D980-nm半导体激光对大鼠皮肤溶脂嫩肤作用机制初步研究

Mechanism of lipolytic and smooth effects of D980-nm laser treatment on skin tissue in rats

目的初步探讨D980-nm半导体激光对SD大鼠皮肤溶脂嫩肤作用机制,分析不同治疗频次的差异。方法12~14月龄清洁级雄性SD大鼠18只,体质量400~450 g。以大鼠脊柱为分界线,左侧皮肤作为激光照射实验侧,右侧皮肤作为自身正常对照侧。实验动物随机分为3组(n=6),实验侧(分别为A、B、C组)采用D980-nm半导体激光仪以脉冲模式,能量密度20 J/cm^2、功率8 W、脉冲宽度20 ms、脉冲频率40 Hz,分别皮下照射1、2、3次作为1个疗程,每次间隔5 min,每个疗程间隔1周,共4个疗程。对照侧(分别为A1、B1、C1组)不作激光处理。第4个疗程结束后1周取材,行HE染色及免疫组织化学染色,观察激光照射前后大鼠皮肤组织结构变化,测量真皮厚度,计数成纤维细胞及TGF-β_1、b FGF阳性细胞。结果与A1、B1、C1组相比,D980-nm半导体激光照射后A、B、C组大鼠皮肤组织结构均改善明显,脂肪细胞减少,局部可见小血管形成,成纤维细胞增多,胶原纤维束增多、变粗且排列紧密、规则,真皮厚度、成纤维细胞以及TGF-β_1、b FGF阳性细胞均显著增加,比较差异有统计学意义(P<0.05)。随激光治疗频次的增加,以上指标均逐渐增加,C组优于A、B组,比较差异有统计学意义(P<0.05)。结论D980-nm半导体激光治疗对大鼠皮肤有明显的溶脂嫩肤作用,并与激光治疗频次密切相关,其溶脂嫩肤作用与激光的组织效应和细胞效应相关。

Objective To determine the efficacy of D980-nm laser in dissolving fat and renewing skin, and to explore the clinical application of D980-nm laser in reconstruction ofphotodamaged skin. Methods Eighteen 12-14 month-old male Sprague-Dawley rats, weighing 400-450 g, were randomly divided into 3 groups （n=6）. The rat skin at the left side was exposed to D980-nm laser irradiation at a density of 20 J/cm^2, a power of 8 W, a pulse width of 20 ms, and a pulse frequency of 40 Hz for 1 time （group A）, 2 times of 5-minute interval （group B）, and 3 times of 5-minute interval （group C） as a treatment course, for 4 treatment courses with an interval of I week; the other side of the skin was not treated as the control groups （groups A1, B1, and C1, respectively）. After 8 weeks, the skin was harvested for HE staining and immunohistochemical staining to observe the structure changes of skin, to measure the dermal thickness, to count the number of fibroblasts, and detect the expressions of transforming growth factor [31 （TGF-β1） and basic fibroblast growth factor （bFGF）. Results Compared with groups A1, B1, and C1, the skin structure was significantly improved in groups A, B, and C. After D980-nm laser irradiation, the number of fat cells decreased; local angiogenesis was observed; the total number of fibroblasts and fibers increased; the collagen fiber had large diameter, and arranged closely and regularly; the dermal thickness and the number of the fibroblasts increased; and the expressions of TGF-β1 and bFGF were significantly enhanced, showing significant differences （P〈0.05）. With increased D980-nm laser irradiation times, the above indexes increased, showing significant differences between group C and groups A, B （P〈0.05）. Conclusion D980-nm lasertreatment has lipolytic and tender effect on the skin, and the frequency of the treatment is an important factor in skin renewal.