Impact of mitochondrial Ca2+ cycling on pattern formation and stability

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Item Type:	Article
Title:	Impact of mitochondrial Ca2+ cycling on pattern formation and stability
Creators Name:	Falcke, M., Hudson, J.L., Camacho, P. and Lechleiter, J.D.
Abstract:	Energization of mitochondria significantly alters the pattern of Ca2+ wave activity mediated by activation of the inositol (1,4,5) trisphosphate (IP3) receptor (IP3R) in Xenopus oocytes. The number of pulsatile foci is reduced and spiral Ca2+ waves are no longer observed. Rather, target patterns of Ca2+ release predominate, and when fragmented, fail to form spirals. Ca2+ wave velocity, amplitude, decay time, and periodicity are also increased. We have simulated these experimental findings by supplementing an existing mathematical model with a differential equation for mitochondrial Ca2+ uptake and release. Our calculations show that mitochondrial Ca2+ efflux plays a critical role in pattern formation by prolonging the recovery time of IP3Rs from a refractory state. We also show that under conditions of high energization of mitochondria, the Ca2+ dynamics can become bistable with a second stable stationary state of high resting Ca2+ concentration.
Keywords:	Calcium, Calcium Signaling, Cytosol, Inositol 1,4,5-Trisphosphate, Kinetics, Malates, Confocal Microscopy, Mitochondria, Theoretical Models, Oocytes, Pyruvic Acid, Animals, Xenopus
Source:	Biophysical Journal
ISSN:	0006-3495
Publisher:	Biophysical Society
Volume:	77
Number:	1
Page Range:	37-44
Date:	July 1999
Official Publication:	https://doi.org/10.1016/S0006-3495(99)76870-0
PubMed:	View item in PubMed

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