Background: The goal of this study was to evaluate in vitro and in vivo the effects of up-regulation of the proangiogenic hypoxia inducible factor (HIF)-1α induced by dimethyloxalylglycine on endothelial cell cultures and on skin flap survival.
Methods: Human umbilical vein endothelial cell cultures were exposed to hypoxic conditions, to dimethyloxalylglycine, and to cobalt chloride for up to 24 hours. Expression of HIF-1α and vascular endothelial growth factor (VEGF) in cell culture media was analyzed. In vivo, 20 male Wistar rats were assigned randomly to either the treatment group (dimethyloxalylglycine intraperitoneal injection, n = 10) or the control group (saline intraperitoneal injection, n = 10). A dorsal skin flap was raised in all animals and sutured back into place. Flap survival was evaluated on postoperative day 7 by laser Doppler and digital planimetry.
Results: In vitro treatment of human umbilical vein endothelial cells during a 24-hour period showed a significant elevation of VEGF expression with dimethyloxalylglycine exposure (92 ± 35 pg/mg total cellular protein) or hypoxia exposure (88 ± 21 pg/mg total cellular protein) compared with controls (23 ± 10 pg/mg total cellular protein) (p < 0.05 for both). In vivo experiments showed a significant decrease of flap necrosis in the treatment group animals versus controls (35.95 ± 5.03 percent versus 44.42 ± 5.18 percent, p < 0.05). The laser Doppler evaluation revealed significantly increased blood flow in the proximal two-thirds of the flap in the treatment group compared with the control group (p < 0.05).
Conclusion: Dimethyloxalylglycine treatment significantly increases VEGF and HIF-1α expression in endothelial cell cultures and enhances skin flap survival in vivo in a rat model.
Bern, Switzerland; and Bethesda, Md.
From the Departments of Plastic, Reconstructive, and Hand Surgery and Intensive Care Medicine, University Hospital (Inselspital) and University of Bern, and the Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health.
Received for publication November 17, 2010; accepted February 8, 2011.
Disclosure: The authors have no financial interest in any of the products mentioned in this article.
Maziar Shafighi, M.D., University Clinic for Plastic and Hand Surgery, University Hospital Inselspital, 3010 Bern, Switzerland, email@example.com,