Dynamic and interacting profiles of *NO and O2 in rat hippocampal slices.
Nitric oxide (*NO) is a ubiquitous signaling molecule that participates in the neuromolecular phenomena associated with memory formation. In the hippocampus, neuronal *NO production is coupled to the activation of the NMDA-type of glutamate receptor. Although *NO-mediated signaling has been associated with soluble guanylate cyclase activation, cytochrome oxidase is also a target for this gaseous free radical, for which *NO competes with O(2). Here we show, for the first time in a model preserving tissue cytoarchitecture (rat hippocampal slices) and at a physiological O(2) concentration, that endogenous NMDA-evoked *NO production inhibits tissue O(2) consumption for submicromolar concentrations. The simultaneous real-time recordings reveal a direct correlation between the profiles of *NO and O(2) in the CA1 subregion of the hippocampal slice. These results, obtained in a system close to in vivo models, strongly support the current paradigm for O(2) and *NO interplay in the regulation of cellular respiration.
Ledo
Ana
A
Center for Neurosciences and Cell Biology, University of Coimbra, 3000 Coimbra, Portugal.
Barbosa
Rui
R
Cadenas
Enrique
E
Laranjinha
João
J
D000818:Animals; D003486:Cyanides / Q000494:pharmacology; D006624:Hippocampus / Q000378:metabolism*; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism
C106731:3-bromo-7-nitroindazole; D003486:Cyanides; D007191:Indazoles; D016194:Receptors, N-Methyl-D-Aspartate; D009569:Nitric Oxide; D016202:N-Methylaspartate; D019001:Nitric Oxide Synthase; D010100:Oxygen