低频电磁场影响毛囊生长及KGF表达的实验研究

目的　观察低频电磁场（Low frequency electromagnetic field, LFEMF）对毛囊生长期中再生毛囊的形态学及该过程中角质化细胞生长因子（Keratinocyte growth factor,KGF）表达的影响。 方法　选用雌性C57BL/6成年鼠制作毛囊生长期模型,随机分为对照组和LFEMF组。LFEMF组采用50 Hz、5 mT磁场,30 min/d,连续作用16 d。取两组小鼠脱毛处的全层皮肤,HE染色法观察毛囊生长期中毛囊形态学的改变,荧光定量PCR法和Western-blot检测KGF表达情况。  结果　HE染色显示：3 d时,对照组中未见球状基质包绕毛乳头, LFEMF组球状基质部分包绕毛乳头,毛乳头上部有黑色素形成;9 d、16 d时,LFEMF组中毛囊的长度显著增加（P < 0.05）。荧光定量PCR及Western-blot检测结果表明LFEMF组较对照组的KGF基因转录水平及蛋白水平均上调。  结论　LFEMF能促进毛囊的生长,其机制可能与KGF的分泌增加有关。

The study of effects of low frequency electromagnetic field on the regeneration of hair follicles and expression of KGF in the anagen phase

Objective　To observe the effects of low frequency electromagnetic field on the growth of hair follicles and expression of keratinocyte growth factor in the anagen of the hair follicle.　Methods　The female C57BL/6 adult mice were selected to make the model of the anagen of the hair follicle, and randomly divided into the control group and the low frequency electromagnetic field group which was exposed to 50Hz、5mT electromagnetic field,30min/d, for 16d.After being exposed to the low frequency electromagnetic field for D3 , D9 and D16, the full-thickness skin of the hair removal site was used to detect the changes of morphology of the hair follicle and expression of keratinocyte growth factor in the anagen of the hair follicle. Results    Hematoxylin-eosin staining results showed that: at 3 d,Hair bulb partially surrounded the dermal papilla, and there was melanin above the dermal papilla in the low frequency electromagnetic field group ;at D 9 and D16,the length of the regeneration of hair follicle in the low frequency electromagnetic field group was increased. Fluorogenic quantitative PCR and Western-Blot analysis showed that the gene and protein expression of keratinocyte growth factor in the low frequency electromagnetic field group was significantly up-regulated compared with the control group (P<0.05).　Conclusions　The result showed that the low frequency electromagnetic field may promote the secretion of keratinocyte growth factor to advance the growth of hair follicles in the anagen of the hair follice.