Effects of ketamine on iNOS protein expression in pulmonary tissues from ovalbumin-sensitized and -challenged rats. Protein expression of iNOS in lung homogenates obtained from experimental rats was examined by Western blotting, with a representative example from each group shown. β-actin was detected as an internal control. The groups are as shown in Figure 1. (A) Lane 1, PBS; lane 2, OVA; lane 3, 12.5 mg/ml; lane 4, 25 mg/ml; lane 5, 50 mg/ml; lane 6, 50 μg/kg i.p,; lane 7, 100 μg/kg. (B) Densitometric analysis of iNOS protein levels in lungs obtained from rats in each group. The bars represent the mean ± SEM, with laser densitometry used to standardize iNOS protein levels with respect to that of β-actin (ratio of iNOS/β-actin, n = 6–8/group). # P < 0.05 vs. PBS control; * P < 0.05 vs. OVA control.