Single dose gamma irradiation induced angiogenesis in rat skin hair follicles

Background: Hair follicle cycling usually associated with prominent changes in skin vascularization; through follicular dermal papilla production of angiogenic factors. The early response of hair follicles to ionizing irradiation (IR) is induction of early anagen hair and appearance of new hair formation. Material and Method: Fifty rats were equally divided into 2 groups; control and γ-rays (10Gy) as a single dose, skin biopsy was taken from dorsum of the rat 72 hours after irradiation. Skin biopsy was examined histopathological and with immunohistochemical staining CD31. Blood samples were collected for biochemical analysis of Tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Malondialdehyde (MDA), Catalase (CAT) and Superoxide dismutase (SOD) Results: γ-rays produced epidermal thinning and dermal inflammatory cells together with dermal endothelial proliferation and new vessels formation around the hair follicle compared with control group as demonstrated by CD31 staining. Furthermore, there was a significant elevation of TNF-α, IL-1β and IL-6 levels compared to control group. Moreover, MDA levels increased significantly in γ-rays group and decreased significantly in control group, whereas CAT and SOD activities decreased in the γ-rays compared with the control group. Conclusion: The early effects of γ-rays on the skin could be beneficial and stimulatory to hair growth.