Ageing in skin microcirculation. Histology studies on paraffin-embedded sections (5 μm thick) of formalin-fixed skin of healthy subjects. Masson's trichrome staining shows collagen distribution (blue staining), around microvessels, in young (A) and old dermal skin (B). PAS staining shows hyaline deposits (pink staining), around microvessels, in young (C) and old dermal skin (D). CD31 immunostaining of young (E) and old dermal skin (F) showing the descrease of capillaries associated with ageing process. α-SMA immunostaining of young (G) and old dermal skin (H) showing the proliferation of VSMCs around aged microvessels. Magnification 40×.