Fig. 3.

Per1 Increases the Enzymatic Activity of GPx to Scavenge ROS. A) Diurnal expression levels of Nampt in WT (black) and Per1^−/−(red) mice livers (left) and small intestines (right) determined by quantitative real-time RT-PCR (n = 4/time point/genotype). The white and black bar represents day and night, respectively. No significant difference was observed between WT and Per1^−/− mice. B) NAD⁺ levels in WT and Per1^−/− mice livers (left) and small intestines (right) at ZT1 and 13 (n = 4–5/time point/genotype). No significant difference was observed between WT and Per1^−/− mice. C, D) Peroxide levels of the livers (C) and intestines (D) from WT (left) and Per1^−/− (right) mice, samples were collected at ZT1 and ZT13, respectively (n = 5, 8 weeks old, *p < 0.05, **p < 0.01, night versus day group). E, F) Catalase activity of the livers (E) and intestines (F) from WT (left) and Per1^−/− (right) mice, samples were collected at ZT1 and ZT3, respectively (n = 5, 8 weeks old, *p < 0.05, **p < 0.01, night versus day group). G, H) GPX activity of the livers (G) and intestines (H) from WT (left) and Per1^−/− (right) mice, samples were collected at ZT1 and ZT13, respectively (n = 5, 8 weeks old, *p < 0.05, **p < 0.01, night versus day group). Throughout, all data were expressed as mean ± SEM, and male mice for all experiments were maintained on standard chow. Analyses were performed using two-tailed Student's t-test for C–H, two-way ANOVA for B. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)