The influence of cyclooxygenase-2 inhibitor on lunbar disc herniation:An experimental study

Objective To analyse the inflammatory reaction in the early stage of lumbar disc tissue under selective cyclooxygenase-2 (COX-2)inhibitor therapy,and to assess the influence of COX-2 inhiitor on regression of herniated discs. Methods Thirty two rabbits were used and divided randomly into drug group and non-drug group,sixteen rabbits in each group. A new disc herniation model was made by Yoshida's method at L5-6 discs,the drug group were given COX-2 ihhibitor(Celecoxib)5mg/kg/day together with feeds,all rabbits were sacrificed arter 4 week,then 8 of the L5-6 discs were harvested in each group,the size of the herniated discs was measured using a special way and PGE2 was detected by radioimmunoassay. For the left eight L5-6 discs in each group,5 um thin sections were stained with monoclonal antibodies CD-68 for macrophages. Results The content of PGE2 in drug group was 36.01±6.90pg/mg,61.07±8.75pg/mg (P0.05);The size of herniated disc in drug group was 2.20±0.18mm2,and 194±0.11mm2 in non-drug group (P 0.05). Macrophages were detected in all of the eight non-drug herniated lumbar disc tissue,in 4 of 8 discs(50%)were found abundant cels(++),2 discs (25%)were (++)in the drgu group,and nomacrophages were observed in one discs. Conclusion Celecoxib obviously relieves inflammation induced by disc herniation,but may also suppress the spontaneous regression of herniated discs which maybe due to less macrophages infiltrating. However,the influence of COX-2 inhibitors on lumbar disc herination during the early stage needs furher study.