The Impact Of Genetic Polymorphisms Of β₂-adrenegic Receptor On Bronchodilator Response In COPDs

Objective: To investigate the impact of genetic polymorphisms of β-2-adrenegic receptor(β2-AR) in 16 and 27 position on bronchodilator response in COPDs.Methods: We genotyped 34 participants by sequencing ,and divided into A: (Arg16Arg),B: (Arg16Gly+Gly16Gly); C: (Gln27Gln),D: (Gln27Glu+Glu27Glu)by genotyping. Each group received 500ug of inhaled albuterol, 80pg ofinhaled impragtopium bromide or 500ug+80ug of inhaled ipratropiumplus albuterol. Lung funtion (FEV1 %) was assessed before drug administration and 15, 30,60,120,180,360 min therafter. We further analyzed effects of genetic polymorphisms on bronchodilator response.Results: The genotypes of 34 COPDs were (A) 16 Argl6Arg, (B)18 Arg16Gly + Gly16Gly in 16 position respectively; the baseline FEV1%, sex, age or smokeing index of two groups had no difference, but the the genotypes(A) Arg16Arg, (B)Arg16Gly+Gly16Gly in 16 position had more different effect on albuterol-evoked FEV1% average percentage increase and Maximal percentage increase in FEV1% (FEV1%) (p<0. 05, p<0.05). In B group, afteradministration of inhaled 80ug impragtopium bromide, average percentageincrease in FEV1% significantly improved compared with average percentage increase in FEV1 % with albuterol(p<0.05). Combination treatment with albuterol plus impratropium bromide provided significantly(p<0.05,p<0.05) greater improvements in average percentage increase in FEV , % than bronchodolators given alone.Conclusions: The β2-adrenergic receptor gene polymorphism in 16 position is a major determinant of bronchodilator response to albuterol and impragtopium bromide in COPDs.