Journal Article


Dmitri B Papkovsky
Jochen H M Prehn
Dmitri M Chudakov
Ekaterina A Souslova
Cormac T. Taylor
Manus W Ward
Alexander V Zhdanov



sodium calcium exchanger pc12 cells extracellular space physiology calcium mitochondria membrane potential mitochondrial rats pharmacology oxygen consumption energy metabolism carbonyl cyanide p trifluoromethoxyphenylhydrazone animals metabolism

Extracellular calcium depletion transiently elevates oxygen consumption in neurosecretory PC12 cells through activation of mitochondrial Na+/Ca2+ exchange. (2010)

Abstract Fluctuating extracellular Ca2+ regulates many aspects of neuronal (patho)physiology including cell metabolism and respiration. Using fluorescence-based intracellular oxygen sensing technique, we demonstrate that depletion of extracellular Ca2+ from 1.8 to < or = 0.6 mM by chelation with EGTA induces a marked spike in O2 consumption in differentiated PC12 cells. This respiratory response is associated with the reduction in cytosolic and mitochondrial Ca2+, minor depolarization on the mitochondrial membrane, moderate depolarization of plasma membrane, and no changes in NAD(P)H and ATP. The response is linked to the influx of extracellular Na+ and the subsequent activation of mitochondrial Na+/Ca2+ and Na+/H+ exchange. The mitochondrial Na+/Ca2+ exchanger ((m)NCX) activated by Na+ influx reduces Ca2+ and increases Na+ levels in the mitochondrial matrix. The excess of Na+ activates the mitochondrial Na+/H+ exchanger (NHE) increasing the outward pumping of protons, electron transport and O2 consumption. Reduction in extracellular Na+ and inhibition of Na+ influx through the receptor operated calcium channels and plasmalemmal NHE reduce the respiratory response. Inhibition of the (m)NCX, L-type voltage gated Ca2+ channels or the release of Ca2+ from the endoplasmic reticulum also reduces the respiratory spike, indicating that unimpaired intercompartmental Ca2+ exchange is critical for response development.
Collections Ireland -> University College Cork -> PubMed

Full list of authors on original publication

Dmitri B Papkovsky, Jochen H M Prehn, Dmitri M Chudakov, Ekaterina A Souslova, Cormac T. Taylor, Manus W Ward, Alexander V Zhdanov

Experts in our system

Dmitri B Papkovsky
University College Cork
Total Publications: 89
Jochen H M Prehn
Royal College of Surgeons in Ireland
Total Publications: 206
Cormac T. Taylor
University College Dublin
Total Publications: 110
Alexander V Zhdanov
University College Cork
Total Publications: 37