病理性色素沉着通常在创伤、手术、日照等条件下发生, 临床首选方法为激光治疗, 虽疗效显著但存在色斑复发, 具体机制尚不清楚。本研究首次选用成年斑马鱼建立激光祛斑动物模型, 结果发现: 激光祛斑后斑马鱼皮肤重新出现色斑, 其灰度值、面积及分布与照射激光的能量密度和脉冲时间等参数显著相关; 色斑面积缩减在照射后第1、2天最显著, 复发在第5天最高; 高能量组在祛斑效应上总体不如低能量组, 且后者色斑复发也不显著; 色斑复发部位巨噬细胞迁移抑制因子(macrophage migration inhibitory factor,MIF)表达上调且与色斑复发程度成正相关。MIF对血管新生具有较强的促进作用, 故色斑复发可能与MIF上调引起的血管新生有关。以上研究结果提示, 祛斑效果皮秒激光(picosecond laser, 下文简称Ps激光)显著优于纳秒激光(nanosecond laser, 下文简称Ns激光), 低能量激光结合MIF表达调控可能有助于抑制祛斑后的血管新生, 从而降低色斑复发, 对激光祛斑的临床应用有直接的理论指导价值。

Pathological pigmentation usually occurs under the conditions of trauma, surgery, sunshine, etc. The clinical preferred method is laser treatment. Although the curative effect is significant, there is recurrence of pigmentation, under which the specific mechanism remains unclear. In this study, for the first time, the adult zebrafish was used to establish a laser ablation animal model. The results showed that pigments in zebrafish skin reappeared after laser ablation. And the gray value, area and distribution of reappeared pigments were highly related to energy density and pulse time of the irradiated laser. It is found that pigments area reduction was most significant on the first and second days after laser ablation, and recurrence effect become worst on the fifth day; The high energy density group was not as good as the low energy density group in the freckle effect, and pigmentation recurrence of the latter was not significant; The protein level of macrophage migration inhibitory factor(MIF)in laser ablation recurrence site was up-regulated and positively correlated with the degree of recurrence of pigmentation. MIF has a strong promoting effect on angiogenesis, so recurrence of pigmentation might be induced by up-regulation of MIF. The above results suggest that the freckle effect of Ps lasers is significantly better than that of NS lasers. Low-energy laser combined with MIF regulation may help to inhibit angiogenesis after laser ablation, thereby reducing pigment recurrence, which provides direct theoretical guidance for clinical application of laser ablation.