Dermal glycosaminoglycan concentration throughout hair growth cycle of rats.

The dermal glycosaminoglycan (GAG) content of rats was measured quantitatively after plucking hair from the backs of the animals, which reinitiates their hair cycle. Mast cells present around the hair follicles were counted at each stage of the hair cycle and compared with the amount of GAG in the skin. GAG reached its peak on the 6th day of the anagen stage and decreased during the catagen stage. In the telogen stage, it was about the same as it had been in the catagen stage. The same pattern was noted for the number of mast cells. The 0.5 M fraction in Dowex-1 column chromatography proved to be hyaluronic acid and its concentration throughout the hair growth cycle showed strong parallels to that of total dermal GAG.