Ca(2+)-activated K+ Channels Are Involved in Regulatory Volume Decrease in Acinar Cells Isolated from the Rat Lacrimal Gland
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The volumes of acinar cells isolated from rat lacrimal gland were measured on computer by video-imaging. Cells were found to swell on exposure to hypotonic solutions; they subsequently exhibited a regulatory volume decrease (RVD). RVD was inhibited in the absence of extracellular Ca2+, and by the K+ channel blocker tetraethylammonium chloride (2 mM TEA+). The possible involvement of K+ channels in RVD was further investigated in cell-attached patches. Exposing the cells to a hypotonic solution activated channels with a conductance of 141 +/- 6 pS (n = 11). These channels were partially blocked by 0.5 mM TEA+, and channel activation was not observed in the absence of extracellular Ca2+. Experiments in the inside-out patch configuration demonstrated that the channels activated by hypotonic stress were "maxi" Ca(2+)-activated K+ channels. It is concluded that the opening of these channels plays an important role in RVD, by facilitating K+ loss from the cell.
Piezo1, the new actor in cell volume regulation.
Michelucci A, Catacuzzeno L Pflugers Arch. 2024; 476(7):1023-1039.
PMID: 38581527 PMC: 11166825. DOI: 10.1007/s00424-024-02951-y.
Venglovecz V, Rakonczay Jr Z, Gray M, Hegyi P Pflugers Arch. 2014; 467(4):625-40.
PMID: 25074489 DOI: 10.1007/s00424-014-1585-0.
Pan Z, Yang H, Mergler S, Liu H, Tachado S, Zhang F Cell Calcium. 2008; 44(4):374-85.
PMID: 18355916 PMC: 2588056. DOI: 10.1016/j.ceca.2008.01.008.
Majid A, Brown P, Best L, Park K J Physiol. 2001; 534(Pt. 2):409-21.
PMID: 11454960 PMC: 2278701. DOI: 10.1111/j.1469-7793.2001.00409.x.
Niemeyer M, Hougaard C, Hoffmann E, Jorgensen F, Stutzin A, Sepulveda F J Physiol. 2000; 524 Pt 3:757-67.
PMID: 10790156 PMC: 2269893. DOI: 10.1111/j.1469-7793.2000.00757.x.