Expression of Basement Membrane Components Through Morphological Changes in the Hair Growth Cycle

The study examined the expression of fibronectin and other basement membrane components during the hair growth cycle in rats. It was found that fibronectin levels varied significantly, being prominent in the dermal papilla matrix and basement membranes during the anagen (growth) phase, diminishing in the catagen (transitional) phase, and minimal in the telogen (resting) phase. The onset of anagen was marked by a significant increase in fibronectin, particularly around the dermal papilla, and was associated with cell division and follicle elongation. Immunoelectron microscopy confirmed these findings, showing fibronectin in vesicles near cell surfaces. Additionally, increased laminin and type IV collagen deposition in early anagen highlighted the role of basement membrane components in hair follicle morphogenesis.