Figure 1.
Effects of food volume and daily meal on the phase of the liver circadian clock.
A: Mice were administered a diet tablet containing 0–0.85 g/10 g BW of the control AIN-93M diet for 2 days after 24-h food deprivation. Diet volume of 0.3 g/10 g BW for 2 days (0.3+0.3-g group); 0.6 g/10 g BW for 2 days (0.6+0.6-g group); or 0.6 g/10 g BW on the first day and 0.85 g/10 g BW on the second day (0.6+0.85-g group) was administered. B: Diets of 0.6 g/10 g BW on the first day (1-day group); 0.6 g/10 g BW on the first and 0.85 g/10 BW on the second day (2-day group); or 0.6 g/10 g BW on the first day followed by 0.85 g/10 g BW for the next 3 days (4-day group) was administered. Some mice were permitted free access to the control diet during ZT6–ZT10 (4 h) for 14 days (14-day group). The values indicate the mean±SEM. The horizontal axis indicates the projected zeitgeber time (pZT) at the peak of the bioluminescence rhythm. ZT0 is light-on time in the housing room prior to sacrifice of the mice. Fisher's PLSD test: #P<0.05, ##P<0.01 (vs. free feeding). *P<0.05 (vs. fasting). Two kinds of control experiments were prepared: Free feeding (open circle); fasting, 2-day fast (rhombus). The numbers in the parentheses indicate the number of tested mice.
Figure 2.
Effects of complete substitution by single nutrient components in the AIN-93M diet on the phase of the liver circadian clock and relative blood glucose value.
A: Percent component of each nutrient in AIN-93M. Other contents were 3.5% AIN-93 mineral mixture, 1% AIN-93 vitamin mixture, 0.25% choline bitartrate, and 0.0008% tert-butyl hydroquinone. Substituted components are shown by the white column segments. B: Mice were administered a diet tablet containing 0.6 g/10 g BW of each nutrient on the first day and 0.85 g/10 g BW of each nutrient on the second day after 24-h food deprivation. Some mice were administered 0.3 mL of soybean oil on the first day and 0.43 mL of soybean oil on the second day after 24-h food deprivation. The values indicate the mean±SEM. The horizontal axis indicates the pZT at the peak of the bioluminescence rhythm. Fisher's PLSD test. *P<0.05 (vs. fasting); fasting, 2-day fast # P<0.05, ## P<0.01 (vs. AIN-93M). C: Time course of the blood glucose level after oral injection of 0.03 g/10 g BW of AIN-93M, 100% cornstarch, 100% casein, 100% sucrose, or 100% glucose or 0.015 mL/10 g BW of 100% soybean oil. For the control, 0.33 mL/10 g BW of water was administered. The vertical axis indicates the content of glucose (mg/dL). Symbol color of each treatment is same as column color in part D. D: Relative blood glucose value (% of blood glucose level produced by 100% glucose) of each nutrient group. This value was calculated by the following formula: 100× [AUC (area under the blood glucose concentration-time curve) during 2 h after each nutrient administration/AUC during 2 h after 100% glucose administration]. The values indicate the mean±SEM. Fisher's PLSD test. **P<0.01 (vs. water). # P<0.05 (vs. AIN-93M). The numbers in the parentheses indicate the number of tested mice. E: Percent component of each nutrient in AIN-93M. Substituted components are shown by the white column. F: Effect of combination of 100% glucose, 86% glucose +14% casein, 96% glucose +4% soybean oil, 95% glucose +5% cellulose, or 95.5% glucose +3.5% AIN-93 mineral mixture and 1% AIN-93 vitamin mixture on the liver circadian clock. Feeding schedule was the same as in Fig. 2B. The values indicate the mean±SEM. The horizontal axis indicates the pZT at the peak of the bioluminescence rhythm. Fisher's PLSD test. *P<0.05 (vs. 100% glucose). # P<0.05 (vs. AIN-93M). The numbers in parentheses indicate the number of tested mice. We used the same data of fasting and AIN-93M as mentioned in Fig. 1 to produce Fig. 2.
Figure 3.
Effects of partial substitution by starch/sugar in the AIN-93M diet on the phase of the liver circadian clock and relative blood glucose value.
