P3 HUMAN HAIR GROWTH EX VIVO IS CORRELATED WITH IN VIVO HAIR GROWTH RATE: SELECTIVE CATEGORIZATION OF HAIR FOLLICLES FOR MORE RELIABLE HAIR FOLLICLE ORGAN CULTURE
Kwon OS1, Oh JK2, Kim MH2, Park SH2, Cho KH1, Eun HC1, Kim KH1
1Department of Dermatology, Seoul National University College of Medicine, Institute of Dermatological Science, Seoul National University Hospital, Seoul, Korea
2Rich Hair Clinic, Seoul, Korea

Of the numerous assays used to assess hair growth, hair follicle organ culture model is one of the most popular and powerful in vitro systems. Changes in hair growth are commonly employed as a measurement of follicular activity. Hair cycle stage of mouse vibrissa follicles in vivo is known to determine subsequent hair growth and follicle behavior in vitro and it is recommended that follicles be taken at precisely the same cyclic stage. This study was performed to evaluate whether categorization of human hair follicles by the growth rate could be used to select follicles of the defined anagen stage for more consistent culture. Occipital tissue samples were obtained from three subjects two weeks later after hair bleaching. Hair growth and follicle length of isolated anagen VI follicles were measured under a videomicroscope. Follicles were categorized into four groups according to hair growth and some were cultured ex vivo for 6 days Follicles showed considerable variations with respect to hair growth and follicle length, however these two variables were relatively well correlated. Hair growth in culture was closely related with hair growth rate in vivo. Selection of follicles at a defined stage based on hair growth rate would permit a more reliable outcome in human hair follicle organ culture.