Stimulation of collagenase production in human synovial fibroblast cultures by poly (I). poly (C).

Poly (I). poly (C) was found to induce collagenase secretion in both "normal" and "rheumatoid" synovial fibroblast cultures. Induction was time dependent, was maximal at 20-50 micrograms/ml poly (I). poly (C) and was dependent on de novo synthesis. Induction was prevented by hydrocortisone (0.1 microgram/ml) but inhibition of prostaglandin E production by diclofenac (0.2 microgram/ml) or ibuprofen (0.1 microgram/ml) did not affect collagenase production. Collagenase induction was accompanied by stimulation of hyaluronic acid and prostaglandin E production. This in vitro system may represent a model for the study of pathological secretory activities in the inflamed joint.