Protective Effect of Nedocromil Against Insulin Induced Airway Hyper-Reactivity
Keywords: Inhaled insulin, , Oscillograph, nedocromil, Tracheal muscle, Airway hyper-reactivity.
AbstractBackground: Use of inhalable insulin is limited because it causes airway hyper-reactivity. So present study was designed to ameliorate inhalational insulin induced airway hyper-responsiveness.Objectives: The objective of the study was to evaluate the acute effects of insulin on airway reactivity and protective effects of nedocromil against insulin induced airway hyper-reactivity on isolated tracheal tissues of guinea pigs in vitro.Material and Methods: This experimental study was carried out in Pharmacology department of Army Medical College Rawalpindi from January 2012 to July 2012. We observed acute effect of insulin (10-7- 10-3 M) and insulin pretreated with nedocromil (10-5 M) on isolated tracheal strip of guinea pig (n=6) in vitro by constructing cumulative concentration response curves. The tracheal smooth muscle contractions were recorded with Transducer on Four Channel Oscillograph.Results: Insulin significantly increased the tracheal smooth muscle contraction. The mean ± SEM of maximum amplitudes of contraction with insulin and insulin pretreated with nedocromil were 35 ± 1.13 mm and 27.8 ± 1.27 mm respectively. So nedocromil significantly antagonized insulin elicited contractile effect. Conclusion: Nedocromil significantly inhibited the insulin mediated airway hyper-reactivity in guinea pigs. So we suggest that pretreatment of inhaled insulin with nedocromil may have clinical implication in amelioration of its potential respiratory adverse effects.