[Clinical significance of serum dipeptidyl aminopeptidase IV in rats with adjuvant arthritis].

Serum dipeptidyl aminopeptidase IV (DAP IV) activity in rats with adjuvant arthritis (AA) were studied. DAP IV activity was significantly low in AA rats (37.7 +/- 14.1 mU/ml, n = 15) compared with control (63.7 +/- 9.0 mU/ml, n = 8) and indomethacin-treated (IDM) AA rats (55.6 +/- 14.2 mU/ml, n = 15). In addition, serum DAP IV activity was inversely correlated with hindpaw arthritis score both in AA rats and IDM-AA rats. Among serum inflammatory index examined, acid soluble glycoprotein, sialic acid were inversely correlated and albumin was positively correlated with DAP IV activity in AA and IDM-AA rats. The role of serum DAP IV remains unknown, but, it seems possible that DAP IV might modify the clinical course of AA rats in connection with its effects on the immune regulatory system.