Nitric oxide does not inhibit cerebral cytochrome oxidase in vivo or in the reactive hyperemic phase after brief anoxia in the adult rat.
In this study, near-infrared spectroscopy was applied to examine whether cytochrome oxidase in the rat brain is inhibited by nitric oxide in vivo. During normoxia, intravenous N(G)-nitro-L-arginine methyl ester (L-NAME) administration significantly decreased the cerebral saturation of hemoglobin with oxygen but did not alter the cytochrome oxidase redox state. Anoxia significantly reduced the cytochrome oxidase. The time course of the recovery of the redox state during reoxygenation was not altered by L-NAME. The results suggest that in adult rats, cytochrome oxidase is not inhibited by nitric oxide, either in physiologic conditions or during reoxygenation after a brief anoxic period.
De Visscher
Geofrey
G
Department of Neuropathology, Discovery Research, Janssen Research Foundation, Turnhoutseweg 30, B-2340 Beerse, Belgium. gdvissch@janbe.jnj.com
Springett
Roger
R
Delpy
David T
DT
Van Reempts
Jos
J
Borgers
Marcel
M
van Rossem
Koen
K
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000201:enzymology*; D003576:Electron Transport Complex IV / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006454:Hemoglobins / Q000378:metabolism; D006940:Hyperemia / Q000201:enzymology*; D002534:Hypoxia, Brain / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010084:Oxidation-Reduction; D010100:Oxygen / Q000097:blood; D010108:Oxyhemoglobins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D019265:Spectroscopy, Near-Infrared
D004791:Enzyme Inhibitors; D006454:Hemoglobins; D010108:Oxyhemoglobins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D003576:Electron Transport Complex IV; D010100:Oxygen; D019331:NG-Nitroarginine Methyl Ester