Coutinho-Silva R, Persechini P M
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brasil.
Am J Physiol. 1997 Dec;273(6):C1793-800. doi: 10.1152/ajpcell.1997.273.6.C1793.
Millimolar concentrations of extracellular ATP (ATPo) can induce the permeabilization of plasma membranes of macrophages and other bone marrow-derived cells to low-molecular-weight solutes, a phenomenon that is the hallmark of P2Z purinoceptors. However, patch-clamp and whole cell electrophysiological experiments have so far failed to demonstrate the existence of any ATPo-induced P2Z-associated pores underlying this permeabilization phenomenon. Here, we describe ATPo-induced pores of 409 +/- 33 pS recorded using cell-attached patch-clamp experiments performed in macrophages and J774 cells. These pores are voltage dependent and display several properties of the P2Z-associated permeabilization phenomenon: they are permeable to both large cations and anions, such as tris(hydroxymethyl)aminomethane, N-methyl-D-glucamine, and glutamate; their opening is favored at temperatures higher than 30 degrees C; they are blocked by oxidized ATP and Mg2+; and they can be triggered by 3'-O-(4-benzoylbenzoyl)-ATP but not by UTP or ADP. We conclude that the pores described in this report are associated with the P2Z permeabilization phenomenon.
毫摩尔浓度的细胞外ATP（ATPo）可诱导巨噬细胞和其他骨髓来源细胞的质膜对低分子量溶质通透，这一现象是P2Z嘌呤受体的标志。然而，迄今为止，膜片钳和全细胞电生理实验未能证明这种通透现象背后存在任何由ATPo诱导的与P2Z相关的孔。在此，我们描述了在巨噬细胞和J774细胞中使用细胞贴附式膜片钳实验记录到的由ATPo诱导的409 +/- 33 pS的孔。这些孔是电压依赖性的，并表现出与P2Z相关的通透现象的几个特性：它们对大阳离子和阴离子都通透，如三（羟甲基）氨基甲烷、N-甲基-D-葡糖胺和谷氨酸；在高于30摄氏度的温度下更容易开放；它们被氧化ATP和Mg2+阻断；并且它们可由3'-O-（4-苯甲酰苯甲酰）-ATP触发，但不能由UTP或ADP触发。我们得出结论，本报告中描述的孔与P2Z通透现象相关。
