title: Inhibiting NADPH oxidase protects against long-term memory impairment induced by neonatal sevoflurane exposure in mice.
abstract: Neonatal exposure to anaesthetics such as sevoflurane has been reported to result in behavioural deficits in rodents. However, while oxidative injury is thought to play an underlying pathological role, the mechanisms of neurotoxicity remain unclear. In the present study, we investigated whether the NADPH oxidase inhibitor apocynin protects against long-term memory impairment produced by neonatal sevoflurane exposure in mice.
  
  
  
  Postnatal day six mice were divided into four groups; (1) non-anaesthesia, (2) intraperitoneal apocynin (50 mg kg(-1)) treatment, (3) 3% sevoflurane exposure for 6 h, and (4) apocynin treatment combined with sevoflurane exposure. Superoxide concentrations and NADPH oxidase expression in the brain were determined using dihydroethidium fluorescence and immunoblotting, respectively. Cleaved caspase-3 immunoblotting was used for the detection of apoptosis, and cytochrome c immunoblotting was performed to evaluate mitochondrial function. Long-term cognitive impairment was evaluated using the fear conditioning test in adulthood.
  
  
  
  Sevoflurane exposure increased concentrations of superoxide (109%) and the NADPH oxidase subunit p22phox (39%) in the brain, and apocynin abolished these increases. Neonatal sevoflurane exposure caused learning deficits in adulthood. Apocynin also maintained long-term memory function in mice given neonatal sevoflurane exposure, and it reduced apoptosis and decreased cytochrome c concentrations in the brains of these mice.
  
  
  
  Apocynin reduces neuronal apoptosis and protects against long-term memory impairment in mice, neonatally exposed to sevoflurane by reducing superoxide concentrations. These findings suggest that NADPH oxidase inhibitors may protect against cognitive dysfunction resulting from neonatal anaesthesia.
authors.affiliation: Department of Anaesthesiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Z
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Anaesthesiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan satomoto.mane@tmd.ac.jp.
authors.forename: M
authors.initials: M
authors.lastname: Satomoto
authors.affiliation: Department of Anaesthesiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Y U
authors.initials: YU
authors.lastname: Adachi
authors.affiliation: Department of Anaesthesiology, Aichi Medical University School of Medicine, Aichi, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kinoshita
authors.affiliation: Department of Anaesthesiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Makita
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D057567:Memory, Long-Term; D008738:Methyl Ethers; D051379:Mice; D008810:Mice, Inbred C57BL; D019255:NADPH Oxidases; D000077149:Sevoflurane
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane; D019255:NADPH Oxidases
keywords: anaesthesia; anaesthetics; brain; neurotoxicity; paediatric; sevoflurane