title: Neuronal NO promotes cerebral cortical hyperemia during cortical spreading depression in rabbits.
abstract: Temporary elevations in cortical cerebral blood flow (CBF) accompany cortical spreading depression (CSD) in anesthetized animals. We tested the hypothesis that nitric oxide (NO) is an important promotor of CSD-induced cortical hyperemia in urethan-anesthetized rabbits. CBF was measured at four time points by administration of 15-microm microspheres with the reference withdrawal technique. Intravenous administration of the nonspecific NO synthase (NOS) inhibitor N(omega)-nitro-L-arginine increased mean arterial blood pressure and resting cerebrovascular resistance and attenuated CSD-induced hyperemia. Cortical CBF before intraperitoneal 7-nitroindazole (7-NI), a neuronal NOS inhibitor, was 42 +/- 8 and 124 +/- 19 ml x 100 g(-1) x min(-1) at baseline and during CSD, respectively (P < 0.05 by repeated-measures analysis of variance). After 7-NI administration, mean arterial blood pressure, CBF, and cerebrovascular resistance were unchanged from baseline values; cortical CBF was 38 +/- 4 and 90 +/- 8 ml x 100 g(-1) x min(-1) post-7-NI at rest and during a second CSD, respectively. Similar to N(omega)-nitro-L-arginine, 7-NI decreased the cortical hyperemic response during CSD (P < 0.05 by repeated-measures analysis of variance). We conclude that neuronal NOS promotes the temporary cortical hyperemia observed during CSD.
authors.affiliation: Department of Anesthesia, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27157-1009, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Colonna
authors.forename: W
authors.initials: W
authors.lastname: Meng
authors.forename: D D
authors.initials: DD
authors.lastname: Deal
authors.forename: M
authors.initials: M
authors.lastname: Gowda
authors.forename: D W
authors.initials: DW
authors.lastname: Busija
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000098:blood supply*; D002245:Carbon Dioxide / Q000097:blood; D002540:Cerebral Cortex / Q000098:blood supply* / Q000502:physiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D013181:Cortical Spreading Depression; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006940:Hyperemia / Q000503:physiopathology*; D008863:Microspheres; D009474:Neurons / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology*; D009928:Organ Specificity; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011817:Rabbits; D012039:Regional Blood Flow; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D006454:Hemoglobins; D002245:Carbon Dioxide; D019335:Nitroarginine; D009569:Nitric Oxide; D010100:Oxygen