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 ha s been demonstrated to accelerate wound healing in several animal mode ls, but its precise mechanisms of action in vivo have not been fully e xplained. A rat mesentery culture model was developed, and platelet-de rived growth factor-BB (100 ng/ml) was added to the medium containing 2% fetal calf serum for examining its closure effects. The mesentery s pecimens were stained by routine hematoxylin and eosin and immunohisto chemical staining for macrophages. A significant improvement in closur e rate and complete closure rate was seen when platelet-derived growth factor-BB was added to the medium compared with the controls (p < 0.0 5). 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-cultu re model is useful for gaining further insights into growth factor int eractions and wound healing.