Potential of Inducible Nitric Oxide Synthase as a Therapeutic Target for Allergen-Induced Airway Hyperresponsiveness: A Critical Connection to Nitric Oxide Levels and PARP Activity

Figure 2

Effect of iNOS inhibition by L-NIL on AHR manifestation upon acute or chronic exposure to OVA in mice. C57BL/6 mice were subjected to OVA sensitization followed by an acute (a) or chronic (b) challenge to aerosolized OVA or left unchallenged. A group of WT mice were administered i.p. 5 mg/kg of the specific iNOS inhibitor (L-NIL) or saline 30 min after each OVA challenge. Penh was recorded 24 h after the last challenge using a whole body plethysmograph system before and after the indicated concentrations of aerosolized methacholine (MeCh). Results are plotted as maximal fold increase of Penh relative to baseline (0 μM MeCh) and expressed as mean ± SEM, where mice per group. , difference from OVA-challenged mice; . , difference from control unchallenged mice; ; ns, no significant difference.

(a)

(b)