Abstract

Responses in vitro to partially purified porcine leucocyte catabolin were studied in pig synovial fibroblasts.In serum-free cultures catabolin was found to stimulate secretion of prostaglandin E2 (PGE2) in a time and concentration-dependent manner. The initial stimulation of PGE2 secretion occurred only after a latent interval of six hours. In the same cell line catabolin was found to have no effect on the production of cyclic adenosine monophosphate (cAMP) at times ranging from 30 s to 20 min, even at concentrations up to 15 times greater than that required to promote accelerated release of glycosaminoglycans from cultured bovine nasal cartilage. It is therefore concluded that in pig synovial fibroblasts catabolin evokes a delayed secretion of PGE2 but does not alter cyclic AMP production.