Background: Ghrelin and Peptide YY3-36 are gastrointestinal hormones related energy homeostasis. We investigated the changes in post-meal plasma ghrelin and PYY3-36 levels in people after meal, simultaneously.
Methods: Nine healthy volunteers adhered to strict meal times starting two weeks before the study. Blood was drawn hourly for 4 hours. Plasma ghrelin, PYY3-36, leptin, and insulin levels were measured by radioimmunoassay (RIA).
Results: The mean plasma ghrelin level in subjects consuming the meal was 588.0 ± 204.4 pg/mL just before breakfast and 394.22 ± 145.25 pg/mL 1 h after meal, with the mean plasma PYY3-36 levels of 29.9 ± 13.7 pmol/L and 44.2 ± 12.1 pmol/L, respectively. The mean plasma leptin level in subjects consuming the meal was 7.4 ± 2.7 ng/mL before the meal and 7.1 ± 2.9 ng/mL 1 h after meal, with insulin levels of 129.8 ± 50.0 pmol/L and 658.8 ± 332.3 pmol/L, respectively. Plasma ghrelin levels were lowest 1 h after the meal, although PYY3-36 levels were highest 1 h after the meal.
Conclusion: While plasma ghrelin levels were lowest 1 h, PYY3-36 levels were highest 1 h after the meal. These findings suggest that Plasma ghrelin and peptide YY3-36 levels change in opposite ways at the same speed.

Keywords: Peptide YY, Ghrelin, Leptin, Insulin, Meal, Stomach, Colon