Questionable effects of Myocrisin in experimental arthritis in rabbits.

In 18 rabbits arthritis was induced in one knee joint by injection with 0.2 ml 3% ovalbumin 4 weeks after sensitization by 3% ovalbumin and 2 mg/ml tubercle bacilli suspended in Freunds incomplete adjuvant. Half of the rabbits were treated with Myocrisin 4 mg i.m. once a week during the experimental period lasting 4-5 months. At killing, both knee joints were examined macroscopically and microscopically. In all rabbits a distinct synovitis was found in the injected knee joint. Histologically, the changes were most pronounced in the rabbits not treated with Myocrisin. An activity index of the synovial membrane changes in the Myocrisin-treated and untreated cases was calculated to 6.3 and 3.6 respectively. Some changes were also found in the uninjected knee joints of 50% of the rabbits. In contrast to some other works, this preliminary investigation suggests that antigen-induced experimental arthritis is suppressed by gold. We feel that this model of experimental arthritis may be suitable for trying out the effect of various drugs.