Effect of GLP-1 on gastric volume, emptying, maximum volume ingested, and postprandial symptoms in humans (original) (raw)
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Effect of GLP-1 on gastric volume, emptying, maximum volume ingested, and postprandial symptoms in humans. Am J Physiol Gastrointest Liver Physiol 282: G424-G431, 2002.-Glucagon-like peptide-1 (GLP-1) relaxes the stomach during fasting but decreases hunger and food consumption and retards gastric emptying. The interrelationships between volume, emptying, and postprandial symptoms in response to GLP-1 are unclear. We performed, in healthy human volunteers, a placebo-controlled study of the effects of intravenous GLP-1 on gastric volume using 99m Tc-single photon emission computed tomography imaging, gastric emptying of a nutrient liquid meal (Ensure) using scintigraphy, maximum tolerated volume (MTV) of Ensure, and postprandial symptoms 30 min after MTV. The role of vagal cholinergic function in the effects of GLP-1 was assessed by human pancreatic polypeptide (HPP) response to the Ensure meal. GLP-1 increased fasting and postprandial gastric volumes and retarded gastric emptying; MTV and postprandial symptoms were not different compared with controls. Effects on postprandial gastric function were associated with reduced postprandial HPP levels. GLP-1 does not induce postprandial symptoms despite significant inhibition of gastric emptying and vagal function; this may be partly explained by the increase in postprandial gastric volume. accommodation; single photon emission computed tomography; vagus; satiation; diabetes Address for reprint requests and other correspondence: M. Camilleri, Mayo Clinic, Charlton 7-154, 200 First St. S.W., Rochester, MN 55905.
Effects of glucagon-like peptide-1 (GLP-1) on gastric accommodation, emptying and satiety in humans
Gastroenterology, 2001
Effect of GLP-1 on gastric volume, emptying, maximum volume ingested, and postprandial symptoms in humans. Am J Physiol Gastrointest Liver Physiol 282: G424-G431, 2002.-Glucagon-like peptide-1 (GLP-1) relaxes the stomach during fasting but decreases hunger and food consumption and retards gastric emptying. The interrelationships between volume, emptying, and postprandial symptoms in response to GLP-1 are unclear. We performed, in healthy human volunteers, a placebo-controlled study of the effects of intravenous GLP-1 on gastric volume using 99m Tc-single photon emission computed tomography imaging, gastric emptying of a nutrient liquid meal (Ensure) using scintigraphy, maximum tolerated volume (MTV) of Ensure, and postprandial symptoms 30 min after MTV. The role of vagal cholinergic function in the effects of GLP-1 was assessed by human pancreatic polypeptide (HPP) response to the Ensure meal. GLP-1 increased fasting and postprandial gastric volumes and retarded gastric emptying; MTV and postprandial symptoms were not different compared with controls. Effects on postprandial gastric function were associated with reduced postprandial HPP levels. GLP-1 does not induce postprandial symptoms despite significant inhibition of gastric emptying and vagal function; this may be partly explained by the increase in postprandial gastric volume. accommodation; single photon emission computed tomography; vagus; satiation; diabetes Address for reprint requests and other correspondence: M. Camilleri, Mayo Clinic, Charlton 7-154, 200 First St. S.W., Rochester, MN 55905.
Diabetes, 2011
OBJECTIVE Glucagon-like peptide (GLP)-1 lowers postprandial glycemia primarily through inhibition of gastric emptying. We addressed whether the GLP-1–induced deceleration of gastric emptying is subject to rapid tachyphylaxis and if so, how this would alter postprandial glucose control. RESEARCH DESIGN AND METHODS Nine healthy volunteers (25 ± 4 years old, BMI: 24.6 ± 4.7 kg/m2) were examined with intravenous infusion of GLP-1 (0.8 pmol · kg−1 . min−1) or placebo over 8.5 h. Two liquid mixed meals were administered at a 4-h interval. Gastric emptying was determined, and blood samples were drawn frequently. RESULTS GLP-1 decelerated gastric emptying significantly more after the first meal compared with the second meal (P = 0.01). This was associated with reductions in pancreatic polypeptide levels (marker of vagal activation) after the first but not the second meal (P < 0.05). With GLP-1, glucose concentrations declined after the first meal but increased after the second meal (P &l...
