title: Chemical preconditioning in mice is not mediated by upregulation of nitric oxide synthase isoforms.
abstract: Ischemic preconditioning requires increased nitric oxide (NO) production. However, NO may also trigger delayed neuronal death cascades. The goal therefore was to investigate nitric oxide synthase (NOS) isoforms (neuronal NOS: nNOS; endothelial NOS: eNOS; inducible NOS: iNOS) with reverse transcriptase-polymerase chain reaction in hippocampal slices from control mice and slices prepared upon preconditioning in vivo (single intraperitoneal injection of 20 mg/kg body weight 3-nitropropionate (3NP)). One hour after preconditioning nNOS (108+/-34%, mean+/-SD), eNOS (93+/-34%), and iNOS (282+/-261%) remained at control levels. Similarly, nNos, eNOS, and iNOS stayed at control level 12, 24, and 72 h after preconditioning with 3NP. Incubation of slices, however, drastically increased iNOS (1676+/-818, P<0.01). We conclude that chemical preconditioning other than ischemic preconditioning may not increase potentially harmful nitric oxide synthase isoforms.
authors.affiliation: Department of Neurology, University of Ulm, Steinhövelstrasse 1, 89075 Ulm, Germany.
authors.forename: C A
authors.initials: CA
authors.lastname: von Arnim
authors.forename: M
authors.initials: M
authors.lastname: Timmler
authors.forename: A C
authors.initials: AC
authors.lastname: Ludolph
authors.forename: M W
authors.initials: MW
authors.lastname: Riepe
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D002545:Brain Ischemia / Q000201:enzymology* / Q000503:physiopathology; D002490:Central Nervous System / Q000201:enzymology* / Q000503:physiopathology; D006624:Hippocampus / Q000201:enzymology / Q000503:physiopathology; D019194:Ischemic Preconditioning; D008297:Male; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics*; D009574:Nitro Compounds; D009924:Organ Culture Techniques; D011422:Propionates / Q000494:pharmacology; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology*
chemical_list: D000959:Antihypertensive Agents; D009574:Nitro Compounds; D011422:Propionates; D020033:Protein Isoforms; D012333:RNA, Messenger; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C015392:3-nitropropionic acid