Objective: To investigate the dose-effect of dietary L-arginine supplementation on burn wound healing in rats.
Methods: 218 Sprague-Dawley rats (weighing 200-250 g) were subjected to 10% deep partial thickness scald burns and were randomized into six groups. Groups A, B, C, D, E and F received 800, 400, 200, 100, 50 and 0 mg.kg-1.d-1 L-arginine in the form of L-arginine solution, and 0, 727, 1090, 1272, 1364, and 1454 mg.kg-1.d-1 glycine, respectively. Each solution was isonitrogenous. The times of completing re-epithelization were recorded. The contents of hydroxyproline (OHP) in burn wound area (index of reparative collagen synthesis) and the ratios of type I and type III collagen were examined in all groups.
Results: The times of completing re-epithelization (day) in groups A, B, C, D, E, and F were 24.9 +/- 1.95, 22.5 +/- 2.0, 20.2 +/- 2.4, 23.5 +/- 2.6, 23.8 +/- 3.5, and 24.7 +/- 2.3, respectively. The contents of hydroxyproline in groups B, C and D were higher than in groups A, E and F on PBD 7, 10 and 14. The ratios of type I and type III collagen in groups B, C and D were lower than in groups A, E and F.
Conclusion: Oral dietary L-arginine supplementation from 100 mg.kg-1.d-1 to 400 mg.kg-1.d-1 shortened the times of re-epithelization, increased amounts of hydroxyproline, and accelerated the synthesis of reparative collagen in burn rats.