The Lipid Distribution in the Human Hair Follicle

Lee, Sang Hoon; Lee, Eun Young; Kim, Young Hee; Lee, Won Soo

Abstract

BACKGROUND
It has recently been demonstrated that human hair also contains lipids. On the hair surface, the lipid layer is attached to the outer surface of hair covalently bonded to hair proteins. However, there have been no reports on lipid distribution in human hair follicles yet. OBJECTIVE: The purpose of this study was to demonstrate the lipids of the hair follicle and its distribution and also to examine the lipid composition of the hair follicle. MATERIAL AND METHODS: Follicles were obtained from the occipital region of the scalp which were not under the influence of anagen hormone. The specimens were stained using typical methods of oil red O, Holzinger's copper-rubeanic acid modification, perchloric acid-naphthoquinone reaction. RESULTS: Oil red O staining that could be used to stain all lipids was well detected in the area, Henle's layer of inner root sheath (IRS), IRS cuticle, and hair cuticle, which were keratinzed earlier in the hair follicle. The hair cuticle and the IRS were stained dark green on Holzinger's copper-rubeanic acid modification that could be used to stain free fatty acids. The IRS was stained gray-blue on perchloric acid-naphthoquinone reaction method that could be used to stain cholesterol and its esters. CONCLUSION: The present results demonstrate that the lipids of the hair follicle are located on the hair cuticle and the keratinized area of the IRS. They can act as a barrier of the hair follicle.