In both rats and humans there is a distinct circadian rhythm of bile acid synthesis that is independent of feedback regulation. To determine whether the circadian rhythm is directly mediated via hepatic nerves, bile acid synthesis was studied in selectively liver-denervated male Sprague-Dawley rats in a bile fistula model. Complete denervation was confirmed by histofluorescent staining for neural elements in frozen sections of livers. There was no significant difference in mean bile acid synthesis, amplitude of the circadian rhythm, or time of peak synthesis between the denervated rats and nondenervated controls. In one denervated rat studied four times at weekly intervals, there was no shift in acrophase, indicating that the rhythm had not become free running. We conclude that signals arriving via hepatic nerves neither directly cause nor entrain the circadian rhythm of bile acid synthesis in rats.
|Original language||English (US)|
|Journal||American Journal of Physiology - Gastrointestinal and Liver Physiology|
|Issue number||5 24-5|
|State||Published - 1991|
- Bile fistula rat
- Bile formation
- Biological clocks