Time course of the change in hind paw volume after the induction of arthritis. Rats in all arthritic groups showed an increase in their paw volume until day 8; however, this increase in the azothioprine (AZ)-treated, chloroquine (CQ)-treated and sodium aurothiomalate (gold salt (GS))-treated arthritic rats was not significantly different from the normal control rats, and also no further increase in the paw volume was noticed in these groups. In contrast, arthritic rats treated with methotrexate (MTX) and indomethacine showed a gradual increase in their paw volume over a period of 22 days, but this increase was nonsignificant compared with normal control rats. The arthritic rats treated with D-penicillamine (D-PEN) or saline showed a significant increase in their paw volume over the period of 22 days (P < 0.006). Inbox pictures, difference between the arthritic rat paw and the normal rat paw. Results expressed as mean ± standard error (n = 6). AC, arthritic control; AIA, adjuvant-induced arthritis; DC, drug control; NT, no treatment; Sal + Art, saline and arthritis.