Plasma ghrelin levels of gastrectomized and vagotomized patients are not affected by glucose administration.
BACKGROUND
Ghrelin is a brain-gut peptide with GH-releasing and appetite-inducing activities, secreted mainly by the stomach. Circulating ghrelin concentrations fall rapidly after nutrient ingestion as well as after oral and intravenous glucose challenge. A number of gut hormones including ghrelin require an intact vagal system, which has been hypothesized to have a major role in initiating the postprandial fall in ghrelin levels.


OBJECTIVE
We aimed to investigate the effect of oral glucose challenge on ghrelin secretion in gastrectomized (GASTRX) and vagotomized patients.


METHODS
Interventional study.


METHODS
Six GASTRX-vagotomized patients and 11 healthy sex- and body mass index (BMI)-matched subjects.


METHODS
An oral glucose tolerance test (OGTT) was performed in all subjects. At baseline, circulating plasma total ghrelin, serum glucose, insulin and GH levels were measured. Serum glucose, insulin, GH and plasma ghrelin levels were determined every 30 min for 2 h.


RESULTS
Plasma ghrelin levels at baseline were reduced by 55% in GASTRX-vagotomized patients compared to the control group (P < 0.01). In control subjects, plasma ghrelin levels decreased significantly during the OGTT whereas in GASTRX-vagotomized patients no reduction was registered (26.4 +/- 2.8% vs. 5.5 +/- 3.4%). The OGTT revealed a significantly greater increase in circulating glucose levels and serum insulin levels while GH response was not different in GASTRX-vagotomized patients compared to control subjects.


CONCLUSIONS
Our data show that circulating ghrelin levels in GASTRX and vagotomized patients were not suppressed after oral glucose administration, unlike control subjects, suggesting that this effect could be due, at least in part, to the lack of contribution of the vagal nervous system to the regulation of ghrelin.
Pekic
S
S
Institute of Endocrinology, Diabetes and Metabolism, University Clinical Centre, Belgrade, Serbia.
Pesko
P
P
Djurovic
M
M
Miljic
D
D
Doknic
M
M
Glodic
J
J
Dieguez
C
C
Casanueva
F F
FF
Popovic
V
V
D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D016022:Case-Control Studies; D005260:Female; D005743:Gastrectomy; D054439:Ghrelin; D005947:Glucose; D005951:Glucose Tolerance Test; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D036361:Peptide Hormones / Q000097:blood*; D013997:Time Factors; D014628:Vagotomy
D054439:Ghrelin; D036361:Peptide Hormones; D013006:Growth Hormone; D005947:Glucose