Experimental Study On The Effect And Mechanism Of BFGF Treating The Rat Skin Injure Induced By β Radiation

Objective: To study the effect of bFGF healing the skin radiaton burn and the mechanism of bFGF promoting the ulcer healing on the base of establishing the animal II ~0 β radiaton burn model in skin.Methods: 54 female SD rats are divided into 3 groups randomly: (1) 15Gy group 14 rats; (2)45Gy dose bFGF treating group 20 rats; (3)45Gy dose control group 20 rats. The healing time and the healing rate were observed,parts of the wound surface tissues were taken on the 0th,1th,3th,5th week respectively after the ulcer had been formed in the rats' irradiated site. Microtome sections were made after the tissue samples embedded by paraffin block and done by HE stain. The expression of bFGF and VEGF were studied by SP immunohistochemical method, mRNA and protein of MMP-2,9 in the skin samples were measured by RT-PCR and Western blot methods.Results: 1.The II~0 β radiation burn model on SD rats skin was established successfully under 45Gy dose. 2.Compared with the 45Gy dose control group,the uclers' healing time was shortened and the healing rate was improved obviously on the rats skin of bFGF treating group,the result was significantly different(P<0.01). 3.The expression of bFGF and VEGF werehigher in the ulcers of bFGF treating group than that of 45Gy dose control group at the same period. The multiplication of fibroblast, epithelial cell and vascular endothelial cell was more active in the wound surface of treating group than that of control group. 4.the synthesis of mRNA and protein of MMP-2,9 was significantly higher in the treating group than that of control group significantly.Conclusion: 1.45Gy dose (3 radiation was proved to be a trustworthy method producing II ° ucler on SD rat skin. 2.bFGF can promote the radioactivity ucler healing efficiently. The mechanism may be that the expression of bFGF and VEGF decreased by ionizing radiation were enhanced by giving exogenous growth factor and attain a peak value which is necessary to a wound surface healing. 3.The high expression of mRNA and protein of MMP-2,9 in the ulcer after giving bFGF demonstrates that the synthesis of mRNA was enthanced. bFGF probably has something to do in refraining the high expression of the apoptosis induction gene and excessive apoptosis due to ionizing radiation.