Canine platelet factors stimulate glycosaminoglycan synthesis by synovial cell and organ cultures.

Glycosaminoglycan (GAG) synthesis in both canine synovial cell and organ cultures was stimulated by the addition of canine platelet extracts. Canine platelet factor (CPF) biologic activity obtained from acidic ethanol platelet extracts was partially purified, and resembled CTAP-III, a characterized human platelet protein known to stimulate human synovial cell GAG synthesis. These results identify a canine platelet CTAP factor activity, and indicate that the synoviocytes of organ-cultured synovial villi can respond to platelet factors which are potential mediators of synovial GAG synthesis.