1 Effect of sildenafil on acrolein-induced airway inflammation and mucus production in rats

Airway inflammation with mucus overproduction is a distinguishing pathophysiological feature of many chronic respiratory diseases. Phosphodiesterase (PDE) inhibitors have shown anti-inflammatory properties. In this study, we examined the effect of sildenafil, a potent inhibitor of PDE5 that selectively degrades cGMP, on acrolein-induced inflammation and mucus production in rat airways. Rats were exposed to acrolein for 14 and 28 days. Sildenafil or distilled saline was administered intragastrically prior to acrolein exposure. Bronchoalveolar lavage fluid (BALF) was acquired for cell count and detection of proinflammatory cytokine levels. Lung tissue was examined for cGMP content, nitric oxide (NO)-metabolite levels, histopathologic lesion scores, goblet cell metaplasia and mucin production. The results suggested that sildenafil pretreatment reversed the significant decline o