Effect of cyclosporine-A on connective tissue deposition in experimental inflammatory lesions

The effect of cyclosporine-A, a potent immunosuppressant, on the development of experimental inflammatory lesions in rats was studied both histologically and biochemically. Continuous treatment with cyclosporine was begun after the implantation of sponges impregnated with heat-killed Mycobacterium tuberculosis and continued for up to 63 days. Cyclosporine-A significantly reduced the numbers of neutrophil polymorphonuclear leukocytes and lymphocytes present during both the acute and chronic phases. In addition, greater amounts of mature fibrous tissue were present in the sponges removed from animals which had been treated with cyclosporine-A. Biochemical analyses of the collagen and glycosaminoglycan content of the sponges at varying times confirmed that cyclosporine-A can influence the deposition of connective tissue macromolecules. These data provide additional evidence that cyclosporine-A affects not only the inflammatory response but also influences subsequent connective tissue metabolism.