Objective:The aim of this study is to the roles of nasal lavage fluid levels of MUC5 AC,goblet cell hyperplasia and ultrastructure of nasal mucosa following ambient PM 2.5 exposure in a rat model of allergic rhinitis(AR).Method:Female Sprague-Dawley rats were assigned randomly into 3 groups:a negative control group(NC group),an ovalbumin(OVA)-induced AR model group(AR group),and AR model group(ARE group)inhaled to PM 2.5 at 200μg/m~3,3 h/d,for 30 days.Nasal symptoms,levels of MUC5 AC in nasal lavage fluid(N...