Abstract: Objective To investigate the effects of epidermal growth factor (EGF) on hair follicle growth. Methods Cultured human hair follicles were divided into two groups:EGF-treated group (EGF 20 ng/mL) and control group. The length and morphology of follicles were measured by inverted microscope daily. ³H-leucine incorporation and histologic studies were applied. Results The rates of hair shaft and hair follicle elongation significantly increased in the EGF-treated group during day 1 to day 3 in comparison with the control group. Histologically, the cells of the lower outer root sheath were thickened and club hair-like structure was formed. ³H-leucine incorporation showed that the radioactivity in hair follicle epithelium was higher in EGF-treated group (370 c/min)than that in control group(271.14 c/min) (P<0.05). No difference was found in terms of the radioactivity in hair shaft between EGF-treated group(173.19 c/min) and control group(158.49 c/min). Conclusion It is suggested that EGF might stimulate the growth of hair follicle epithelium, and induce anagen transforming into catagen prematurely.

Key words: Hair follicle, Organ culture, Epidermal growth factor-urogastrone