Figure 2: Effects of UVA irradiation on the collagen I and MMP-1 expressions in the skin. Six hours after the final UVA irradiation of the dorsal skin in the C57BL/6j and gp91phox-/- mice, the animals were sacrificed, and dorsal skin specimens were frozen, cut into thin sections and stained according to routine histological methods. The data show one typical experiment from 10 animals (Scale bar=100 μm).