Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Combined forced oscillation and forced expiration measurements in mice for the assessment of airway hyperresponsiveness. | Shalaby et al. Respiratory Research 2010 11 82 http content 11 1 82 RESPIRATORY RESEARCH RESEARCH Open Access Combined forced oscillation and forced expiration measurements in mice for the assessment of airway hyperresponsiveness Karim H Shalaby1 Leslie G Gold2 Thomas F Schuessler2 James G Martin1 and Annette Robichaud 2 Abstract Background Pulmonary function has been reported in mice using negative pressure-driven forced expiratory manoeuvres NPFE and the forced oscillation technique FOT . However both techniques have always been studied using separate cohorts of animals or systems. The objective of this study was to obtain NPFE and FOT measurements at baseline and following bronchoconstriction from a single cohort of mice using a combined system in order to assess both techniques through a refined approach. Methods Groups of allergen- or sham-challenged ovalbumin-sensitized mice that were either vehicle saline or drug dexamethasone 1 mg kg ip -treated were studied. Surgically prepared animals were connected to an extended flexiVent system SCIREQ Inc. Montreal Canada permitting NPFE and FOT measurements. Lung function was assessed concomitantly by both techniques at baseline and following doubling concentrations of aerosolized methacholine MCh - 250 mg ml . The effect of the NPFE manoeuvre on respiratory mechanics was also studied. Results The expected exaggerated MCh airway response of allergic mice and its inhibition by dexamethasone were detected by both techniques. We observed significant changes in FOT parameters at either the highest Ers H or the two highest Rrs RN G MCh concentrations. The flow-volume F-V curves obtained following NPFE manoeuvres demonstrated similar MCh concentration-dependent changes. A dexamethasone-sensitive decrease in the area under the flow-volume curve at the highest MCh concentration was observed in the allergic mice. Two of the four NPFE parameters calculated from the F-V curves and FEF50 also
