Nitric oxide promotes seizure activity in kainate-treated rats.
L-Arginine-derived nitrogen monoxide (NO) formation was determined in different regions of the rat brain during kainate-induced seizures. NO was trapped in vivo as a paramagnetic mononitrosyl-iron diethyldithiocarbamate complex, the concentration of which was determined ex vivo by cryogenic electron spin resonance spectroscopy. Basal NO formation (0.3-0.8 nmol g-1 tissue 30 min-1) was detected in the brain of control rats. In kainate-injected rats NO formation was increased six-fold within 30-60 min in the amygdala/temporal cortex region, and up to 12-fold, though more slowly, in the remaining cortex. The kainate-elicited convulsions and NO formation were attenuated in animals pretreated with either 7-nitroindazole, a specific inhibitor of neuronal NO synthase, or diazepam. These findings identify NO as a proconvulsant mediator in kainate-evoked seizures.
Mülsch
A
A
Zentrum der Physiologie, Universität Frankfurt, Germany.
Busse
R
R
Mordvintcev
P I
PI
Vanin
A F
AF
Nielsen
E O
EO
Scheel-Krüger
J
J
Olesen
S P
SP
D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D003975:Diazepam / Q000378:metabolism / Q000494:pharmacology; D004050:Ditiocarb / Q000494:pharmacology; D007191:Indazoles / Q000494:pharmacology; D007501:Iron / Q000378:metabolism; D007608:Kainic Acid; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced* / Q000378:metabolism* / Q000503:physiopathology
D007191:Indazoles; D009569:Nitric Oxide; D004050:Ditiocarb; D007501:Iron; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D003975:Diazepam; D007608:Kainic Acid; C080122:7-nitroindazole