Wound fluids mediate granulation tissue growth phases

The effects of exudates (wound fluids) from experimental granulation tissue on the synthesis of connective tissue components in fibroblast cultures were tested. The exudate from the early phase of granulation tissue (4 days after implantation) stimulated fibroblast proliferation and also the production of hyaluronic acid comparable to rat serum. On the contrary, the two later exudates (10 and 14 days after implantation) strongly inhibited fibroblast proliferation. These exudates also turned fibroblast glycosaminoglycan synthesis to more sulphate containing molecules. Collagen and protein synthesis were only slightly affected, the maximal collagen synthesis being obtained with the early phase wound fluid. The analysis of exudates and rat serum in sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the clear similarity the exudates from the later growth stages produced some new proteins, which may regulate the altered metabolism of cultured fibroblasts.