Effects of L-arginine on percentage of healing in burns in rats

Nitric oxide [NO] is a free radical with a short half life and is recognized as an important mediator involved in various pathological and pathophysiological processes. It is produced by oxidation of L-arginine. There are many different reports about its beneficial effects in burns. The aim of the present study is to assess the effects of L-arginine [NO Precursor] and L-NAME [NO inhibitor] on epithelialization and precentage of healing of the burns in rats. 60 adult male rats with the weight of 250-270g were entered into this study. After induction of general anesthesia, a certain area on the back region was exposed to 95c water for 8 seconds in order to produce wet burns. Then the animals were divided into two equal groups randomly. Each group divided further into three sub-groups: control, L-arginin which received 100 mg/kg L-arginine intraperitonealy and L-NAME which received l0 mg/kg L-NAME. Injections in the first group performed on the first, third and fifth days and skin biopsies were taken on the seventh day after burn. Injections in the second group performed every other day from the first to the 13th day, and specimens were obtained on the 15th day. After staining the samples with H and E, the extent of epithelialization was evaluated. The percentage of wound healing was another index which was assessed by measuring the surface of the healed area on the fifth, tenth and 15th day after burn. The rate of epithelialization [new epiderm] from edge of intact skin in L-arginine group was higher than those of other groups. Also L-arginine group revealed a higher perecentage of healing than other groups but it was not statistically significant. In this study none of the groups showed complete wound closure but NO somewhat accelerated the wound healing process