The Inhibitant Effects Of Parecoxib, A Cyclooxygenase-2 Inhibitor, in Acute Fentanyl Induced Hyperalgesia in Rats / 实用医学杂志

ABSTRACT

Objective To investigate the inhibitant effects of parecoxib, a cyclooxygenase-2 (COX-2) inhibitor, in acute fentanyl induced hyperalgesia in rats. Methods (1) Thirty SD rats (n=6 for each group) were subcutaneously injected with fentanyl (40 μg/kg × 4 times with a 15 min-interval) or saline to establish acute fentanyl induced hyperalgesia model, andparecoxib (5, 10 mg/kg) was administrated intraperitoneally in parecoxib group. Mechanical nociceptive thresholds were measured by the tail pressure test every hour during 1~4 hours and once a day during 1~5 days. (2) 24 SD rats (n = 6 foreach group) were subcutaneously injected with fentanyl as above described and randomly administrated intraperitoneally with parecoxib in 10 mg/kg in 15 min before and at the 4th hour and the 1st day after fentanyl injection except rats in the control group, mechanical nociceptive thresholds were measured by the tail pressure test at time points as above described. Results (1)Acute high dose fentanyl injection induced mechanical hyperalgesia and parecoxib (at 5 or 10 mg/kg)inhibited fentanyl induced hyperalgesia in rats. (2)Parecoxib inhibited fentanyl induced hyperalgesia at 15 min before and at the 4th hour after, but not on the 1st day after fentanyl injection. Conclusions This study provides the first evidence that subanalgesia doses of parecoxib had inhibitory effects on acute fentanyl induced hyperalgesia in time-dependent manners in rats.