title: The death of ouabain-treated renal epithelial C11-MDCK cells is not mediated by swelling-induced plasma membrane rupture.
abstract: This study examined the role of cell volume modulation in plasma membrane rupture and death documented in ouabain-treated renal epithelial cells. Long-term exposure to ouabain caused massive death of C11-MDCK (Madin-Darby canine kidney) epithelial cells, documented by their detachment, chromatin cleavage and complete loss of lactate dehydrogenase (LDH), but did not affect the survival of vascular smooth muscle cells (VSMCs) from the rat aorta. Unlike the distinct impact on cell survival, 2-h exposure to ouabain led to sharp elevation of the [Na⁺](i)/[K⁺](i) ratio in both cell types. A similar increment of Na⁺(i) content was evoked by sustained inhibition of Na⁺,K⁺-ATPase in K⁺-free medium. However, in contrast to ouabain, C11-MDCK cells survived perfectly during 24-h exposure to K⁺-free medium. At 3 h, the volume of ouabain-treated C11-MDCK cells and VSMCs, measured by the recently developed dual-image surface reconstruction technique, was increased by 16 and 12%, respectively, whereas 5-10 min before the detachment of ouabain-treated C11-MDCK cells, their volume was augmented by ~30-40%. To examine the role of modest swelling in the plasma membrane rupture of ouabain-treated cells, we compared actions of hypotonic medium on volume and LDH release. We observed that LDH release from hypoosmotically swollen C11-MDCK cells was triggered when their volume was increased by approximately fivefold. Thus, our results showed that the rupture of plasma membranes in ouabain-treated C11-MDCK cells was not directly caused by cell volume modulation evoked by Na⁺,K⁺-ATPase inhibition and inversion of the [Na⁺](i)/[K⁺](i) ratio.
authors.affiliation: Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM)-Technopôle Angus, 2901 Rachel Est, Montreal, QC H1W4A4, Canada.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Platonova
authors.forename: Svetlana
authors.initials: S
authors.lastname: Koltsova
authors.forename: Georgy V
authors.initials: GV
authors.lastname: Maksimov
authors.forename: Ryszard
authors.initials: R
authors.lastname: Grygorczyk
authors.forename: Sergei N
authors.initials: SN
authors.lastname: Orlov
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D048429:Cell Size / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002843:Chromatin / Q000378:metabolism; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D017136:Ion Transport / Q000187:drug effects*; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D009995:Osmosis / Q000187:drug effects; D009997:Osmotic Pressure / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D012413:Rubidium / Q000378:metabolism; D012975:Sodium Isotopes / Q000378:metabolism; D012979:Sodium Radioisotopes / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D002843:Chromatin; D012975:Sodium Isotopes; D012979:Sodium Radioisotopes; D010042:Ouabain; D007770:L-Lactate Dehydrogenase; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium; D011188:Potassium