scholarly journals Role of exendin‐4 in the Gila monster: Further lessons regarding human oral glucagon‐like peptide‐1 therapy?

2020 ◽  
Vol 22 (12) ◽  
pp. 2509-2511
Author(s):  
Galyna V. Graham ◽  
Chris M. McLaughlin ◽  
Peter R. Flatt
Keyword(s):  
Gila Monster ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

scholarly journals Ileal short-chain fatty acids inhibit gastric motility by a humoral pathway

2000 ◽  
Vol 279 (5) ◽  
pp. G925-G930 ◽  
Author(s):  
G. Cuche ◽  
J. C. Cuber ◽  
C. H. Malbert
Keyword(s):  
Gastric Motility ◽  
Short Chain Fatty Acid ◽  
Peptide Yy ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Maximal Amplitude ◽  
Inhibiting Factor ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

The aim of this study was to evaluate the nervous and humoral pathways involved in short-chain fatty acid (SCFA)-induced ileal brake in conscious pigs. The role of extrinsic ileal innervation was evaluated after SCFA infusion in innervated and denervated Babkin's ileal loops, and gastric motility was measured with strain gauges. Peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) concentrations were evaluated in both situations. The possible involvement of absorbed SCFA was tested by using intravenous infusion of acetate. Ileal SCFA infusion in the intact terminal ileum decreased the amplitude of distal and terminal antral contractions (33 ± 1.2 vs. 49 ± 1.2% of the maximal amplitude recorded before infusion) and increased their frequency (1.5 ± 0.11 vs. 1.3 ± 0.10/min). Similar effects were observed during SCFA infusion in ileal innervated and denervated loops (amplitude, 35 ± 1.0 and 34 ± 0.8 vs. 47 ± 1.3 and 43 ± 1.2%; frequency, 1.4 ± 0.07 and 1.6 ± 0.06 vs. 1.1 ± 0.14 and 1.0 ± 0.12/min). Intravenous acetate did not modify the amplitude and frequency of antral contractions. PYY but not GLP-1 concentrations were increased during SCFA infusion in innervated and denervated loops. In conclusion, ileal SCFA inhibit distal gastric motility by a humoral pathway involving the release of an inhibiting factor, which is likely PYY.

Abstract 13483: Pathological Decline in Incretin Hormone Glucagon-like Peptide-1 Causes Cardiac Apoptosis and Dysfunction in Pressure-overloaded Heart Failure Through Cyclic AMP-dependent Mechanisms. -Distinct Role of Protein Kinase a and EPAC

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Morihiko Aoyama ◽  
Yasuko K Bando ◽  
Haruya Kawase ◽  
Akio Monji ◽  
Toko Mitsui ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cyclic Amp ◽  
Left Ventricular ◽  
Ample Evidence ◽  
Incretin Hormone ◽  
Myocardial Apoptosis ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Distinct Role

Introduction: Ample evidence demonstrates cardiovascular protection by incretin hormone glucagon-like peptide-1 (GLP-1) through the cyclic AMP axis. GLP-1 is known for its inotropic effect on heart, however, the role of GLP-1 in heart failure remains uncertain. Hypothesis: To explore the pathophysiological role of GLP-1 in heart failure Methods: Pressure overload-induced heart failure model was generated by transverse aortic constriction in mice (TAC). Results: At 4 week after the operation, TAC exhibited systolic left-ventricular dysfunction, myocardial hypertrophy and augmented apoptosis. Unexpectedly, circulating GLP-1 concentration was markedly decreased in TAC (in pM; 0.86±0.10 for TAC versus 2.13±0.54 for sham) with concomitant reduction of myocardial cyclic AMP concentration (in pmole/mg protein; 33.0±1.4 for TAC versus 42.2±1.5). TAC exhibited pathological changes in signaling molecules of myocardial contractility [SERCA, phospho-phospholamban(Serine16; pPL), β-myosin heavy chain (MYH7)], remodeling (Akt/mTOR/S6K), and cell death markers (procaspase-3/Bcl2 for apoptosis and PINK/PARKIN complex for mitophagy detecting damaged mitochondria). All of these changes observed in TAC heart were reversed selectively by treatment with GLP-1 analog exendin-4 (Ex4; 24nmole/kg/day for 4 weeks) and indirect supplement of GLP-1 by a DPP4 inhibitor alogliptin (ALO; 10mg/kg/day for 4 weeks). In vitro TUNEL assay using cultured cardiomyocytes revealed that Ex-4 reduced myocardial apoptosis in a cAMP/EPAC1-dependent but PKA-independent manner (Figure). Conclusions: Pressure-overloaded heart failure exhibits decline in GLP-1, leading to cAMP/EPAC1-dependent impairment in myocardial apoptosis, and cAMP/PKA/pPL/SERCA-dependent myocardial contractile dysfunction. Our data suggest the distinct role of PKA and EPAC in pathophysiology underlying heart failure.

scholarly journals Zinc-induced activation of GPR39 regulates glucose homeostasis through glucose-dependent insulinotropic polypeptide secretion from enteroendocrine K-cells

2019 ◽  
Vol 400 (8) ◽  
pp. 1023-1033 ◽  
Author(s):  
Brian M. Moran ◽  
Michael G. Miskelly ◽  
Yasser H.A. Abdel-Wahab ◽  
Peter R. Flatt ◽  
Aine M. McKillop
Keyword(s):  
Oral Administration ◽  
Insulin Release ◽  
Glucose Homeostasis ◽  
Knockout Mice ◽  
K Cells ◽  
Integral Role ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Gip Release

Abstract The role of Zn2+-sensing receptor GPR39 on glucose homeostasis and incretin regulation was assessed in enteroendocrine L- and K-cells. Anti-hyperglycaemic, insulinotropic and incretin secreting properties of Zn2+ were explored in normal, diabetic and incretin receptor knockout mice. Compared to intraperitoneal injection, oral administration of Zn2+ (50 μmol/kg body weight) with glucose (18 mmol/kg) in lean mice reduced the glycaemic excursion by 25–34% (p < 0.05–p < 0.001) and enhanced glucose-induced insulin release by 46–48% (p < 0.05–p < 0.01). In diabetic mice, orally administered Zn2+ lowered glucose by 24–31% (p < 0.01) and augmented insulin release by 32% (p < 0.01). In glucagon like peptide-1 (GLP-1) receptor knockout mice, Zn2+ reduced glucose by 15–28% (p < 0.05–p < 0.01) and increased insulin release by 35–43% (p < 0.01). In contrast Zn2+ had no effect on responses of glucose-dependent insulinotropic polypeptide (GIP) receptor knockout mice. Consistent with this, Zn2+ had no effect on circulating total GLP-1 whereas GIP release was stimulated by 26% (p < 0.05) in lean mice. Immunocytochemistry demonstrated GPR39 expression on mouse enteroendocrine L- and K-cells, GLUTag cells and pGIP/Neo STC-1 cells. Zn2+ had a direct effect on GIP secretion from pGIPneo STC-1 cells, increasing GIP secretion by 1.3-fold. GPR39 is expressed on intestinal L- and K-cells, and stimulated GIP secretion plays an integral role in mediating enhanced insulin secretion and glucose tolerance following oral administration of Zn2+. This suggests development of potent and selective GPR39 agonists as a therapeutic approach for diabetes.

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