Involvement of intracellular Ca(2+) in the regulatory volume decrease after hyposmotic swelling in MDCK cells.
We examined the source of Ca(2+) involved in the volume regulation of Madin-Darby canine kidney (MDCK) cells with confocal microscopy and fluoroprobes. Hyposmosis induced a transient increase in cell volume, as well as cytoplasmic Ca(2+), which peaked at 3 to 5 min and gradually decreased to reach the initial value within about 30 min. This late decrease in cell volume, as well as the transient rise in cytoplasmic Ca(2+), was reduced in Ca(2+)-free solution and was abolished by pretreatment with thapsigargin. In conclusion, Ca(2+) released from the intracellular store contributes to the regulatory volume decrease following hyposmotic swelling in MDCK cells.
Iida-Tanaka
Naoko
N
Department of Food Science, Faculty of Home Economics, Otsuma Woman's University, Tokyo, Japan.
Namekata
Iyuki
I
Kaneko
Megumi
M
Tamura
Miku
M
Kawanishi
Toru
T
Nakamura
Ryu
R
Shigenobu
Koki
K
Tanaka
Hikaru
H
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D048429:Cell Size; D004285:Dogs; D007668:Kidney / Q000166:cytology*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009994:Osmolar Concentration; D019284:Thapsigargin; D013997:Time Factors
D019284:Thapsigargin; D002118:Calcium