Relationship between phosphodiesterase type 4 inhibition and anti-inflammatory activity of CI-1044 in rat airways.

The anti-inflammatory effects of CI-1044 and of the other selective PDE4 inhibitors rolipram and cilomilast were investigated in Brown-Norway (BN) rats, against lipopolysaccharide-induced tumor necrosis factor alpha (TNFalpha) production in whole blood and antigen-induced lung eosinophilia. In vitro, CI-1044 inhibited TNFalpha production with an IC(50) of 0.31 microm being equipotent to Cilomilast (IC(50) = 0.