The effects of vasonatrin peptide on random pattern skin flap survival.

BACKGROUND: A lot of methods have been intensively investigated to improve random skin flap survival. Decreasing inflammation and alleviating tissue injury have been reported to be effective in improving survival ratio. Vasonatrin peptide (VNP) is a chimera of atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP). The current study demonstrates that VNP possesses the venodilating actions of CNP, the natriuretic actions of ANP, and the unique arterial vasodilating actions not associated with either ANP or CNP. However, its effects on skin flap survival have not been previously reported. METHODS: Sprague-Dawley rats, weighing 220 to 260 g, were randomly divided into 2 groups, namely, the VNP-treated group and the control group. Rectangular random dorsal skin flaps measuring 3 × 9 cm including the panniculus carnosus were elevated, then the flaps were sutured into their original places. In the VNP group, 0.1 mg/kg of VNP was administered intravenously (IV) after surgery and then daily for 3 days. In the control group, 1 mL/kg of saline was administered IV after surgery and then daily for 3 days. To observe the effects of VNP, blood perfusion, histopathological examination, the inflammatory mediators (tumor necrosis factor α, interleukin 1ß, and interferon γ), and biochemical analysis (malondialdehyde, glutathione, and myeloperoxidase) were detected and the flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area. RESULTS: The viability measurements showed the percentage of flap survival was increased in the VNP-treated group (76.53% ± 6.36%) as compared with the control group (61.12% ± 4.92%) (P < 0.05), and the histological and biochemical assays corroborated the data. The blood perfusion of flaps in the VNP-treated group was higher than the control group (P < 0.05). The inflammatory mediators (tumor necrosis factor α, interleukin 1ß, and interferon γ) were significantly lower in the VNP-treated group than the control group (P < 0.05). CONCLUSIONS: This study found that VNP, which could elevate the tissue blood perfusion and mitigate the tissue damage and inflammatory reaction, is associated with a higher percentage of survival random pattern skin flap area.

[Establishment of new vessels model by implantation of VEGF165 in mouse].

OBJECTIVE: To investigate the feasibility of establishing a murine new vessels model with Lentiviral vector (LVs) mediated human vascular endothelial growth factor-165 (pcDNA3.1/ VEGF165) gene. METHODS: Lentivirus plasmid carrying a human VEGF165 was constructed and was used to transfect mouse's NIH/3T3 cells. The NIH/3T3 cells with high secretion of VEGF were injected into the skeletal muscle of mouse to establish a mouse new vessels model by implantation of vascular endothelium growth factor (VEGF) gene. The external secretion of VEGF was measured with ELISA. Histological examination was carried out after injection. The expression of CD31 was assessed with immunohistochemical method. RESULTS: The lenti-VEGF165-EGFP was correctly constructed and confirmed by restriction endonuclease analysis, polymerase chain reaction and DNA sequencing analysis. Lentivirus plasmid carrying a human VEGF165 was constructed. lenti-VEGF165-EGFP was used to transfect mouse's NIH/ 3T3 cells, and human VEGF165 gene was assessed. NIH/3T3 cells mediated VEGF gene implantation can produce stable and effective mouse new vessels model. The external secretion of VEGF in peripheral blood was measured with ELISA. The legs became swollen in experimental group 14 d after injection. It found the cells expression of CD31 44 d after injection, and histological analysis showed the swollen tissue was composed of small new vessels. CONCLUSIONS: NIH/3T3 cells mediated VEGF gene implantation can produce stable and effective mouse new vessels model.