Related Experiment Video
Updated: Feb 16, 2026

Meal Duration as a Measure of Orofacial Nociceptive Responses in Rodents
Published on: January 10, 2014
Meal-related oscillations in the serum serotonin levels in healthy young men
Obin Kwon1,2, Ji Hee Yu3, Eunheui Jeong4
1Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Korea.
Context:
Serotonin acts as a neurotransmitter in the central and enteric nervous systems, modulating psychological, metabolic and gastrointestinal functions. Serotonin is also found in the serum or plasma, indicating its potential role as a hormone.
Objective:
We aimed to assess the 24-hour diurnal profile of serum serotonin in relation to meal ingestion in healthy adult men.
Methods:
Ten healthy (5 lean and 5 obese) male subjects were enrolled in this study. Blood samples were drawn every 30-60 minutes throughout a 24-hour period to determine the serotonin levels. Three meals were provided on a fixed schedule. To confirm the effect of meal intake on serum serotonin levels, 4 subjects underwent fasting until 1500 h and were then provided a meal without notice.
Results:
Serum serotonin levels had distinct diurnal variations, with the highest levels early in the morning and the lowest levels in the midafternoon and during sleep. Notably, these diurnal oscillations were markedly reduced in obese subjects. Fluctuations in serum serotonin levels were associated with meal intake, and the levels peaked 30 minutes before meals and exhibited a trough during the postprandial period. Fasting blunted the meal-related oscillations in serum serotonin levels. Moreover, unexpected meal intake did not lead to a premeal increase in serum serotonin levels.
Conclusions:
Serum serotonin levels displayed meal-related diurnal oscillations, which were disrupted by fasting and obesity. These findings suggest the possibility that circulating serotonin modulates metabolic function in humans.
More Related Videos
08:43Isolation of Endothelial Progenitor Cells from Healthy Volunteers and Their Migratory Potential Influenced by Serum Samples After Cardiac Surgery
Published on: February 14, 2017
09:42Feeding and Quantifying Animal-Derived Blood and Artificial Meals in Aedes aegypti Mosquitoes
Published on: October 22, 2020
Related Concept Videos
Oscillations In An LC Circuit
Forced Oscillations
Damped Oscillations
Although friction and other non-conservative...
Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists
Limits with Oscillating Discontinuities
Oscillations about an Equilibrium Position