Fig. 5.

Single-amino-acid-diet, particularly cysteine, results in phase advance of liver circadian clock. (a) The left graph shows average relative waveforms of hepatic in vivo PER2::LUC bioluminescence in the Control and the Amino acids groups. The right graph shows the average peak phases of in vivo PER2::LUC rhythms. Control: n = 10; Protein: n = 9; Amino acids: n = 4. (b) Experimental schedule. The green arrows indicate oral administration time of 0.5% CMC (Control) or each of 20 single amino acids at ZT 5 for 3 consecutive days. The orange arrow indicates fasting. (c) Average peak phases of in vivo PER2::LUC rhythms in all groups. All groups: n = 4. (d) Phase-response curves following cysteine administration. Increased and decreased phase shifts indicate phase advances and delays, respectively. Control groups at all time points: n = 4; Cysteine groups at ZT 1, 9, 13, and 21: n = 5; Cysteine group at ZT 5: n = 4. Data are presented as the mean ± SEM. ^$$$P < 0.001 (vs. Control), ^%P < 0.05 by one-way ANOVA with Tukey post-hoc test; ^¶P < 0.05 (vs. Control) by the Dunnett test; ^#P < 0.05, ^##P < 0.01 (vs. Control) by the Mann-Whitney test.