Expression of vascular endothelial growth factor receptor-2 in the muscle flap with ischemic injury in rats

Background. Ischemia of muscle flaps is a significant problem in reconstructive surgery. Administration of either recombinant vascular endothelium. growth factor (VEGF) protein or gene transfers has been conducted to improve the survival of ischemic tissue. These biophysiological functions of VEGF are mediated through its receptor. In this study the changes of expression in VEGF receptor mRNA in muscle flaps with acute ischemia were examined in a rat gracilis muscle flap model. Materials and methods. Twenty-four Sprague Dawley rats were used. The ischemia of the flap was induced by clamping its vascular pedicle. At 3-, 6-, and 18-h intervals, the flaps were biopsied for histology and examination of VEGFR-2 mRNA gene expression. The muscle flap without ischemia was used as the control. Results. The results showed that the VEGFR-2 mRNA level was significantly increased 3 h after ischemia was induced and then attenuated to the baseline at 6 and 18 h ischemia. Conclusions. This study delineated the changes in expression of VEGFR-2 receptor in muscle flap in several postischemic intervals and provided a timeframe for the clinical application of VEGF. (C) 2007 Elsevier Inc. All rights reserved.