Measurement of nitric oxide in the rat cerebral cortex during hypercapnoea.
Changes in nitric oxide (NO) concentration and cerebral blood flow (CBF) in the parietal cortex during hypercapnoea were investigated in anaesthetized rats, using a NO-selective electrode and laser Doppler flowmetry. When hypercapnoea was induced by inhalation of 5% CO2 for 10 min, both the NO concentration and CBF increased. After administration of 7-nitroindazole, a neuronal NO synthase (nNOS) inhibitor, both the basal NO and CBF decreased, and responses to hypercapnoea were also significantly suppressed by 70.1% and 73.2%, respectively, compared with the control state. These results suggest that NO derived from nNOS is involved not only in maintaining resting cerebral circulation but also in regulating CBF response during hypercapnoea.
Harada
M
M
Department of Anesthesiology, Kyoto Prefectural University of Medicine, Japan.
Fuse
A
A
Tanaka
Y
Y
D000818:Animals; D002245:Carbon Dioxide / Q000097:blood*; D002540:Cerebral Cortex / Q000098:blood supply* / Q000378:metabolism*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006935:Hypercapnia / Q000378:metabolism / Q000503:physiopathology; D007191:Indazoles / Q000494:pharmacology; D017078:Laser-Doppler Flowmetry; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects
D004791:Enzyme Inhibitors; D007191:Indazoles; D002245:Carbon Dioxide; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C080122:7-nitroindazole