C57BL/6 male and female mice were divided into four different groups and each group received their respective treatment 24 hours and 3 hours prior to, and 24 hours after a single fraction of 19.75 Gy of WAI. A) Fluorescent beads (F13083 FluoSpheres™ Polystyrene Microspheres, 1.0 μm, red fluorescent (580/605), for tracer studies) were administered 3 hours prior to sacrifice on days 2 or 5. (n = 5) (t-Test: paired two samples for means). B) Immunostaining, as described in the methods, for ICAM levels in intestine at day 5 after 15.75 Gy WAI. Blue color is DAPI, red is I-CAM C) Quantitation of I-CAM. D) Immunostaining for levels of occludin at day 5 after 15.75 Gy WAI (x40 magnification). E) Quantitation of occludin in intestine (x 40 magnification). For quantification in Fig. 3C and 3E, 30 microscopic fields were scored per mouse with 5 mice per group. The percent positive cells was based on scoring 1000 cells per mouse for 5 mice per data point.