The Experimental Study:the Melasma Models Of Mouse Treated By Pulsed Dye Laser

Purpose：To observe the effect of PDL treating melasma models of mouse，detecting theinteractions between the cutaneous vasculature and melanocytes in melasma, toexplore the mechanism of PDL treating melasma.Methods：Choose40female Kunming mice which were divided randomly into treatinggroup and normal group and wipe off the hair of its back about2x3cm. The treatinggroup mice were injected of progesterone and gave them UVB radiation of320nmfor45days. To get the melasma models of mouse. And determine the SODactivity,the quantity of MDA in the mice skin, finding that this kind of establishingmelasma model can heighten MDA,depress SOD, and increase melanocytes of skin.After the success of establishing the models, they were devided into three groups,group A（the control group）, group B（the one-time PDL treatment group）, group C（the two-time PDL treatment group）.Then the experimental zones were treated byPDL. Skin tissue samples were collected to make histopathologic examination atbefore laser treatment and every time one week after the PDL treatment. HE dyingshow the changes of epidermis, ElivisionTMplus immunohistochemical method withHMB45was used to mark the melanin granule in epidermis. Also CD34was used tomark the cutaneous vasculature. The changes of the melanin granule and cutaneousvasculature were analyzed using image analytical method. Put the data intocomputer, statistical analyse using SPSSl3.0, p<0.05with statistical significance.Results：1.27mice were survival. The SOD activity was decreased much more and thequantity of MDA was increased much more than that of the normal group.ElivisionTMplus immunohistochemical method with HMB45show that the melaningranule was more than that of the normal group. 2. Using PDL on experimental zones of the melasma models, after one week,skin tissue samples were collected to make histopathologic examination. The resultwas that comparing with the cutaneous vasculature of the control group，thecutaneous vasculature was decreased sharply (P <0.05). And at the same time, themelanin granule in epidermis was decreased obviously(P <0.05). The cutaneousvasculature and the melanin granule of the two-time PDL treatment group weredecreased more obviously.Conclusion：1.The combination of injecting progesterone and exposing to UVB can buildmelasma mouse model successfully.2.The cutaneous vasculature of the melasma models of mouse lesions was muchmore than that of the normal skin.3.PDL treatment on the melasma model zones by targeting the cutaneousvasculature is effective. The hemoglobin become solidification after absorbing heat.The heat can transfer to the nearby melanin cell which can induce cell apoptosis. Itconfirms that PDL can treat melasma with increased cutaneous vasculature.