A: Percent of each nutrient component in AIN-93M. The ‘other’ category comprised 3.5% AIN-93 mineral mixture, 1% AIN-93 vitamin mixture, 0.25% choline bitartrate, and 0.0008% tert-butyl hydroquinone. Substituted components are shown by the white column segments. B: Mice were administered a diet tablet containing 0.6 g/10 g BW of the substitute diet on the first day and 0.85 g/10 g BW of the substitute diet on the second day after 24-h food deprivation. Nutrient components of cornstarch, gelatinized cornstarch, and sucrose were replaced with glucose, sucrose, fructose, or polydextrose. The horizontal axis indicates the pZT at the peak of the bioluminescence rhythm. Fisher's PLSD test. *P<0.05 (vs. fasting). # P<0.05 (vs. glucose). C: Time course of the blood glucose level after oral injection of 0.03 g/10 g BW of each substituted nutrient. The vertical axis indicates the content of glucose (mg/dL). The values indicate the mean±SEM. Symbol color of each treatment is the same as column color in part D. D: Relative blood glucose value (% of glucose) of nutrient substituted group. Fisher's PLSD test. **P<0.01(vs. water). #P<0.05, ##P<0.01(vs. glucose). E: Percent component of each nutrient in AIN-93M. Substituted components are shown by white column. F: The component of 10% sucrose was substituted with 10% glucose, 10% fructose, or 10% polydextrose. The horizontal axis indicates the pZT at the peak of the bioluminescence rhythm. Fisher's PLSD test. *P<0.05 (vs. fasting). The numbers in parentheses indicate the number of tested mice. We used the same data for fasting and AIN-93M as mentioned in Fig. 1 to produce Fig. 3.
Figure 4.
Effects of the substitution of cornstarch in AIN-93M by gelatinized cornstarch (GCS) or high-amylose cornstarch (HACS) on the phase of the liver circadian clock and relative blood glucose value.
A: Percent component of each nutrient in AIN-93M. Substituted components are shown by the white column segments. B: Mice were administered a diet tablet containing 0.6 g/10 g BW of the substituted diet on the first day and 0.85 g/10 g BW of the substituted diet on the second day after 24-h food deprivation. The components of cornstarch and GCS in AIN-93M were replaced with GCS or HACS. The horizontal axis indicates the pZT at the peak of the bioluminescence rhythm. Fisher's PLSD test. *P<0.05 (vs. fasting). #P<0.05 (vs. GCS). C: Time course of the blood glucose level after oral injection of 0.03 g/10 g BW of each substituted nutrient. The vertical axis indicates the content of glucose (mg/dL). The values indicate the mean±SEM. Symbol color of each treatment is same as column color in part D. D: Relative blood glucose value (% of glucose) of the nutrient-substituted group. Fisher's PLSD test. **P<0.01 (vs. water), ##P<0.01 (vs. GCS). The numbers in parentheses indicate the number of tested mice. E: Percent component of each nutrient in AIN-93M. Substituted components are shown by white column segments. F: All nutrient components in AIN-93M were completely substituted with 100% cornstarch, 100% GCS, or 100% HACS. The horizontal axis indicates the pZT at the peak of the bioluminescence rhythm. Fisher's PLSD test. *P<0.05 (vs. fasting); fasting, 2-day fast # P<0.05, ## P<0.01 (vs. AIN-93M). The numbers in the parentheses indicate the number of tested mice. We used the same data of fasting or 100% cornstarch as mentioned in Fig. 2 to produce Fig. 4.
Figure 5.
Restricted feeding-induced anticipatory activity (FAA) produced by AIN-93M, 100% glucose, or 86% glucose +14% casein diet.
A: Examples of double-plotted actograms of free-feeding or restricted-feeding mice under LD cycle. Horizontal open and closed bars indicate the light and dark periods, respectively. Zeitgeber time (ZT) 0 indicates lights on and ZT12 lights off, under LD-cycle schedule. Blue area exhibits ZT3–ZT6 before restricted feeding for 2 days, and red area represents ZT3–ZT6 during restricted feeding for 2 days. Food was given at ZT6 for 2 days during red area after 24-h fasting. B: Percent change of anticipatory activity increase. Percent activity increase was calculated by the following formula: 100× (percent activity counts [ZT3–ZT6] of daily total activity during the 2-day restricted feeding schedule [red area]/those [ZT3–ZT6] during the 2-day free-feeding schedule [blue area]). The values indicate the mean±SEM. The numbers in parentheses indicate the number of tested mice. *P<0.05 from free-feeding schedule.