Effects of pCai and pHi on cell-to-cell coupling.
Effects of pCai and pHi on cell-to-cell coupling.
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pCai 和 pHi 对细胞间耦合的影响。
DOI：
10.1007/bf01956044
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Pressler,ML
中科院分区：
文献类型：
--
作者：
Pressler,ML
内部纵向电阻（ri）是心脏传导的决定因素，受到细胞内钙和质子变化的影响。然而，H+和Ca ~（2+）可能调节ris的作用和机制尚不清楚。在心脏浦肯野纤维中进行电缆分析，以测量各种干预过程中的电流。在一些实验中，同时记录细胞内pH（pHi）以研究pHi-r关系。细胞内Ca ~（2+）和H ~+都独立地修饰了ri。然而，与其他组织相比，心脏纤维的内阻对pH变化不敏感。一个潜伏期之前的pH值相关的变化和变化量取决于方法。结果表明，质子对Ri的直接作用可能从属于其他调节过程。内部纵向电阻的离子调节可能通过一种以上的机制发生：i）直接阳离子结合到连接膜蛋白上的位点;和ii）连接蛋白的H+或Ca 2+依赖性磷酸化。
Internal longitudinal resistance (ri), a determinant of cardiac conduction, is affected by changes in intracellular calcium and protons. However, the role and mechanism by which H+and Ca2+may modulate riis uncertain. Cable analysis was performed in cardiac Purkinje fibers to measure riduring various interventions. In some experiments, intracellular pH (pHi) was recorded simultaneously to study the pHi-rirelation. Both intracellular Ca2+and H+independently modified ri. However, internal resistance of cardiac fibers was insensitive to pHichanges compared to other tissues. A latent period preceded the pHi-related changes in riand the amount of change depended upon methodology. The results suggest that direct action of protons on rimay be subordinate to other regulatory processes. Ionic regulation of internal longitudinal resistance may occur by more than one mechanism: i) direct cationic binding to sites on junctional membrane proteins; and ii) H+- or Ca2+-dependent phosphorylation of junctional proteins.