Effects of a neuronal nitric oxide synthase inhibitor on lipopolysaccharide-induced fever
Braz. j. med. biol. res
;
32(11): 1381-7, Nov. 1999. graf
Article
in English
| LILACS
| ID: lil-248432
RESUMO
It has been demonstrated that nitric oxide (NO) has a thermoregulatory action, but very little is known about the mechanisms involved. In the present study we determined the effect of neuronal nitric oxide synthase (nNOS) inhibition on thermoregulation. We used 7-nitroindazole (7-NI, 1, 10 and 30 mg/kg body weight), a selective nNOS inhibitor, injected intraperitoneally into normothermic Wistar rats (200-250 g) and rats with fever induced by lipopolysaccharide (LPS) (100 µg/kg body weight) administration. It has been demonstrated that the effects of 30 mg/kg of 7-NI given intraperitoneally may inhibit 60 per cent of nNOS activity in rats. In all experiments the colonic temperature of awake unrestrained rats was measured over a period of 5 h at 15-min intervals after intraperitoneal injection of 7-NI. We observed that the injection of 30 mg/kg of 7-NI induced a 1.5oC drop in body temperature, which was statistically significant 1 h after injection (P<0.02). The coinjection of LPS and 7-NI was followed by a significant (P<0.02) hypothermia about 0.5oC below baseline. These findings show that an nNOS isoform is required for thermoregulation and participates in the production of fever in rats.
Full text:
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Index:
LILACS (Americas)
Main subject:
Body Temperature Regulation
/
Lipopolysaccharides
/
Nitric Oxide Synthase
/
Enzyme Inhibitors
/
Fever
/
Indazoles
/
Neurons
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
1999
Type:
Article
/
Congress and conference
Affiliation country:
Brazil
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