Objective: To evaluate the effects of COX-1 and/or COX-2 inhibition in a model of chronic esophagitis in rabbits.
Methods: Both high- and low-grade esophagitis were induced in rabbits by the perfusion of acidified pepsin. Rabbits were treated with either a selective COX-2 inhibitor (DFU[3-(3-Fluorophenyl)-4-(4-Methanesulfonyl)-5,5-Dimethyl-5H-Furan-2-One];30 mg/Kg/day), a nonspecific COX inhibitor (indomethacin; 2 mg/Kg/day), or a COX-1 preferential inhibitor (piroxicam; 2 mg/Kg/12 h).
Results: Prostaglandins are derived from COX-1 activity in the normal esophagus. Both low- and high-grade esophagitis are associated with a progressive increase of COX activity, which is partially dependent on the COX-2 isoform. DFU reduced muscosal damage in both models of esophagitis. However, indomethacin did not affect significantly mucosal damage, and piroxicam increased damage in low-grade esophagitis.
Conclusions: COX-1 activity is constitutive in the rabbit esophageal mucosa, but both COX-2 and COX-1 activity are increased under the impact of acidified pepsin. Treatment with the COX-2 inhibitor DFU is associated with improvement of mucosal damage, which may have therapeutic implications.