Intracellular pH regulation in detubulated frog skeletal muscle fibers.
Intracellular pH regulation in detubulated frog skeletal muscle fibers.
复制标题
去管青蛙骨骼肌纤维的细胞内 pH 调节。
DOI：
10.1152/ajpcell.1996.271.4.c1358
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Putnam,RW
中科院分区：
文献类型：
--
作者：
Putnam,RW
Intracellular pH regulation was studied in semitendinosus muscle fibers from frog (Rana pipiens). Intracellular pH (pHi) was measured with recessed-tip glass microelectrodes and membrane potential with conventional microelectrodes. Fibers had their connections between the surface and transverse tubular membrane disrupted (detubulation) with the formamide shock technique. Fibers were approximately 80% detubulated as determined by the decrease in membrane capacitance and the loss of contractile capability. The initial rate of pHi recovery from acidification to approximately 6.8 (no CO2) was dependent on external buffering power, reaching a maximum of approximately 0.6 pH/h at 50 mM HEPES, indicating that the rate of pHi recovery in frog muscle is limited by the diffusion of buffer through an external "unstirred layer". In detubulated fibers, pHi recovery from acidification due to both the amiloride-sensitive Na+/H+ and the 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS)-sensitive (Na+ + HCO3-)/Cl- exchangers was nearly identical to recovery in fully tubulated fibers. This is consistent with these two pH recovery transporters being localized to the surface, and not the transverse tubular, membrane domain in frog skeletal muscle fibers.
