Basic fibroblast growth factor in the early human burn wound.

The role of endogenous growth factors in normal wound healing is not clear. Most of the data on growth factors in healing wounds have been obtained from the application of recombinant exogenous growth factors to animal and human wounds. We describe the immunolocalization of basic fibroblast growth factor (bFGF) in the injured dermis of skin from patients with partial and full-thickness burns. Three antibodies demonstrate an extracellular staining pattern of bFGF corresponding to areas of tissue injury that was most intense in specimens collected between 4 and 11 days post-burn injury. In contrast, bFGF staining appeared markedly decreased by Postburn Day 17 and was more consistent with uninjured tissue in a 30-day-old burn that had virtually reepithelialized. Basic FGF staining in the non-burned skin from the same patients was restricted to the dermal capillary basement membranes and the sweat glands, which is consistent with other reports of immunoreactive bFGF localization in normal adult skin. The immunohistochemical results were confirmed with Western immunoblots of the same tissue. The major band at 16.5 kDa, which is within the recognized range of the bFGF molecule's several forms, was detected in both burned and unburned tissue from the same patient. These findings support the hypothesis that bFGF is a presynthesized mediator that is stored in either the cells or extracellular matrix, is released locally from sites of direct injury, and may be important in early wound healing.