Ação da l-arginina na evolução de retalhos cutâneos de ratos sob exposição à nicotina

Abstract

Objective: To evaluate whether treatment with L-arginine influences the healing of skin flaps in rats exposed to nicotine. Methods: 40 male Wistar rats weighing 142.4 ± 10.1 g were separated into four groups: GC: treatment with 7.4 pH phosphate buffer, submitted to skin flap and observation for ten days; GN: exposure to nicotine for four weeks, submitted to skin flap and observation for ten days; GA: treatment with 7.4 pH phosphate buffer for four weeks, submitted to skin flap and arginine treatment for ten days; GAN: exposure to nicotine for four weeks, submitted to skin flap and treatment with arginine for ten days. We evaluated: areas of necrosis, re-epithelialization, inflammatory reaction and formation of granulation tissue by HE stain; the total area of deposition and differentiation of collagens I and III by histometry with picrosirius staining; and the scar vascular density by immunohistochemical staining with monoclonal anti-CD34 antibodies. Results: The percentages of necrotic areas in GN and GNA were higher (p <0.001) than in GC and GA. In histological scores, collagen deposition, and the percentage of type I collagen, GA and GC were similar to each other (p> 0.05), but higher (p <0.001) than GA and GNA; as for vascular densities, they were lower in GN and GAN (p <0.001) than in GC and GA. Conclusion: Exposure to nicotine inhibited the effects of arginine and in unexposed rats there was induction of angiogenesis and improvement in the total collagen deposition in the skin flaps.