Exposure to gamma-rays at the telogen phase of the hair cycle inhibits hair follicle regeneration at the anagen phase in mice

The study investigated the effects of gamma-ray exposure on hair follicle regeneration in C57BL/10JHir mice during the telogen phase of the hair cycle. The results showed that gamma-ray irradiation led to decreased hair follicle density and the formation of curved hair follicles during the subsequent anagen phase. Additionally, anomalies such as white hair and hypopigmented hair bulbs were observed, indicating damage to stem cells and progenitors for keratinocytes and melanocytes. The severity of these effects was dependent on the dose of gamma-rays, suggesting that gamma-ray exposure during the telogen phase adversely affected the structure and pigmentation of regenerated hair follicles.