Figure 7.

Effects of M₁PK on airway responsiveness in mice sensitized and challenged with ovalbumin. (a and b) Effects of M₁PK on peak airway pressure (airway pressure time index). Immediately before ovalbumin aerosol challenge, mice were intraperitoneally injected with either 20 U M₁PK in 1% BSA/PBS (M₁PK-treated group) or with 1% BSA/PBS (control group). Within 1–6 h after ovalbumin aerosol challenge, M₁PK- and BSA-treated mice were tested for airway responsiveness to increasing concentrations of MCh. Mice tested 3–6 h after the end of ovalbumin aerosol challenge were given a ‘top-up' injection of M₁PK (20 U) or 1% BSA/PBS. (c) Average response to methacholine between 20 and 50 s after injection of methacholine. Data shown are mean±s.e.mean. A multivariate analysis of variance for repeated measures was carried out. ^*P<0.05 BSA versus M₁PK and alum treatment. BSA, bovine serum albumin; M₁PK, M₁-type pyruvate kinase; MCh, methacholine; PBS, phosphate-buffered saline.