Adjuvant arthritis: influence of the adjuvant volume and composition on the established arthritis

Adjuvant arthritis remains an interesting model for the evaluation of therapeutic agents and for the study of inflammatory mechanisms. The severity and time course of the primary nonspecific inflammation and of the induced polyarthritis are influenced by the composition and volume of the injected adjuvant. The injection of complete adjuvant produces always an oedema which is much greater than the sum of the oedemas induced by mineral oil or mycobacteria alone. In Lewis rats, highly susceptible to adjuvant arthritis, the intensity of the induced lesions increases with the injected oil volume and for equal volumes is maximal with 500 micrograms of Mycobacterium butyricum. In the injected paw the specific immune character of the inflammation is more important when a small volume of adjuvant is used and is maximal for 500 micrograms of mycobacteria in 0.1 ml of mineral oil.