Cell Kinetics of the Human Hair Follicle

The study from 1988 explored the cell kinetics of the human hair follicle, focusing on the complex structure and the control of growth and differentiation within this tissue. The follicle's base is divided into keratinocytes of the hair matrix and the dermal papilla, which includes fibroblasts and a microvascular system. The dermal papilla significantly influences follicle keratinocytes, which rapidly cycle and migrate to form the hair fiber and inner root sheath during the anagen phase. Despite the identification of up to seven differentiated phenotypes in these cells, the mechanisms controlling their differentiation and migration were not understood. The study suggested that defining proliferation rates in different tissue parts could help identify growth regulation targets and understand the coordination of proliferation and differentiation, while also cautioning about the potential misapplication and misinterpretation of cell kinetics techniques.