RESUMO
BACKGROUND: Diabetes is associated with endothelial dysfunction and impaired wound healing. The amino acid L-arginine is the only substrate for nitric oxide (NO) synthesis. The purpose of this study was to compare the topical versus systemic L-arginine treatment on total nitrite (NOx) and vascular endothelial growth factor (VEGF) concentrations in wound fluid and rate of wound healing in an acute incisional diabetic wound model. MATERIALS AND METHODS: A total of 56 Sprague-Dawley rats were used of which 32 were rendered diabetic. Animals underwent a dorsal skin incision. Dm-sys-arg group (N = 8, diabetic) and Norm-sys-arg group (N = 8, normoglycemic) were gavaged with L-arginine. Dm-sys-control group (N = 8, diabetic) and Norm-sys-control group (N = 8, normoglycemic) were gavaged with water. Dm-top-arg group (N = 8, diabetic) and norm-top-arg group (N = 8, normoglycemic) received topical L-arginine gel. Dm-top-control group (N = 8, diabetic) received gel vehicle. On the day 5 the amount of NOx in wound fluid was measured by Griess reaction. VEGF/total protein in wound fluids was also measured on day 5 using enzyme-linked immunosorbent assay. All wound tissue specimens were fixed and stained to be evaluated for rate of healing. Data were analyzed using SPSS software (version 18.0, Chicago, IL, USA) through One-way analysis of variance test and Tukey's post-hoc. RESULTS: In dm-sys-arg group, the level of NOx on day 5 was significantly more than dm-top-arg group (P < 0.05). VEGF content in L-arginine treated groups were significantly more than controls (P < 0.05). Rate of diabetic wound healing in dm-sys-arg group was significantly more than dm-top-arg group. CONCLUSION: Systemic L-arginine is more efficient than topical L-arginine in wound healing. This process is mediated at least in part, by increasing VEGF and NO in the wound fluid.
RESUMO
We aimed to investigate whether oral administration of captopril modulate wound healing, nitric oxide (NO), and vascular endothelial growth factor (VEGF) concentration in wound fluid of diabetic rats. 48 male Sprague-Dawley rats were divided in four groups (n = 12). The 36 rats were rendered diabetic by streptozotocin. The animals of the first and second groups received 25 and 50 mg/kg/day captopril, respectively, (DM-cap25 and DM-cap50). The animals of the third group were treated by distilled water (DM-control). Control rats had no intervention. The wound fluid level of NO and VEGF were measured. Wound specimens were investigated histopathologically. At the 5th day, there was significantly more NO(x) in wound fluid of DM-cap25 compared to other groups. At the 7th day, both captopril-treated groups had more NO(x) in wound fluid compared to other groups. At the 11th day, both captopril-treated groups had more NO(x) in wound fluid compared to DM-control group. VEGF concentration was significantly higher in both captopril-treated groups versus DM-control group (P < .05). There were significant higher wound healing scores in captopril-treated groups compared with DM-control group (P < .05). These results suggest that captopril might be useful in diabetic wound healing.
