title: Functional importance of neuronal nitric oxide synthase in the endothelium of rat basilar arteries.
abstract: The function of the neuronal isoform of nitric oxide synthase (nNOS) was studied by comparing the effects of the specific nNOS blocker 7-nitro indazole monosodium salt (7-NINA) with that of the general NOS inhibitor N(G)-nitro-L-arginine (L-NA) in isolated rat basilar arteries (BAs). 7-NINA had no significant effect on the resting tone of the vessels, while both L-NA and 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one (ODQ), a selective inhibitor of the soluble guanylyl cyclase, induced contraction. The relaxant effect of bradykinin was attenuated in the presence of L-NA but was not changed by 7-NINA. In contrast, 7-NINA markedly reduced the acetylcholine-induced, endothelium-dependent relaxation. These results demonstrate that nNOS contributes significantly to the relaxant effect of acetylcholine, indicating the functional importance of this isoenzyme in the cerebrovascular endothelium.
authors.affiliation: Department of Physiology, Ludwig-Maximilians University, Munich, Germany. benyo@elet2.sote.hu
authors.forename: Z
authors.initials: Z
authors.lastname: Benyó
authors.forename: Z
authors.initials: Z
authors.lastname: Lacza
authors.forename: T
authors.initials: T
authors.lastname: Hortobágyi
authors.forename: C
authors.initials: C
authors.lastname: Görlach
authors.forename: M
authors.initials: M
authors.lastname: Wahl
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000378:metabolism*; D001920:Bradykinin / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D019001:Nitric Oxide Synthase / Q000187:drug effects / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D051381:Rats; D017208:Rats, Wistar; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D000109:Acetylcholine; D001920:Bradykinin