title: Formaldehyde inhalation reduces respiratory mechanics in a rat model with allergic lung inflammation by altering the nitric oxide/cyclooxygenase-derived products relationship.
abstract: Bronchial hyperresponsiveness is a hallmark of asthma and many factors modulate bronchoconstriction episodes. A potential correlation of formaldehyde (FA) inhalation and asthma has been observed; however, the exact role of FA remains controversial. We investigated the effects of FA inhalation on Ovalbumin (OVA) sensitisation using a parameter of respiratory mechanics. The involvement of nitric oxide (NO) and cyclooxygenase-derived products were also evaluated. The rats were submitted, or not, to FA inhalation (1%, 90 min/day, 3 days) and were OVA-sensitised and challenged 14 days later. Our data showed that previous FA exposure in allergic rats reduced bronchial responsiveness, respiratory resistance (Rrs) and elastance (Ers) to methacholine. FA exposure in allergic rats also increased the iNOS gene expression and reduced COX-1. L-NAME treatment exacerbated the bronchial hyporesponsiveness and did not modify the Ers and Rrs, while Indomethacin partially reversed all of the parameters studied. The L-NAME and Indomethacin treatments reduced leukotriene B₄ levels while they increased thromboxane B₂ and prostaglandin E₂. In conclusion, FA exposure prior to OVA sensitisation reduces the respiratory mechanics and the interaction of NO and PGE₂ may be representing a compensatory mechanism in order to protect the lung from bronchoconstriction effects.
authors.affiliation: Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil. adrilino@usp.br
authors.forename: Adriana
authors.initials: A
authors.lastname: Lino-dos-Santos-Franco
authors.forename: João Antonio
authors.initials: JA
authors.lastname: Gimenes-Júnior
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Ligeiro-de-Oliveira
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Breithaupt-Faloppa
authors.forename: Beatriz Golegã
authors.initials: BG
authors.lastname: Acceturi
authors.forename: Luana Beatriz
authors.initials: LB
authors.lastname: Vitoretti
authors.forename: Isabel Daufenback
authors.initials: ID
authors.lastname: Machado
authors.forename: Ricardo Martins
authors.initials: RM
authors.lastname: Oliveira-Filho
authors.forename: Sandra Helena Poliselli
authors.initials: SH
authors.lastname: Farsky
authors.forename: Henrique Takachi
authors.initials: HT
authors.lastname: Moriya
authors.forename: Wothan
authors.initials: W
authors.lastname: Tavares-de-Lima
mesh_terms: D000280:Administration, Inhalation; D000403:Airway Resistance / Q000187:drug effects; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D016535:Bronchial Hyperreactivity / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D051545:Cyclooxygenase 1 / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000819:agonists / Q000378:metabolism; D004195:Disease Models, Animal; D015777:Eicosanoids / Q000378:metabolism*; D005557:Formaldehyde / Q000008:administration & dosage / Q000633:toxicity; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007975:Leukotriene B4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012131:Respiratory Insufficiency / Q000209:etiology / Q000517:prevention & control*; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D013929:Thromboxane B2 / Q000819:agonists / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016085:Bronchoconstrictor Agents; D015777:Eicosanoids; D008565:Membrane Proteins; D005557:Formaldehyde; D007975:Leukotriene B4; D009569:Nitric Oxide; D013929:Thromboxane B2; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051545:Cyclooxygenase 1; C496513:Ptgs1 protein, rat; D015232:Dinoprostone
keywords: Allergic lung disease; Bronchial responsiveness; Cyclooxygenase products; Nitric oxide; Pollution; Pulmonary mechanics