Park, KS Jo, I Pak, YK Bae, SW Rhim, H Suh, SH Park, SJ Zhu, MH So, I Kim, KW 2024-01-21T11:11:56Z 2024-01-21T11:11:56Z 2022-01-10 2002-01 0031-6768 https://pubs.kist.re.kr/handle/201004/139868 We investigated the effects of carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), a protonophore and uncoupler of mitochondrial oxidative phosphorylation in mitochondria, on plasma membrane potential and ionic currents in bovine aortic endothelial cells (BAECs). The membrane potential and ionic currents of BAECs were recorded using the patch-clamp technique in current-clamp and voltage-clamp modes, respectively. FCCP activated ionic currents and depolarized the plasma membrane potential in a dose-dependent manner. Neither the removal of extracellular Ca2+ nor pretreatment with BAPTA/AM affected the FCCP-induced currents, implying that the currents are not associated with the FCCP-induced intracellular [Ca2+](i) increase. FCCP-induced currents were significantly influenced by the changes in extracellular or intracellular pH the increased proton gradient produced by lowering the extracellular pH or intracellular alkalinization augmented, the changes in membrane potential and ionic currents caused by FCCP. FCCP-induced currents were significantly reduced under extracellular Na+-free conditions. The reversal potentials of FCCP-induced currents under Na+-free conditions were well fitted to the calculated equilibrium potential for protons. Interestingly, FCCP-induced Na+ transport (subtracted currents, I-control-INa +-free) was closely dependent on extracellular pH, whereas FCCP-induced H+ transport was not significantly affected by the absence of Na+. These results suggest that the FCCP-induced ionic currents and depolarization, which are strongly dependent on the plasmalemmal proton gradient, are likely to be mediated by both H+ and Na+ currents across the plasma membrane. The relationship between H+ and Na+ transport still needs to be determined. English SPRINGER HEIDELBERG RAT HIPPOCAMPAL-NEURONS BODY GLOMUS CELLS INTRACELLULAR CALCIUM METABOLIC INHIBITION ION CHANNELS MITOCHONDRIA PH ACIDIFICATION UNCOUPLERS <CA2+>(I) FCCP depolarizes plasma membrane potential by activating proton and Na+ currents in bovine aortic endothelial cells Article 10.1007/s004240100703 1 PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, v.443, no.3, pp.344 - 352 PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY 443 3 344 352 scie scopus 000173647700003 2-s2.0-0036158055 Physiology Physiology Article RAT HIPPOCAMPAL-NEURONS BODY GLOMUS CELLS INTRACELLULAR CALCIUM METABOLIC INHIBITION ION CHANNELS MITOCHONDRIA PH ACIDIFICATION UNCOUPLERS <CA2+>(I) bovine aortic endothelial cells FCCP H+ current Na+ current plasma membrane depolarization