Proton permeation through the myocardial gap junction.
Proton permeation through the myocardial gap junction.
复制标题
质子透过心肌间隙连接。
DOI：
10.1161/01.res.0000093986.47383.ce
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Vaughan-Jones,RichardD
中科院分区：
文献类型：
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作者：
Zaniboni,Massimiliano;Rossini,Alessandra;Swietach,Pawel;Banger,Nurindura;Spitzer,KennethW;Vaughan-Jones,RichardD
虽然质子可以直接或间接门心肌间隙连接的溶质渗透性，有很少的信息，关于他们自己的渗透，尽管他们在调节心肌收缩力和节奏的重要性。通过用移液管将酸加载到豚鼠分离的心室肌细胞对中，同时使用SNARF荧光进行pHiconfocally成像，我们观察到质子渗透连接区域。渗透被大黄酸抑制，大黄酸是一种也增加细胞间电阻的试剂，表明H+通过间隙连接渗透。酸在细胞间的扩散速率似乎受连接渗透而不是细胞质扩散的限制。数学分析，结合使用SNARF作为质子载体的实验，表明间隙连接H+传输可能是通过内在的“质子转运体”分子的渗透生理完成的。我们认为，质子通量通过缝隙连接将有助于消散区域内的心肌酸负荷。这代表了心肌pHi的局部控制机制。
Although protons can directly or indirectly gate solute permeability of the myocardial gap junction, there is little information regarding their own permeation, despite their importance in the regulation of myocardial contractility and rhythm. By pipette-loading of acid into guinea pig isolated, ventricular myocyte pairs while imaging pHiconfocally using SNARF fluorescence, we have observed that protons permeate the junctional region. Permeation is inhibited by glycyrrhetinic acid, an agent that also increases intercellular electrical resistance, suggesting H+permeation via gap junctions. The rate of spread of acid between cells appears to be limited by junctional permeation rather than by cytoplasmic diffusion. Mathematical analyses, combined with experiments using SNARF as a proton carrier, suggest that gap junctional H+transmission may be accomplished physiologically by the permeation of intrinsic “proton-porter” molecules. We propose that proton flux through gap junctions will contribute to the dissipation of regional acid loads within the myocardium. This represents a mechanism for the local control of myocardial pHi.