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Document 0177
DOCN M9630177
TI [Does nitric oxide stress exist?]
DT 9603
AU Torreilles J; Guerin MC; INSERM U58, Montpellier.
SO C R Seances Soc Biol Fil. 1995;189(3):389-400. Unique Identifier :
AIDSLINE MED/96098961
AB Ten years ago, the term oxidative stress (sigma -O2) was created to
define oxidative damage inflicted to the organism. This definition
brings together processes involving reactive oxygen species production
and action such as free radical production during univalent reduction of
oxygen within mitochondria, activation of NADPH-dependent oxidase system
on the membrane surface of neutrophils, flavoprotein-catalyzed redox
cycling of xenobiotics and exposure to chemical and physical agents in
the environment. Since the discovery of the nitric oxide biosynthetic
pathway, the deleterious effects of uncontrolled nitric oxide generation
are generally classified as oxidative stress. Indeed, products of the
reaction of NO and superoxide lead to oxidants such as peroxinitrite,
nitrogen dioxide and hydroxyl radical, which are involved in mechanisms
of cell-mediated immune reactions and defence of the intracellular
environment against microbiol invasion. However NO can also regulate
many biological reactions and signal transduction pathways that lead to
a variety of physiological responses such as blood pressure,
neurotransmission, platelet aggregation, endothelin generation or smooth
muscle cell proliferation. Then the uncontrolled NO production can lead
to a variety of physiological and pathophysiological responses similar
to a Nitric Oxide Stress: activation of guanylate cyclase and production
of cGMP: overstimulation of the inducible L-arginine to L-citrulline and
NO pathway by bactericidal endotoxins and cytokines has been shown to
promote undesired increases in vasodilatation, which may account for
hypotension in septic shock and cytokine therapy. stimulation of
auto-ADP-ribosylation and modification of SH-groups of
glyceraldehyde-3-phosphate dehydrogenase in a cGMP-independent
mechanism: by this way, NO in excess can strongly inhibits this
important glycolytic enzyme and reduce the cellular energy production.
inhibition of ribonucleotide reductase: extensive inhibition of this key
enzyme in DNA synthesis in the presence of large amounts of NO could
lead to important antiproliferative effects; inhibition of cytochrome
P450-dependent metabolism: in Kupffer cells and hepatocytes, LPS-induced
overproduction of NO has been shown to inhibit cytochrome P450-dependent
metabolism and to mediate the suppression of hepatic metabolism.
Moreover, NO synthetized in the peripheral nervous system is known to
mediate nonadrenergic noncholinergic (NANC) neurotransmission.
Overstimulation of NO synthases might therefore contribute to
pathophysiological states such as: gastrointestinal motility, reflux
oesophagitis, asthma, adult respiratory distress syndrome (ARDS) and
chronic pulmonary artery hypertension. To these NO-mediated biological
functions, one could add the biological effects of NO-derivatives such
as N-nitrosocompounds, which act as carcinogenic agents, or
C-nitrosocompound which were recently used as zinc-ejecting agents to
inhibit HIV-1 infectivity of human T-lymphocytes.(ABSTRACT TRUNCATED AT
400 WORDS)
DE English Abstract Free Radicals/METABOLISM Hemeproteins/METABOLISM In
Vitro Nitric Oxide/*METABOLISM Oxidation-Reduction *Oxidative Stress
JOURNAL ARTICLE REVIEW REVIEW, TUTORIAL
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).