title: A comparative study of the beneficial effects of ipratropium and beclomethasone against insulin-induced tracheal tissue contraction in a guinea pig model.
abstract: OBJECTIVE
  To evaluate the acute effects of insulin on airway reactivity and the protective effects of beclomethasone and ipratropium against insulin-induced airway hyperresponsiveness on isolated tracheal smooth muscle in a guinea pig model.
  
  
  METHODS
  The trachea of each guinea pig was excised; one end of the tracheal strip was attached to the hook of the oxygen tube of a tissue bath and the other end was connected to a research-grade isometric force displacement transducer. The effects of varying concentrations of insulin (10(-7) to 10(-3)M) and insulin pretreated with a fixed concentration of beclomethasone (10(-6)M) and ipratropium (10(-6)M) on the isolated tracheal tissue were studied by constructing cumulative concentration-response curves. Changes in tracheal smooth muscle contractions were recorded on a 4-channel oscillograph.
  
  
  RESULTS
  The means ± standard error of the mean of the maximum amplitude of contraction with increasing concentrations of insulin and of insulin pretreated with fixed concentrations of beclomethasone and ipratropium were 35 ± 1.13, 22 ± 1.15 and 27.8 ± 1.27 mm, respectively.
  
  
  CONCLUSIONS
  The data showed that beclomethasone inhibited the contractile response of insulin to a greater extent than ipratropium. Thus we suggest that inhalational insulin pretreated with beclomethasone may be more efficacious than with ipratropium for the amelioration of potential respiratory adverse effects such as bronchoconstriction.
authors.affiliation: Department of Pharmacology and Therapeutics, Army Medical College Rawalpindi, National University of Sciences and Technology, Islamabad, Pakistan.
authors.forename: Mahjabeen
authors.initials: M
authors.lastname: Sharif
authors.forename: Bushra Tayyaba
authors.initials: BT
authors.lastname: Khan
authors.forename: Shoaib
authors.initials: S
authors.lastname: Bin Aleem
authors.forename: Mohammad Asim
authors.initials: MA
authors.lastname: Anwar
mesh_terms: D000818:Animals; D018927:Anti-Asthmatic Agents / Q000494:pharmacology*; D001507:Beclomethasone / Q000494:pharmacology*; D001993:Bronchodilator Agents / Q000494:pharmacology*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects*; D009241:Ipratropium / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth; D011897:Random Allocation; D014132:Trachea / Q000187:drug effects*; D014133:Tracheal Diseases / Q000188:drug therapy
chemical_list: D018927:Anti-Asthmatic Agents; D001993:Bronchodilator Agents; D007328:Insulin; D009241:Ipratropium; D001507:Beclomethasone