ABSTRACT
OBJECTIVE: The aim of this study is to investigate the effects of topical growth hormone (GH) treatment on skin wound healing in mice. MATERIALS AND METHODS: An excisional wound healing model was established on male Swiss mice, and wound healing ability was evaluated by macroscopic and histologic analyses of mice treated with topical 10-8 M and 10-7 M of GH versus the mice receiving ve- hicle alone. Wound tissues were collected on post treatment days 3, 7, and 14. Skin fragments were subjected to hematoxylin and eo- sin and Masson's trichrome staining for morphological analyses. The expression of type I collagen and platelet endothelial cell adhesion molecule 1 (CD31) was detected by immunohistochemical analysis. RESULTS: Topical treatment with GH resulted in faster wound closure rates at all time points analyzed versus those observed in the control group (day 3: 18.3 ± 3.1 vs. 44.4 ± 7.4, 43.6 ± 0.6; day 7: 41.7 ± 6.3 vs. 73.8 ± 6.6, 71.3 ± 5.8; day 12: 94.3 ± 3.9 vs. 100 ± 0, 100 ± 0). Histological analysis of the wound on post treatment day 3 revealed a more diffused in ltration of in ammatory cells in the group treated with GH. After day 7, GH-treated animals began form- ing granulation tissue, and there was an increase in in ammatory cell in ltration. The GH signi cantly increased the expression of type I collagen (day 7: 57.4 ± 4.0 vs. 120.2 ± 9.7, 79.3 ± 7.9; day 14: 218.2 ± 10.4 vs. 301.5 ± 9.1, 235.0 ± 7.5) as well as the number of blood vessels (day 7: 10.0 ± 2.4 vs. 15.3 ± 2.0, 10.1 ± 2.2; day 14: 3.2 ± 0.8 vs. 5.6 ± 2.0, 6.2 ± 2.2) in the injured area. CONCLUSIONS: The GH accelerates the closure of skin wounds by resolving the in- ammatory phase faster, accelerating reepithelialization and collagen deposition, and stimulating angiogenesis.
