Effects of IGF-I and EGF on In Vitro Growth of Hair Follicles of Sheep

The study investigated the effects of IGF-I and EGF on sheep hair follicles cultured in vitro. It was found that 10 ng/mL IGF-I and 20 ng/mL EGF both stimulated hair follicle growth. IGF-I positively regulated follicle growth, while 20 ng/mL EGF accelerated the differentiation of external root sheath cells and induced an earlier transition from the growing to the recessing period. The combination of 10 ng/mL IGF-I and 20 ng/mL EGF further accelerated hair follicle growth.