RESUMEN
<p><b>OBJECTIVE</b>To investigate the effect of leptin on collagen systhesis in wounded rats.</p><p><b>METHODS</b>Thirty male Wistar rats, weight (180 +/- 20)g, were randomly divided into three groups (n = 10) by weight: normal depilation group, wound control group and leptin treatment group and ten rats were included in each group. A full-thickness defect measuring 2 x 2.5 cm was made in the back of rats in wound control group and leptin treatment group. Each wound in rats of leptin treatment group was applied topically with 0.1 ml leptin solution (2.0 microg leptin), daily for 7 days and that of wound control group with equivalent saline solution. All rats were killed and then granulation tissues samples and skin were collected to examine the synthesis of collagen.</p><p><b>RESULTS</b>Hydroxyproline content in granulation tissues of in leptin treatment group (33.92 +/- 3.09) mg/g were significantly increased than those in control group (29.55 +/- 3.59 mg/g, P < 0.05). The mRNA expressions of collagen I and III were significantly enhanced in leptin treatment group (0.96 +/- 0.09, 0.09 +/- 0.06) than those in control group (0.80 +/- 0.03, 0.08 +/- 0.03). The levels of type I and III collagen were significantly increased in leptin treatment group than those in control group.</p><p><b>CONCLUSION</b>Leptin applied topically can accelerate wound healing through enhancing gene expression of type I and III collagen and synthesis of collagen in wound tissue.</p>