酸盐添加的影响。全细胞Cl-电导对电压不敏感。然而，在细胞贴附膜和游离膜片上，未观察到单个Cl-通道开放事件。Em的值对基底外侧K+浓度的依赖性很小，但在全细胞模式下观察到内向整流K+电流，该电流由超极化脉冲激活并被细胞外Ba2+抑制。在细胞贴附膜和游离膜片中，很少记录到单个内向整流K+通道和非选择性阳离子通道的开放。环磷腺苷和Ca2+均未激活这些阳离子通道。在对称高K+条件下，单个K+通道电导约为230 pS，并被细胞内四乙铵离子（TEA）抑制。非选择性阳离子通道具有22 pS的电压非依赖性单通道电导，且不受TEA抑制。