GLP-1 slows solid gastric emptying and inhibits insulin, glucagon, and PYY release in humans
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 1999
The aim of the present study was to assess the effect of glucagon-like peptide-1 (GLP-1) on solid gastric emptying and the subsequent release of pancreatic and intestinal hormones. In eight men [age 33.6 ± 2.5 yr, body mass index 24.1 ± 0.9 (means ± SE)], scintigraphic solid gastric emptying during infusion of GLP-1 (0.75 pmol ⋅ kg−1 ⋅ min−1) or saline was studied for 180 min. Concomitantly, plasma concentrations of C- and N-terminal GLP-1, glucose, insulin, C-peptide, glucagon, and peptide YY (PYY) were assessed. Infusion of GLP-1 resulted in a profound inhibition of both the lag phase (GLP-1: 91.5, range 73.3–103.6 min vs. saline: 19.5, range 10.2–43.4 min) and emptying rate (GLP-1: 0.34, range 0.06–0.56 %/min vs. saline: 0.84, range 0.54–1.33 %/min; P< 0.01 for both) of solid gastric emptying. Concentrations of both intact and total GLP-1 were elevated to supraphysiological levels. Plasma glucose and glucagon concentrations were below baseline during infusion of GLP-1 in contr...
Interactions between gastric emptying and satiety, with special reference to glucagon-like peptide-1
Physiology & Behavior, 2001
The slowing of gastric emptying is an important mechanism for the satiating effect of gut peptide signaling. After food intake, cholecystokinin (CCK), as well as glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2), are released from the gastrointestinal tract to mediate satiety. In humans, CCK and the GLP-1 have been found to cause satiety in both normal and obese subjects. This satiating effect may be caused by the peptides circulating as hormones with direct effects in the central nervous system, or indirect effects through signals mediated either via the vagus nerve or by activation of vagal afferent fibers due to slow gastric emptying. These peptides also cause gastric relaxation, considered an additional component in the satiating effect of the peptides. To conclude, after food intake, gut peptides may act in concert as neurohormonal satiety signals acting directly in the brain or indirectly via the vagus nerve, as well as through gastric sensory mechanisms to limit food intake.
Glucagon-like peptide-1 inhibits gastric emptying via vagal afferent-mediated central mechanisms
The American journal of physiology, 1997
Exogenous administration of glucagon-like peptide-1-(7-36) amide (GLP-1), an insulinotropic hormone, inhibits gastric emptying and acid secretion in humans. The role of GLP-1 as a regulator of gastric function is elusive. In gastric fistula rats, vagal afferent denervation and peripheral administration of the GLP-1 receptor antagonist exendin-(9-39) amide enhanced emptying of a glucose meal, whereas intracerebroventricular exendin was ineffective. The rate of saline emptying was attenuated by peripheral as well as by central administration of GLP-1, and pretreatment with exendin by the respective routes reversed the inhibition by GLP-1. Vagal afferent denervation abolished the central and peripheral action of GLP-1 on gastric emptying. Neither peripheral cholinergic nor adrenergic blockade altered the delay of methyl cellulose meal emptying by intracisternal GLP-1 injection. Acid secretion in conscious pylorus-ligated rats was inhibited by intracisternal GLP-1 administration, wherea...
