Figure 4

Effect of albuterol on AHR in allergic mice. Respiratory mechanics time course following methacholine challenge. Parameters from fitting the constant phase model to input impedance data; R _n is Newtonian resistance of the conducting airways; H is lung elastance and G is tissue resistance. Left column: Allergic Balb/C mice; AHR measured as dose-response time-course to increasing doses of methacholine inhalation in OVA sensitized Balb/C mice. Animals were treated with (RS)-, (R)- or (S)- albuterol (n = 11, 12 and 10) twice daily for seven days with the last administration 18 hours before experiment. PBS (n = 10) was used as vehicle control. H was significantly elevated over PBS control at the 12.5 and 50 mg/ml doses of methacholine by (RS)-, (R)- and (S)- albuterol. * p < 0.05, ** p < 0.01 and *** p < 0.001. Right column: Naïve Balb/C mice; AHR assessment in naïve Balb/C mice. Animals were treated with (RS)-, (R)-, (S)- albuterol or control PBS, n = 8 per group.