Effect of Thymosin β4 on the Survival of Random Skin Flaps in Rats.

BACKGROUND: Random skin flaps can be used throughout the hands and fingers. Thymosin β4 can increase blood flow and reduce ischemia-reperfusion injury; the study was undertaken to investigate the effect of thymosin β4 on the survival of random skin flaps. METHODS: A total of 45 male Sprague-Dawley rats were used and subjected to a random-pattern skin flaps operation. Rats were randomly divided into three groups: a control group (group A: intraperitoneal injection of saline, 5 mg/kg/d) and two treatment groups (group B: intraperitoneal injection of thymosin β4, a single 5 mg/kg dose per day) and (group C: intraperitoneal injection of thymosin β4, 5 mg/kg dose twice per day). The flap surviving area was measured after 7 days, and tissue samples were stained with hematoxylin and eosin. Vascular endothelial growth factor (VEGF) expression was determined using immunohistochemical methods. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined with kits. RESULTS: Thymosin β4 significantly reduced the necrotic area in the treatment groups after 7 days compared with the control group, and the rats receiving thymosin β4 5 mg/kg twice per day had the highest survival rate. VEGF expression and SOD activity markedly increased in the treatment groups compared with the control group, whereas MDA levels were lower in the treatment groups than in the control group. CONCLUSION: Thymosin β4 may have a dose-dependent effect to promote the survival of random skin flaps.