(a)
(b)
(c)
Figure 4: The interaction of VE deficiency and radiation measured by the mean of SOD, MDA, and AGE, respectively, on 66th day. The black dots indicate the mean of the corresponding index. The solid lines represent VE deficiency. The dotted lines represent radiation, and the discontinuous lines represent experimental control. As shown in (a), the dotted line is downward from radiation “no” to “yes,” which indicates radiation decreases the SOD activity comparing to the experimental control. The solid line slopes more than that of the dotted line, which means VE deficiency makes radiation more seriously lower the SOD activity. The similar analysis is worth applying to (b) and (c). With the two unparalleled lines (the solid and the dotted) in each graph, it is shown that the effect differences in VE deficiency depend on the presence of radiation, which gives a clue to the existence of interaction between VE deficiency and radiation and implies that the combination of these two factors could cause a magnified effect of oxidative stress.