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Updated: Jun 16, 2026

Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels
Published on: December 13, 2024
Regulation of intracellular pH by Ca2+-activated proton channel
1Department of Cosmetic Science, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan. kuotsung@mail.chna.edu.tw
Background And Aim:
We have characterized a membrane current associated with a decrease in pHi, which can be induced by either elevating intracellular calcium or extracellular application of methylmercury (a potent agent in elevating intracellular Ca(2+) concentration) in the alveolar macrophages bathing in the impermeant bilateral cesium aspartate solution.
Results:
Decreasing pHi and elevating [Ca(2+)]i profoundly enhanced, but H-7 (a broad-spectrum kinase inhibitor), W-7 (a selective calmodulin antagonist) and KN-93 (a calmodulin kinase II inhibitor) inhibited the currents.
Conclusion:
These results indicate that rat alveolar macrophages possess a calcium-activated and pHi-sensitive proton channel which can be phosphorylated and activated by calmodulin kinase II.
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