CELL-TRANSFORMATION INDUCES A CYTOPLASMIC CA2-DARBY CANINE KIDNEY-CELLS( OSCILLATOR IN MADIN)

Citation
L. Wojnowski et al., CELL-TRANSFORMATION INDUCES A CYTOPLASMIC CA2-DARBY CANINE KIDNEY-CELLS( OSCILLATOR IN MADIN), Pflugers Archiv, 426(1-2), 1994, pp. 89-94
Citations number
28
Categorie Soggetti
Physiology
Journal title
ISSN journal
00316768
Volume
426
Issue
1-2
Year of publication
1994
Pages
89 - 94
Database
ISI
SICI code
0031-6768(1994)426:1-2<89:CIACCC>2.0.ZU;2-I
Abstract
Alkaline stress transforms Madin-Darby canine kidney (MDCK) cells as i ndicated by loss of epithelial structure, multilayer cell growth and f ormation of foci. In the present study we report that transformed MDCK cells (MDCK-F cells) exhibit spontaneous and lasting oscillations of intracellular Ca2+ concentration ([Ca2+](i)), which are absent in non- transformed cells. Oscillations, as revealed by Fura-2 video imaging, were due to the activity of an inositol 1,4,5-trisphosphate-(InsP(3))- sensitive Ca2+ store since their frequency was dependent on bradykinin concentration and they were abolished by the phosphoinositidase C inh ibitor U73122. Moreover, blockers of the cytoplasmic Ca2+-ATPase, thap sigargin and 2,5-di-(tetr-butyl)-1,4-benzohydroquinone inhibited oscil latory activity. In contrast, neither injection of ruthenium red, ryan odine nor caffeine had any effect on oscillations. Analysis of the spa tial distribution of [Ca2+](i) showed that Ca2+ transients originated from an initiation site constant for a given cell and spread through t he cell as an advancing Ca2+ wave. Oscillations started in a random ma nner from single cells and spread over neighbouring cells, suggesting a kind of intercellular communication. We conclude that MDCK-F cells h ave acquired the ability for endogenous Ca2+ release through transform ation. Oscillations are primarily due to the activity of an InsP(3)-se nsitive cytosolic Ca2+ oscillator.