Cerebral blood flow changes during cortical spreading depression are not altered by inhibition of nitric oxide synthesis.
CBF increases concomitantly with cortical spreading depression (CSD). We tested the hypothesis that CBF changes during CSD are mediated by nitric oxide (NO). Male Wistar rats (n = 23) were subjected to KCl-induced CSD before and after administration of nitric oxide synthase (NOS) inhibitors N-nitro-L-arginine (L-NNA) or N-nitro-L-arginine methyl ester (L-NAME) and in nontreated animals. CBF, CSD, and mean arterial blood pressure were recorded. Brain NOS activity was measured in vitro in control, L-NNA, and L-NAME-treated rats by the conversion of [3H]arginine to [3H]citrulline. Our data show that the NOS inhibitors did not significantly change regional CBF (rCBF) during CSD, even though cortical NOS activity was profoundly depressed and systemic arterial blood pressure was significantly increased. Our data suggest that rCBF during CSD in rats is not regulated by NO.
Zhang
Z G
ZG
Department of Neurology, Henry Ford Health Science System, Detroit, MI 48202.
Chopp
M
M
Maynard
K I
KI
Moskowitz
M A
MA
D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D002540:Cerebral Cortex / Q000201:enzymology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D013181:Cortical Spreading Depression / Q000502:physiology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D051381:Rats; D017208:Rats, Wistar
D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D019331:NG-Nitroarginine Methyl Ester