COX inhibitors downregulate PDE4D expression in a clinical model of inflammatory pain

Tumor necrosis factor-alpha (TNF-alpha) has a central role in inflammation and is modulated by prostaglandin E-2 (PGE(2)) and cyclic adenosine monophosphate (cAMP). Using microarray, quantitative real-time polymerase chain reaction (qRT-PCR), and protein detection techniques, we showed that ketorolac and rofecoxib had no significant effect on TNF-alpha gene expression in oral mucosal biopsies 3 h after surgery. They both, however, downregulated the gene and protein expression of phosphodiesterase type 4 (PDE4D), which might represent a novel mechanism contributing to their analgesic and anti-inflammatory effects.