S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Physiology (생리학교실) Journal Papers (저널논문_생리학교실)
Voltage-dependent slowly activating anion current regulated by temperature and extracellular pH in mouse B cells
- Nam, Joo Hyun; Zheng, Hai Feng; Earm, Ki Hyun; Ko, Jae Hong; Lee, Ik-Jae; Kang, Tong Mook; Kim, Tae Jin; Earm, Young E.; Kim, Sung Joon
- Issue Date
- Springer Verlag
- Pflugers Arch. 2006 Sep;452(6):707-17. Epub 2006 Jun 7.
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid/pharmacology; Adenosine Triphosphate/metabolism; Animals; Anti-Inflammatory Agents, Non-Steroidal/pharmacology; B-Lymphocytes/*physiology; Cell Line; Electrophysiology; Hydrogen-Ion Concentration; Ion Channels/*physiology; Kinetics; Membrane Potentials/physiology; Mice; Patch-Clamp Techniques; Niflumic Acid/pharmacology; Temperature
- Voltage-dependent, outwardly rectifying anion channels have been described in various cells including lymphocytes. In this study, we found that murine B cells express the voltage-dependent slowly activating anion channels (VSACs). Using a whole-cell configuration, I (VSAC) in Bal-17 was induced by a sustained depolarization (>0 mV) which was remarkably facilitated at 35 degrees C (Q (10)=23 at 30 mV of clamp voltage). Substitution of extracellular Cl(-) with gluconate shifted the reversal potential to the right (35.7 mV). Gd(3+) (IC(50)=0.11 microM) significantly attenuated I (VSAC), but DIDS partially blocked I (VSAC). In addition, extracellular acidification suppressed I (VSAC) whereas alkalinization facilitated the channel activation. I (VSAC) was decreased by 90% at pH 6.35 and increased by 180% at pH 8.0. In cell-attached and inside-out patch clamps, depolarization slowly activated the anion channels of large conductance (approximately 270 pS) with multiple levels of subconductances. The single channel currents were also blocked by Gd(3+) and acidic pH. Furthermore, I (VSAC) was also observed in WEHI-231 (an immature B cell line) and freshly isolated splenic B cells of mice. In summary, murine B cells express unique voltage-dependent anion channels that show a strong sensitivity to both temperature and extracellular pH. Further investigation is required to understand the physiological roles of VSAC and its molecular identity.
- 0031-6768 (Print)
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