Platelet-derived growth factor-BB accelerates wound closure in a new mesentery culture model without macrophages.

Platelet-derived growth factor-BB has multiple effects in vitro and has been demonstrated to accelerate wound healing in several animal models, but its precise mechanisms of action in vivo have not been fully explained. A rat mesentery culture model was developed, and platelet-derived growth factor-BB (100 ng/ml) was added to the medium containing 2% fetal calf serum for examining its closure effects. The mesentery specimens were stained by routine hematoxylin and eosin and immunohistochemical staining for macrophages. A significant improvement in closure rate and complete closure rate was seen when platelet-derived growth factor-BB was added to the medium compared with the controls (p < 0.05). There are significantly fewer macrophages in the in vitro specimen than in the in vivo specimen. In conclusion, platelet-derived growth factor-BB can contribute to wound closure of a mesenteric defect even without macrophages, suggesting a second mechanism in which it can act directly on mesenchymal cells during wound healing. This tissue-culture model is useful for gaining further insights into growth factor interactions and wound healing.