[The significance of coagulation disorders and the inflammatory reaction in an infectious model of rheumatoid arthritis. II. Inhibition trials with antirheumatic drugs in the inflammatory reaction phase of erysipelas polyarthritis in rats].

The arthritic activity in the initial phase and during manifestation of experimental erysipelas in rats, an animal model for human rheumatoid arthritis, was studied by plethysmometrical methods. The development of body weight and specific pathologic alterations peculiar to the model such as keratitis, thrombosis of the aorta and gangrene of the tip of the tail served as additional parameters. In the volumetric analysis it could be shown that the first arthritic swelling on both hind legs develops symmetrically up to day 6 post infection in rats with about 200 g of body weight-and in contrast-on the 2nd p.i. in younger animals with about 120 g. The first maximal paw volume was measured on day 9 p. i., the greatest decrease in body weight-a reduction of 25%-on day 10 p. i. In addition the reaction of the animal model following the application of steroid and non-steroid symptomatically as well as cytostatically acting antirheumatic drugs was tested. Daily treatment with acetylsalicylic acid, indomethacine or hydrocortisone provoked more or less significant inhibition of arthritic swelling in the paw. Only at the onset of arthritis acetylsalicylic acid was more effective than the other antiphlogistic drugs. No measurable increase of paw volume during cyclophosphamide treatment could be evaluated. None of the antirheumatics used had a positive effect on body weight developement. In hydrocortisone and also in cyclophosphamide treated rats a greater decrease was obtained than in the infected controls. No thrombosis developed after cytostasis with cyclophosphamide. The advantages of this systemic connective tissue disease with regard to its comparability with human rheumatoid arthritis and due to the course of its arthritic manifestation are discussed, together with the disadvantages specific to the model and the experimental conditions.