Figure 5.

Overexpression of SIRT1 enhanced the reproductive response to CR. Data for N-MUT mice are shown in red, in white for WT littermates, and green for N-OX mice in green. Estrous cycles were assessed by vaginal lavage in female mice during the 8 wk of CR. Data are reported as mean ± SEM. (A) Average number of d spent in met/diestrus, proestrus, or estrus during the four 2-wk stages of increasing CR for each genotype of the estrous cycle during the 6-wk cycling (n = 6 for N-MUT; n = 14 for WT; n = 5 for N-OX). Two-way ANOVA indicated a significant CR effect (P < 0.0001) and significant interaction of CR and genotype (P = 0.003) for met/diestrus, a CR effect (P < 0.0001) for proestrus; and a genotype effect (P = 0.017), a CR effect (P < 0.0001), and a significant interaction of CR and genotype (P = 0.011) for estrus. (B) LH levels during the four stages of CR (n = 6 for N-MUT; n = 12 for WT; n = 5 for N-OX). No significant differences were observed. (C) FSH levels during the four stages of CR (n = 6 for N-MUT; n = 12 for WT; n = 5 for N-OX). Two-way ANOVA indicated significant genotype (P = 0.022) and CR (P = 0.002) effects but no significant interaction. (D–F) Estradiol, progesterone, and testosterone levels before and after CR (n = 3 for N-MUT; n = 3 for WT; n = 3 for N-OX. Each sample was pooled from two animals). Two-way ANOVA indicated significant genotype (P = 0.0004) and CR (P = 0.0033) effects for estradiol, a CR effect (P = 0.0055) for progesterone, and genotype (P = 0.015) and CR (P = 0.019) effects for testosterone. No significant interactions of CR and genotype were observed. *P < 0.05, **P < 0.01, *P < 0.001, ****P < 0.0001 (post hoc testing). Met, metestrus.