OBJECTIVETo explore the differences of PDGF and EGF expression in the wound healing between fatal and adult.

METHODSWith the established animal model of fetal scarless healing and the adult samples, an immunohistochemical technique was used to evaluate the expression of PDGF and EGF in the normal adult skin, normal fetal skin, and the process of their wound healing.

RESULTS1. The expression of the PDGF was not found in the fetal skin, but a mild amount of the PDGF was shown in the epidermis and the upper dermal layer 12 hours and 1 day after the wounding process. In the normal adult skin, expression of PDGF was shown in the dermal fibroblasts, macrophagocytes and blood capillaries, and a strong expression was presented during its wound healing process. 2. In the fetal skin, the expression of the EGF was seen in the epidermis, hair follicles, sebaceous glands and sweat glands, but there were no markedly changes during the wound healing. In the adult skin, a positive stain of the EGF was shown in the basal layer of the epidermis while the mild stain in hair follicles and sweat glands. The level of the expression became gradually decreasing with the time going in the wounded adult skin.

CONCLUSIONThe different expression of growth factors between fetal and adult skin in wound healing may be one of the important reasons that the fetal wound could produce scarless healing.