title: Nasal methacholine challenge and ipratropium therapy. Laboratory studies and a clinical trial in perennial rhinitis.
mesh_terms: D001286:Atropine Derivatives / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D009241:Ipratropium / Q000627:therapeutic use*; D008297:Male; D008688:Methacholine Compounds; D009299:Nasal Provocation Tests; D010276:Parasympatholytics / Q000627:therapeutic use*; D010919:Placebos; D012221:Rhinitis, Allergic, Perennial / Q000188:drug therapy*
chemical_list: D001286:Atropine Derivatives; D008688:Methacholine Compounds; D010276:Parasympatholytics; D010919:Placebos; D009241:Ipratropium