Rat Hair Follicle Growth In Vitro

The study investigated the growth of rat pelage hair follicles in vitro, using follicles isolated from 8-12-day-old rats and maintained in a supplemented medium. Over 48 hours, a significant increase in hair follicle length was observed, attributed to the production of a keratinized hair shaft. Initially, thymidine uptake was concentrated in the matrix cells near the dermal papilla, but this decreased after 72 hours as the dermal papilla rounded. While fetal calf serum, epidermal growth factor, and TPA stimulated thymidine and leucine uptake, they inhibited follicle elongation. Insulin-like growth factor-1 did not affect elongation or thymidine uptake but increased leucine uptake. Transforming growth factor-beta 1 inhibited both thymidine uptake and follicle elongation.