Topical Growth Hormone Accelerates Wound Healing in Mice.

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.