The Immunohistochemical Changes of Skin During Hair Follicle Cycle After Depilation in Mice

The study examined the histological and immunohistochemical changes in the skin of C57BL/6N mice during the hair follicle cycle after depilation. Researchers observed changes in skin thickness, mast cell numbers, and cytokine activity at various stages post-depilation (1, 3, 5, 10, 14, 17, and 21 days). Skin thickness increased from telogen to day 14, while mast cell numbers decreased initially and then increased by day 14. Cytokine activity, including PKC-α, c-kit, and VEGF, showed mild staining early on but increased significantly by days 17 and 21. Brdu labeled cells were heavily stained in the bulge, epidermis, and connective tissue, indicating active cell proliferation. These findings suggested that hair follicle growth was associated with increased mast cell counts, skin thickness, and cytokine activity, highlighting the dynamic changes in skin structure and function during hair regrowth.