The effects of carnitine on distally-burned dorsal skin flap: an experimental study in rats

Objective: In ischemia and burn injuries, there are major alterations threatening tissue survival. Increased energy flow requirements are among the major problems in these disorders. Carnitine is an endogenous cofactor, which has a regulatory action on the energy flow from different oxidative sources. The purpose of this study was to determine the effects of carnitine in an experimental flap model. Biochemically, nitric oxide (NO), malondialdehyde (MDA), and acetylcholinesterase levels, and histopathologically tissue examination under light microscope were studied. Methods: In the rat dorsal skin, a 10 cm×3 cm flap was marked. The most distal 3 cm×3 cm of the flap was burned to full-thickness. The dorsal flap was elevated, and sutured back to its original site. Sixteen rats were divided into two groups (a control (1) and a study group (2)), consisting of eight rats in each. While the animals in the control group were just followed, the animals in the study group were administrated carnitine with a dose of 100 mg/kg per day for 7 days. Results: At the end of the experiment: the mean surviving areas of the flaps were 15.22 cm2 (50.73%) in group 1, 20.53 cm2 (68.43%) in group 2, and the difference was statistically significant (P=0.008). In the analysis of blood samples; the mean levels of NO were 22.63 and 40.78 μmol/l; of MDA were 6.74 and 3.79 ng/ml; and of acetylcholinesterase were 136.14 and 222.85 U/l in groups 1 and 2, respectively. The differences in the levels of NO (P=0.001), MDA (0.027) and acetylcholinesterase (P=0.006) were statistically significant. Histopathological examination revealed a full-thickness muscle necrosis in addition to skin tissue in the control group, while healing tissue was present with marked cellularity including mixed inflammatory cells and fibroblast proliferation with an increased vascularity in the form of capillary budding in the study group. Conclusion: Carnitine has a positive effect in such a model, particularly in preventing the progressive effect of burn, and limiting the necrosis in the full-thickness burned part.