Anti-allodynic effects of oral COX-2 selective inhibitor on postoperative pain in the rat.
OBJECTIVE
To examine the effect of a cyclooxygenase (COX)-2 inhibitor on the maintenance of mechanical allodynia induced by skin incision (an animal model of postoperative incident pain) in the rat. Also, to compare the effect of a COX-2 inhibitor with that of a nonselective COX-1 and COX-2 inhibitor and B2 receptor antagonist.


METHODS
A 1 cm longitudinal skin incision was made in the plantar aspect of the foot. JTE522 (1-100 mg x kg(-1)), a COX-2 inhibitor, indomethacin (1-30 mg x kg(-1)), a nonselective COX-1 and COX-2 inhibitor, or FR173657 (10 and 100 mg x kg(-1)), a bradykinin B2 receptor antagonist, was administered orally five minutes after the end of the surgery. The level of mechanical allodynia was assessed by measuring the frequency of foot withdrawal in response to the application of a 12.5 g on Frey filament at 2, 4, 6, 8 and 24 hr after the drug administration.


RESULTS
Oral administration of JTE522 or indomethacin attenuated the maximum response frequency in a dose-dependent manner at a dose between 1 and 30 mg x kg(-1) (P < 0.05). Oral FR 173657, (100 mg x kg(-1)), had no effect on the maximum response frequency.


CONCLUSIONS
These data indicated that a COX-2 inhibitor attenuated the level of mechanical allodynia in the rat model of postoperative pain.
Yamamoto
T
T
Department of Anesthesiology, School of Medicine, Chiba University, Japan. yamatat@med.m.chiba-u.ac.jp
Sakashita
Y
Y
Nozaki-Taguchi
N
N
D000818:Animals; D001557:Benzenesulfonates / Q000627:therapeutic use*; D065168:Bradykinin Receptor Antagonists; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007213:Indomethacin / Q000627:therapeutic use; D007527:Isoenzymes; D008297:Male; D010080:Oxazoles / Q000627:therapeutic use*; D010147:Pain Measurement / Q000187:drug effects; D010149:Postoperative Pain / Q000188:drug therapy*; D011451:Prostaglandin-Endoperoxide Synthases; D051381:Rats; D017207:Rats, Sprague-Dawley; D000096926:Benzenesulfonamides
D001557:Benzenesulfonates; D065168:Bradykinin Receptor Antagonists; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007213:Indomethacin; D007527:Isoenzymes; D010080:Oxazoles; D011451:Prostaglandin-Endoperoxide Synthases; C110453:4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide; D000096926:Benzenesulfonamides