Chronobiology international
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The rhythmic recurrence of biological processes is driven by the functioning of cellular circadian clocks, operated by a set of genes and proteins that generate self-sustaining transcriptional-translational feedback loops with a free-running period of about 24 h. In the gastrointestinal apparatus, the functioning of the biological clocks shows distinct patterns in the different organs. The aim of this study was to evaluate the time-related variation of clock gene expression in mouse liver and stomach, two components of the digestive system sharing vascular and autonomic supply, but performing completely different functions. ⋯ The acrophase of the fractional variations of Bmal1, Per2, Per3, Rev-erbα, Rev-erbβ, and Dbp expression was delayed in the stomach, and the average delay expressed as mean ± SD was 19.10 ± 9.39 degrees (76.40 ± 37.59 minutes). A significantly greater fractional variation was found in the liver for Clock at 06:00 h (p = .034), Per1 at 02:00 h (p = .037), and Per3 at 02:00 h (p = .029), whereas the fractional variation was greater in the stomach for Clock at 10:00 h (p = .016), and for Npas2 at 02:00 h (p = .029) and at 06:00 h (p = .044). In conclusion, liver and stomach show different phasing and dynamics of clock gene expression, which are probably related to prevailing control by different driving cues, and allow them to keep going the various metabolic pathways and diverse functional processes that they manage.