Ghrelin stimulates gastric emptying and hunger in normal-weight humans.
BACKGROUND
Ghrelin is produced primarily by enteroendocrine cells in the gastric mucosa and increases gastric emptying in patients with gastroparesis.


OBJECTIVE
The objective of the study was to evaluate the effect of ghrelin on gastric emptying, appetite, and postprandial hormone secretion in normal volunteers.


METHODS
This was a randomized, double-blind, crossover study.


METHODS
Subjects included normal human volunteers and patients with GH deficiency.


METHODS
Intervention included saline or ghrelin (10 pmol/kg.min) infusion for 180 min after intake of a radioactively labeled omelette (310 kcal) or GH substitution in GH-deficient patients.


METHODS
Measures consisted of gastric empty-ing parameters and postprandial plasma levels of ghrelin, cholecystokinin, glucagon-like peptide-1, peptide YY, and motilin.


RESULTS
The emptying rate was significantly faster for ghrelin (1.26 +/- 0.1% per minute), compared with saline (0.83% per minute) (P < 0.001). The lag phase (16.2 +/- 2.2 and 26.5 +/- 3.8 min) and half-emptying time (49.4 +/- 3.9 and 75.6 +/- 4.9 min) of solid gastric emptying were shorter during ghrelin infusion, compared with infusion of saline (P < 0.001). The postprandial peak in plasma concentration for cholecystokinin and glucagon-like peptide-1 occurred earlier and was higher during ghrelin infusion. There was no significant effect of ghrelin on plasma motilin or peptide YY. There was no difference in gastric emptying before and after GH substitution.


CONCLUSIONS
Our results demonstrate that ghrelin increases the gastric emptying rate in normal humans. The effect does not seem to be mediated via GH or motilin but may be mediated by the vagal nerve or directly on ghrelin receptors in the stomach. Ghrelin receptor agonists may have a role as prokinetic agents.
Levin
F
F
Department of Surgery, Danderyd Hospital, SE-182 88 Stockholm, Sweden. fredrik.levin@ds.se
Edholm
T
T
Schmidt
P T
PT
Grybäck
P
P
Jacobsson
H
H
Degerblad
M
M
Höybye
C
C
Holst
J J
JJ
Rehfeld
J F
JF
Hellström
P M
PM
Näslund
E
E
D000328:Adult; D002766:Cholecystokinin / Q000097:blood; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects* / Q000502:physiology; D005753:Gastric Mucosa / Q000378:metabolism; D054439:Ghrelin; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D019382:Human Growth Hormone / Q000097:blood / Q000172:deficiency / Q000627:therapeutic use; D006801:Humans; D006815:Hunger / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009037:Motilin / Q000097:blood; D036361:Peptide Hormones / Q000097:blood / Q000235:genetics / Q000494:pharmacology*; D019894:Peptide YY / Q000097:blood; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D054440:Receptors, Ghrelin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000187:drug effects
D054439:Ghrelin; D036361:Peptide Hormones; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin; D019894:Peptide YY; D019382:Human Growth Hormone; D009037:Motilin; D052216:Glucagon-Like Peptide 1; D002766:Cholecystokinin