Circulating ghrelin levels after food intake during different phases of the migrating motor complex in man

Abstract

Background: The timing of the migrating motor complexes (MMC) at food intake may influence gastric emptying and release of regulatory hormones. This report studies the relationships between phases I (motor quiescence) and II (intermediate frequency contractions) of MMC and prandial gut hormone response. Materials and methods: Seven fasting volunteers ingested a meal during phase I or II of MMC verified by manometry, using paracetamol as a marker for gastric emptying. Blood was sampled before, during and 210 min after food intake for analysis of ghrelin, motilin, insulin and paracetamol. Results: The basal level of ghrelin during phase I was 127.5 ± 25.4 pmol L-1 and during phase II was 132.4 ± 24.8 pmol L-1. After food intake during phase I, ghrelin fell to 77.2 ± 10 pmol L-1; in phase II it fell to 82.7 ± 17.8 pmol L-1 within 60 min and returned to baseline levels after 120 min. Baseline levels of motilin were 16 ± 2 pmol L-1 and 18 ± 3 pmol L-1 during phases I and II, respectively. After food, motilin decreased to 8.5 ± 0.7 pmol L-1 and 8.7 ± 1.0 pmol L-1 within 60 min and returned to baseline after 90 min. Insulin levels in phases I and II were 8.1 ± 1.2 mU L-1 and 8.6 ± 0.7 mU L-1, respectively, reaching 138.9 ± 35.6 mU L-1 and 167.4 ± 30.0 mU L-1 at 45 min postprandially. Conclusions: The nutritional status of the gastrointestinal tract at food intake had only a limited impact on plasma ghrelin. After food intake, plasma ghrelin drops, similar to motilin, and resumes preprandial levels within 120 min. © 2006 Blackwell Publishing Ltd.