title: Involvement of neuronal nitric oxide synthase in ongoing fetal brain injury following near-term rabbit hypoxia-ischemia.
abstract: Neuronal nitric oxide synthase (nNOS) and nitric oxide (NO) are implicated in neuronal injury following acute hypoxia-ischemia (HI). Our hypothesis was that NO from nNOS is responsible for ongoing mitochondrial dysfunction in near-term fetal HI. Recently, we synthesized new selective nNOS inhibitors that prevent the cerebral palsy phenotype in our animal model. We tested the efficacy of a selective nNOS inhibitor (JI-8) in fetal brains after in utero HI in our rabbit model. Brain slices at 29 days gestation were obtained after in utero HI, and immediately cultured in medium containing JI-8 or saline for 3-6 days. Mitochondrial membrane integrity and function were determined by flow cytometry using rhodamine 123 and JC-1, and cell death by using propidium iodide. JI-8 decreased NO production in brain slices and also showed significant preservation of mitochondrial function at both 3 and 6 days (p < 0.05) when compared with saline and inducible NOS inhibitor 1400W. There was no difference in cell death. In conclusion, nNOS is involved in ongoing mitochondrial dysfunction after in utero HI. The subacute brain slice model could be a tool for studying the mechanisms involved in ongoing neuronal injury, and for rapidly assessing potential neuroprotectants.
authors.affiliation: Department of Pediatrics, Northwestern University, Chicago, IL, USA.
authors.forename: Suma
authors.initials: S
authors.lastname: Rao
authors.forename: Zhenlang
authors.initials: Z
authors.lastname: Lin
authors.forename: Alexander
authors.initials: A
authors.lastname: Drobyshevsky
authors.forename: Lina
authors.initials: L
authors.lastname: Chen
authors.forename: Xinhai
authors.initials: X
authors.lastname: Ji
authors.forename: Haitao
authors.initials: H
authors.lastname: Ji
authors.forename: Yirong
authors.initials: Y
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.forename: Matthew
authors.initials: M
authors.lastname: Derrick
authors.forename: Richard B
authors.initials: RB
authors.lastname: Silverman
authors.forename: Sidhartha
authors.initials: S
authors.lastname: Tan
mesh_terms: D000818:Animals; D001930:Brain Injuries / Q000201:enzymology* / Q000473:pathology*; D005260:Female; D005333:Fetus / Q000201:enzymology* / Q000473:pathology*; D020925:Hypoxia-Ischemia, Brain / Q000201:enzymology* / Q000473:pathology*; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D011247:Pregnancy; D011817:Rabbits
chemical_list: D009569:Nitric Oxide; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II