Tolerance to lipopolysaccharide is related to the nitric oxide pathway.
Repeated administration of lipopolysaccharide (LPS) induces a refractory state to its usual pyrogenic effects which is called endotoxin tolerance. We tested the hypothesis that nitric oxide (NO) participates in the endotoxin tolerance. Single injection of LPS resulted in an elevation in body temperature (Tb), whereas a significant reduction of the thermoregulatory response to LPS was observed to repeated administration of LPS (administered at 48 h intervals). Intracerebroventricular (i.c.v.) injection of L-NAME (a non-selective NO inhibitor of nitric oxide synthesis) markedly enhanced the febrile response to LPS in tolerant rats. The data suggest that NO pathway in the central nervous system plays a role in endotoxin tolerance.
Almeida
M C
MC
Faculdade de Odontologia de Ribeirao Preto, Universidade de Sao Paulo, Brasil.
Trevisan
F N
FN
Barros
R C
RC
Carnio
E C
EC
Branco
L G
LG
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001831:Body Temperature / Q000187:drug effects; D004361:Drug Tolerance; D004768:Enterotoxins / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005334:Fever / Q000139:chemically induced / Q000503:physiopathology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052248:Nitric Oxide Synthase Type I; D051381:Rats; D017208:Rats, Wistar
D001427:Bacterial Toxins; D004768:Enterotoxins; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D009569:Nitric Oxide; C027538:heat-labile enterotoxin, E coli; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D019331:NG-Nitroarginine Methyl Ester