新鲜分离小鼠胃ICC样细胞的鉴定及其电生理学特性

将免疫荧光及传统全细胞膜片钳技术应用于新鲜分离的小鼠胃Cajal 间质细胞样细胞上，探讨了小鼠胃Cajal 间质细胞样细胞形态和电生理学特性。经胶原酶消化得到的Cajal间质细胞样细胞胞体呈短梭形，且自胞体发出多个较短的毛刺状突起。免疫细胞化学结果表明，Cajal 间质细胞样细胞胞体和突起酪氨酸激酶受体c-kit表达呈阳性。在传统全细胞记录模式、膜电位钳制在-60 mV 的条件下，可以记录到自发、节律性内向电流，即起搏电流。钙调蛋白抑制剂W-7 (50µmol/L）明显增强了起搏电流幅度并引发明显的内向钳制电流。当电极内液中EGTA 的浓度由0.1 mmol/L增加到10 mmol/L时，也明显增强了起搏电流幅度并引发明显的内向钳制电流。实验结果提示，新鲜分离的小鼠胃Cajal 间质细胞样细胞可以产生自发、自律性内向电流，而这种电流对胞内低钙或钙调蛋白抑制剂敏感。这种具有自发性电活动的Cajal 间质细胞样细胞可能就是胃Cajal 间质细胞。

Identification and electrophysiological characteristic of freshly isolated ICC-like cells in murine stomach

In the present study, the morphological and electrophysiological characteristics were investigated by using immunohistochemical and conventional whole-cell patch clamp techniques in freshly isolated gastric interstitial cell of Cajal-like cells of murine. The isolated interstitial cell of Cajal-like cells exhibited many short hair-like projections on their short fusiform bodies. These cells were almost c-kit
protein immunopositive, and both soma and projections were stained obviously. Under the conventional whole-cell patch clamp configuration, membrane potential was held at -60 mV, and the spontaneous rhythmic inward currents (pacemaker currents) were elicited in interstitial cell of Cajal-like cells. W-7(50 µmol/L), a calmodulin inhibitor, significantly increased the amplitude of pacemaker currents and elicited sustained inward holding current in interstitial cell of Cajal-like cells. Intracellular low free calcium induced by high EGTA (10 mmol/L) in pipette also significantly enhanced the amplitude of pacemaker currents and elicited sustained inward holding current in interstitial cell of Cajal-like cells. The results suggested that spontaneous rhythmic inward currents can be elicited from freshly isolated interstitial cell of Cajal-like cells and these currents were sensitive to intracellular low calcium and calmodulin inhibitor. The interstitial cell of Cajal-like cells were likely to be gastric interstitial cell of Cajal.