650 Exploring the Mechanism of Wound Healing in Rats of Different Ages Using a Burn Model

Abstract

Abstract Introduction This study attempted to explore the mechanism of wound healing in rats of different ages using an reliable and reproducible burn model. Methods A self-made metal column, heated in a boiling water bath, was applied for different time periods to the lower back of rats of different ages in burn creation. Wounds were observed visibly at different time points post burning. Biopsies were obtained and examined at 72 h post burn to determine the depth of burns. In exploring the mechanism of wound healing in rats of different ages, we used primary antibodies including Anti-EGFR [EP38Y] (ab52894) and p75NTR (D4B3) for immunofluorescence of the skin paraffin sections (5μm) obtained from normal rats and on day 3 post burn creation. And we measured the expression of CD271 and EGFR. Results The contact durations producing the desired depth of injury in the rat model under constant temperature and pressure were: 3 seconds (deep second degree) and 5 seconds (third degree) in 1-month-old rats; 3 seconds (superficial second degree), 5 seconds (deep second degree), and 7–9 seconds (third degree) in 2-month-old rats; 3–5 seconds (superficial second degree), 7–9 seconds (deep second degree), and 11–13 seconds (third degree) in 12- and 18-month-old rats. The distribution of CD271 and epidermal stem cells showed no age-related changes (P＞0.05), and the expression of EGFR decreased with age in normal rats (P＜0.001). Compared with normal rats, the content of CD271 and epidermal stem cells and the expression of EGFR increased in burned rats. Conclusions The reliable and reproducible experimental model produces consistent burn injuries in rats of different ages. The number of CD271 and epidermal cells and the expression of EGFR increase during wound healing in rats, suggesting that CD271, epidermal cells and EGFR in epidermal stem cell membranes are associated with burn wound healing. Applicability of Research to Practice This research may be used in clinical practice in the future for better wound care.