Effect of intra-articular carboxymethylated chitosan injection on nitric oxide synthase expression in cartilage of osteoarthritis in a rabbit model / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effect of intra-articular carboxymethylated ehitosan(CM- CTS)injection on inducible nitric oxide synthase(iNOS)expression in cartilage at the early stage of os- teoarthfitis(OA).Methods Thirty-two white rabbits were underwent unilateral anterior cruciate ligament transection(ACLT)and were randomly divided into 4 groups 5 weeks after transection.Rabbits of group A re- ceived 0.3 ml of 2% high molecular weight CMCTS(H-CMCTS)once every two weeks.Rabbits in group B were treated using 2% low molecular weight(L-CMCTS)CMCTS atthe same intervals.Group C rabbits were injected intra-articularly with 0.3 ml of 1% sodium hyaluronate(Na-HA)once a week.Animals of group D were not injected.At sacrifice,11 weeks following surgery,the expression of iNOS in cartilages was analyzed by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR)methods.Results Both immunohistochemistry and RT-PCR showed that the level of iNOS expression of cartilage in CMCTS in- jection groups was lower than that in Na-HA injection group and the untreated group.There was no significant difference in iNOS expression between the two different molecular weight CMCTS injection groups. No signifi- cant difference of iNOS expression in cartilage was found between Na-HA injection group and the untreated group.Conclusion CMCTS suppresses iNOS expression in cartilage during the early stage of OA.Na-HA treatment has no effect on iNOS expression in cartilage.