Immunostaining and cellular localization of MMP-2 and MMP-9 in arterial sections (position 3) 1 week after electric injury in MMP-3^+/+ mice. Single immunostaining was performed for MMP-2 or MMP-9 (appearing red) and for α-actin or Mac-3 (appearing green). Cells in which MMPs and α-actin or Mac-3 are colocalized appear yellow. The elastic membranes are visualized by their autofluorescence. The arrows and arrowheads indicate the internal and external elastical lamina respectively (original magnification ×480).