TY - JOUR
T1 - Impact of mitochondrial Ca2+ cycling on pattern formation and stability
AU - Falcke, M.
AU - Hudson, J. L.
AU - Camacho, P.
AU - Lechleiter, James D.
N1 - Funding Information:
This work was supported by National Institutes of Health Grant R01GM48451 (to J.L.). Animal care was in accordance with institutional guidelines.
PY - 1999/7
Y1 - 1999/7
N2 - 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.
AB - 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.
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U2 - 10.1016/S0006-3495(99)76870-0
DO - 10.1016/S0006-3495(99)76870-0
M3 - Article
C2 - 10388738
AN - SCOPUS:0032587030
VL - 77
SP - 37
EP - 44
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 1
ER -