Antigen Sensitization Influences Organophosphorus Pesticide–Induced Airway Hyperreactivity

• DOI: 10.1289/ehp.10694
• Publication Date: 2008-01-02T19:10:43Z
• Authors: Becky J. Proskocil; Donald A. Bruun; Jesse K. Lorton; Kirsten C. Blensly; David B. Jacoby; Pamela J. Lein; Allison D. Fryer
• Keywords: Parathion

BackgroundRecent epidemiologic studies have identified organophosphorus pesticides (OPs) as environmental factors potentially contributing to the increase in asthma prevalence over last 25 years. In support of this hypothesis, we demonstrated that environmentally relevant concentrations OPs induce airway hyperreactivity guinea pigs.ObjectivesSensitization allergen is a significant factor asthma, and shown sensitization changes virus-induced from an eosinophil-independent mechanism one mediated by eosinophils. Here, determine whether similarly influences OP-induced hyperreactivity.MethodsNonsensitized ovalbumin-sensitized pigs were injected subcutaneously with OP parathion (0.001–1.0 mg/kg). Twenty-four hours later, animals anesthetized ventilated, bronchoconstriction was measured response either vagal stimulation or intravenous acetylcholine. Inflammatory cells acetylcholinesterase activity assessed tissues collected immediately after physiologic measurements.ResultsOvalbumin decreased threshold dose for parathion-induced exacerbated effects on vagally induced bronchoconstriction. Pretreatment antibody interleukin (IL)-5 prevented sensitized but not nonsensitized pigs. Parathion did number eosinophils airways associated nerves nor it alter eosinophil activation major basic protein deposition.ConclusionsAntigen increases vulnerability dependent IL-5. Because allergens characteristic 50% general population 80% asthmatics (including children), these findings implications risk assessment, intervention, treatment strategies.