Peripheral administration of GLP-2 to humans has no effect on gastric emptying or satiety
Regulatory Peptides, 2003
Glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) are secreted in parallel to the circulation after a meal. Intravenous (IV) GLP-1 has an inhibitory effect on gastric emptying, hunger and food intake in man. In rodents, central administration of GLP-2 increases satiety similar to GLP-1. The aim of the present study was to assess the effect of IV administered GLP-2 on gastric emptying and feelings of hunger in human volunteers. In eight (five men) healthy subjects (age 31.1 F 2.9 years and BMI 24.1 F 1.0 kg m À 2 ), scintigraphic solid gastric emptying, hunger ratings (VAS) and plasma concentrations of GLP-2 were studied during infusion of saline or GLP-2 (0.75 and 2.25 pmol kg À 1 min À 1 ) for a total of 180 min. Concentrations of GLP-2 were elevated to a maximum of 50 and 110 pmol l À 1 for 0.75 and 2.25 pmol kg À 1 min À 1 infusion of GLP-2, respectively. There was no effect of GLP-2 on either the lag phase (29.5 F 4.4, 26.0 F 5.2 and 21.2 F 3.6 min for saline, GLP-2 0.75 or 2.25 pmol kg À 1 min À 1 , respectively) or the half emptying time (84.5 F 6.1, 89.5 F 17.8 and 85.0 F 7.0 min for saline, GLP-2 0.75 or 2.25 pmol kg À 1 min À 1 , respectively). The change in hunger rating after the meal to 180 min was also unaffected by infusion of GLP-2. GLP-2 does not seem to mediate the ileal brake mechanism. D
The Journal of Clinical Endocrinology & Metabolism, 2011
Objective: Synthetic glucagon-like peptide-1 (7-36)amide (GLP-1) lowers postprandial (pp) glycemia by stimulating insulin and inhibiting glucagon release and delaying gastric emptying (GE). However, the biological effects of the endogenous peptide and their relative contributions to pp glycemia remain to be defined in detail. Using the specific GLP-1 receptor antagonist exendin(9-39)amide [Ex(9-39)], we studied the exact impact of GLP-1 after an oral meal in humans. Research Design and Methods: After a 50-min basal period, 12 healthy subjects ingested a 412-kcal mixed semisolid meal containing 30 g oatmeal, labeled with 99mTc-Sn-colloid. GE was measured by high-resolution scintigraphy until 210 min after meal ingestion. In random order, saline or Ex(9-39) at 900 pmol/kg⅐min was infused iv. Additionally, in six subjects gastric motility was measured by antroduodenal manometry and a gastric barostat in parallel. Results: Ex(9-39) increased pp blood glucose excursions during the first 60 min after the meal (43.9 Ϯ 5.4 vs. 35.9 Ϯ 3.6 mg/dl, P ϭ 0.008; pp peak glucose 154.0 Ϯ 5.5 vs.141.0 Ϯ 4.7 mg/dl, P ϭ 0.009). Insulin increased slightly with Ex(9-39), whereas the insulin to glucose ratio was unchanged. pp glucagon was significantly increased with Ex(9-39) (7.5 Ϯ 2.4 vs. 3.2 Ϯ 2.1 pg/ml, P ϭ 0.024). GE and accordingly gastric motility did not change with Ex(9-39). Multiple linear regression analysis revealed only changes of pp glucagon to be significantly associated with increased pp glycemia under Ex(9-39) (R ϭ 0.678, P ϭ 0.015). Conclusions: Released after an oral meal, GLP-1 lowers pp glycemia. In this study, the inhibition of glucagon release was a major determinant of the acute GLP-1 action in healthy subjects. In contrast, gastric emptying was not changed by GLP-1 receptor antagonism.
American Journal of Physiology-Endocrinology and Metabolism, 2006
Glucagon-like peptide 1 (GLP-1) lowers glycemia by modulating gastric emptying and endocrine pancreatic secretion. Rapidly after its secretion, GLP-1-(7–36) amide is degraded to the metabolite GLP-1-(9–36) amide. The effects of GLP-1-(9–36) amide in humans are less well characterized. Fourteen healthy volunteers were studied with intravenous infusion of GLP-1-(7–36) amide, GLP-1-(9–36) amide, or placebo over 390 min. After 30 min, a solid test meal was served, and gastric emptying was assessed. Blood was drawn for GLP-1 (total and intact), glucose, insulin, C-peptide, and glucagon measurements. Administration of GLP-1-(7–36) amide and GLP-1-(9–36) amide significantly raised total GLP-1 plasma levels. Plasma concentrations of intact GLP-1 increased to 21 ± 5 pmol/l during the infusion of GLP-1-(7–36) amide but remained unchanged during GLP-1-(9–36) amide infusion [5 ± 3 pmol/l; P < 0.001 vs. GLP-1-(7–36) amide administration]. GLP-1-(7–36) amide reduced fasting and postprandial gl...