Regulatory volume decrease in cardiomyocytes is modulated by calcium influx and reactive oxygen species.
We investigated the role of Ca(2+) in generating reactive oxygen species (ROS) induced by hyposmotic stress (Hypo) and its relationship to regulatory volume decrease (RVD) in cardiomyocytes. Hypo-induced increases in cytoplasmic and mitochondrial Ca(2+). Nifedipine (Nife) inhibited both Hypo-induced Ca(2+) and ROS increases. Overexpression of catalase (CAT) induced RVD and a decrease in Hypo-induced blebs. Nife prevented CAT-dependent RVD activation. These results show a dual role of Hypo-induced Ca(2+) influx in the control of cardiomyocyte viability. Hypo-induced an intracellular Ca(2+) increase which activated RVD and inhibited necrotic blebbing thus favoring cell survival, while simultaneously increasing ROS generation, which in turn inhibited RVD and induced necrosis.
Rojas-Rivera
Diego
D
Centro FONDAP Estudios Moleculares de la Célula, Departamentos de, Santiago 838-0492, Chile.
Díaz-Elizondo
Jessica
J
Parra
Valentina
V
Salas
Daniela
D
Contreras
Ariel
A
Toro
Barbra
B
Chiong
Mario
M
Olea-Azar
Claudio
C
Lavandero
Sergio
S
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009336:Necrosis / Q000378:metabolism; D009997:Osmotic Pressure / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D002374:Catalase; D002118:Calcium