Nasal allergy-like symptoms aggravated by ozone exposure in a concentration-dependent manner in guinea pigs.
Our previous study revealed that exposure to 0.4 ppm ozone (O(3)) enhanced nasal allergy-like reactions in guinea pigs. In the present study, we investigated the concentration-dependency of the effects of exposure to O(3) on the aggravation of nasal allergy-like reactions induced by repeated nasal administration of antigen. Guinea pigs were exposed to filtered air or 0.1-0.6 ppm O(3) for 5 weeks. After each weekly administration of ovalbumin (OVA), sneezes and nasal secretions were measured. The number of eosinophils infiltrating the nasal septum and the titers of OVA-specific antibody were measured 24h after the last administration. Ozone increased sneezing and nasal secretion induced by OVA, nasal responsiveness to physical stimuli, and the number of infiltrating eosinophils in a concentration-dependent manner. The titer of anti-OVA-IgG was increased in animals exposed to 0.6 ppm O(3). Thus, exposure to O(3) aggravated nasal allergy-like symptoms concentration dependently. The aggravation was caused by induction of nasal hyperresponsiveness, the infiltration of eosinophils, and the increase in the production of anti-OVA-IgG. The estimated maximum likelihood estimation concentrations (MLECs) and bench mark concentrations (BMCs) of O(3) for these indices were in the range of 0.09-0.18 and 0.02-0.06 ppm, respectively.
Iijima
Mariko K
MK
Department of Medicine, Tsukuba University, Tsukuba 305-8575, Japan.
Kobayashi
Takahiro
T
D000280:Administration, Inhalation; D000818:Animals; D019985:Benchmarking; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000187:drug effects / Q000473:pathology; D006168:Guinea Pigs; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D009297:Nasal Mucosa / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D010047:Ovalbumin / Q000276:immunology; D010083:Oxidants, Photochemical / Q000008:administration & dosage / Q000633:toxicity*; D010126:Ozone / Q000008:administration & dosage / Q000633:toxicity*; D012221:Rhinitis, Allergic, Perennial / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D012912:Sneezing / Q000187:drug effects
D007074:Immunoglobulin G; D010083:Oxidants, Photochemical; D010126:Ozone; D010047:Ovalbumin