毛乳头在毛囊生长周期中的变化和作用

目的 了解人毛乳头结构在毛发生长周期中的变化及其对毛发生长的调控作用.方法 将整形手术后取下的头皮在无菌条件下分离成游离的毛囊,在Williams E培养基中培养;通过横断毛囊和完整毛囊的培养来观察毛囊的生长状况和处于不同生长周期的毛囊的毛乳头结构变化.结果 分离后的完整毛囊在Williams E培养基中平均可继续生长12 d,平均生长速度为每天0.2～0.3 mm;静止期或生长初期毛囊的毛乳头呈圆形贴在毛球底部,快速生长的毛囊毛乳头变长呈锥形,结构疏松,与毛根紧密相接,当毛囊进入衰退期直至停止生长后毛乳头萎缩变小,并与毛根逐渐分离.在低位横断毛囊,毛囊可再生毛球并继续生长,但生长速度减慢;在高位横断毛囊,毛囊不能继续生长.结论 毛乳头在毛发生长周期中不断变化,生长期毛乳头体积增大,与毛母质联系紧密,它在毛囊的生长和生长周期中起着不可缺少的调控作用.

Changes of hair papilla and its role in the growth cycle of the hair follicles

OBJECTIVE: To investigate the changes of hair dermal papilla and its regulatory role in the growth cycle of the hair follicles. METHODS: Single hair follicles were isolated from surgical specimens of human scalp and cultured in Williams E medium. The growth of the hair follicle was measured and the morphology and structure of the dermal papilla in the different growth cycles were observed continuously. RESULTS: The hair follicle could grow in the medium for 12 days at the average growth rate of 0.2-0.3 mm/day. The flat and round dermal papilla lay at the bottom of the hair bulb in the telogen and anagen stages. In the hair follicle with accelerated growth, the dermal papilla became elongated, loosened, and closely adhered to the hair matrix. In the catagen stage the dermal papilla shrunk, and became separated from the hair matrix. A new hair bulb was regenerated when the hair follicle was transected at a low level. The hair follicle stopped growing after transection at a higher position. CONCLUSION: The hair dermal papilla is the essential for hair follicle growth, and plays an important role in regulating the hair growth cycle.