Fig. 6.

Immunolocalization of SOD1 (red) in the small intestine after acute whole-body irradiation with 0 Gy and 8.5 Gy. Sections in column 1 were stained with Sytox Green (nuclear stain). Column 3 represents merged images from columns 1 and 2, while column 4 depicts staining intensity where blue = low, green = modest, yellow = high and red = highest intensity. Sections from unirradiated mice with primary antibody (row 1, panels A – D) and without (row 2, panels E – H). Irradiated mice with primary antibody (row 3, panels I – L) and without (row 4, panels M – P). SOD1 expression is greater in irradiated mice (compare panels B, C with J, K), confirming western blots in Fig. 4. Control panels H and P show no difference in intensity of staining of cytosol and nuclei along the crypt-villus axis when no anti-SOD1 is present. Before irradiation, endogenous SOD1 expression seems already greater in the crypt (top right, c) as opposed to upper villus (v) regions (panel D). After irradiation, there is a dramatic increase in SOD1 throughout the mucosa, and little increase in SOD1 in the submucosal and muscle layers (panel L). SOD1 expression seems greatest in the crypt region (c, panel, L) of intestines from irradiated mice.