7-Nitroindazole reduces nitric oxide concentration in rat hippocampus after transient forebrain ischemia.
We investigated the effects of 7-nitroindazole, a specific inhibitor of neuronal nitric oxide (NO) synthase, on NO concentration and on blood flow in rat hippocampus after transient forebrain ischemia which was induced by 4-vessel occlusion for 10 min. NO concentration was measured directly by an NO-selective electrode method. Hippocampal blood flow was also estimated by laser Doppler flowmetry. 7-Nitroindazole [0 (vehicle), 12.5, 25, 50 or 100 mg/kg] was administered intraperitoneally 20 min before ischemia. 7-Nitroindazole at any dose used did not affect basal NO levels before ischemia. 7-Nitroindazole (25, 50 and 100 mg/kg) reduced the NO concentration significantly during post-ischemic early reperfusion. Before 10 min of ischemia and during post-ischemic early reperfusion, there were no significant differences in hippocampal basal blood flow and reactive hyperemia between vehicle- and 7-nitroindazole-treated groups. These results demonstrate that the neuronal NO synthase inhibitor, 7-nitroindazole, can effectively inhibit NO synthesis in rat hippocampus during post-ischemic early reperfusion.
Jiang
M H
MH
Department of Physiology, Hyogo College of Medicine, Nishinomiya, Japan.
Kaku
T
T
Hada
J
J
Hayashi
Y
Y
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006624:Hippocampus / Q000098:blood supply / Q000187:drug effects* / Q000378:metabolism; D006940:Hyperemia / Q000139:chemically induced / Q000517:prevention & control; D007191:Indazoles / Q000494:pharmacology*; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D016548:Prosencephalon / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects; D015427:Reperfusion Injury / Q000517:prevention & control
D004791:Enzyme Inhibitors; D007191:Indazoles; D009569:Nitric Oxide; C080122:7-nitroindazole