PMID- 17164295
OWN - NLM
STAT- MEDLINE
DCOM- 20070404
LR  - 20131121
IS  - 0021-9533 (Print)
IS  - 0021-9533 (Linking)
VI  - 120
IP  - Pt 1
DP  - 2007 Jan 1
TI  - Cytochrome c oxidase maintains mitochondrial respiration during partial 
      inhibition by nitric oxide.
PG  - 160-5
AB  - Nitric oxide (NO), generated endogenously in NO-synthase-transfected cells, 
      increases the reduction of mitochondrial cytochrome c oxidase (CcO) at O2 
      concentrations ([O2]) above those at which it inhibits cell respiration. Thus, in 
      cells respiring to anoxia, the addition of 2.5 microM L-arginine at 70 microM O2 
      resulted in reduction of CcO and inhibition of respiration at [O2] of 64.0+/-0.8 
      and 24.8+/-0.8 microM, respectively. This separation of the two effects of NO is 
      related to electron turnover of the enzyme, because the addition of electron 
      donors resulted in inhibition of respiration at progressively higher [O2], and to 
      their eventual convergence. Our results indicate that partial inhibition of CcO 
      by NO leads to an accumulation of reduced cytochrome c and, consequently, to an 
      increase in electron flux through the enzyme population not inhibited by NO. 
      Thus, respiration is maintained without compromising the bioenergetic status of 
      the cell. We suggest that this is a physiological mechanism regulated by the flux 
      of electrons in the mitochondria and by the changing ratio of O2:NO, either 
      during hypoxia or, as a consequence of increases in NO, as a result of cell 
      stress.
FAU - Palacios-Callender, Miriam
AU  - Palacios-Callender M
AD  - Wolfson Institute for Biomedical Research, University College London, Cruciform 
      Building, Gower Street, London, WC1E 6BT, UK.
FAU - Hollis, Veronica
AU  - Hollis V
FAU - Frakich, Nanci
AU  - Frakich N
FAU - Mateo, Jesus
AU  - Mateo J
FAU - Moncada, Salvador
AU  - Moncada S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20061212
PL  - England
TA  - J Cell Sci
JT  - Journal of cell science
JID - 0052457
RN  - 0 (Cytochrome c Group)
RN  - 0 (Cytochromes a3)
RN  - 0 (cytochrome caa(3))
RN  - 31C4KY9ESH (Nitric Oxide)
RN  - 9035-34-1 (Cytochromes a)
RN  - 94ZLA3W45F (Arginine)
RN  - EC 1.14.13.39 (Nitric Oxide Synthase)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Arginine/metabolism/pharmacology
MH  - Cell Hypoxia/*physiology
MH  - Cell Line
MH  - Cell Respiration/drug effects/physiology
MH  - Cytochrome c Group/metabolism
MH  - Cytochromes a/metabolism
MH  - Cytochromes a3/metabolism
MH  - Electron Transport/physiology
MH  - Electron Transport Complex IV/*metabolism
MH  - Humans
MH  - Mitochondria/*enzymology
MH  - Nitric Oxide/*metabolism
MH  - Nitric Oxide Synthase/genetics/metabolism
MH  - Oxygen/metabolism
MH  - Oxygen Consumption/drug effects/physiology
MH  - Transfection
EDAT- 2006/12/14 09:00
MHDA- 2007/04/05 09:00
CRDT- 2006/12/14 09:00
PHST- 2006/12/14 09:00 [pubmed]
PHST- 2007/04/05 09:00 [medline]
PHST- 2006/12/14 09:00 [entrez]
AID - jcs.03308 [pii]
AID - 10.1242/jcs.03308 [doi]
PST - ppublish
SO  - J Cell Sci. 2007 Jan 1;120(Pt 1):160-5. doi: 10.1242/jcs.03308. Epub 2006 Dec 12.