Effects of meal and incretins in the regulation of splanchnic blood
flow

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Objective

Meal ingestion is followed by a redistribution of blood flow (BF) within the splanchnic region contributing to nutrient absorption, insulin secretion and glucose disposal, but factors regulating this phenomenon in humans are poorly known. The aim of the present study was to evaluate the organ-specific changes in BF during a mixed-meal and incretin infusions.

Design

A non-randomized intervention study of 10 healthy adults to study splanchnic BF regulation was performed.

Methods

Effects of glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) infusions and mixed-meal were tested in 10 healthy, glucose tolerant subjects using PET-MRI multimodal imaging technology. Intestinal and pancreatic BF and blood volume (BV) were measured with ¹⁵O-water and ¹⁵O-carbon monoxide, respectively.

Results

Ingestion of a mixed-meal led to an increase in pancreatic and jejunal BF, whereas duodenal BF was unchanged. Infusion of GIP and GLP-1 reduced BF in the pancreas. However, GIP infusion doubled blood flow in the jejunum with no effect of GLP-1.

Conclusion

Together, our data suggest that meal ingestion leads to increases in pancreatic BF accompanied by a GIP-mediated increase in jejunal but not duodenal blood flow.

Related collections

Most cited references 38

Record: found
Abstract: found
Article: not found

A model-based method for assessing insulin sensitivity from the oral glucose tolerance test.

A Mari, G. Pacini, E. Murphy … (2001)

Available insulin sensitivity (IS) methods based on the oral glucose tolerance test (OGTT) are empirical. We used a glucose-insulin model to derive an OGTT-based IS (oral glucose insulin sensitivity [OGIS]) index, which predicts glucose clearance in a glucose clamp. We validated OGIS against clamp data. OGIS requires glucose and insulin concentrations from a 75-g OGTT at 0, 2, and 3 h (3-h OGTT) or at 0, 1.5, and 2 h (2-h OGTT). The formula includes six constants optimized to match the clamp results. For this purpose, 15 lean nondiabetic subjects (BMI 25 kg/m2), and 38 subjects with type 2 diabetes randomly underwent an OGTT and a 120 mU x min(-1) x m(-2) insulin infusion euglycemic clamp. Glucose clearance (Cl CLAMP), calculated as the ratio of glucose infusion to concentration during the last hour of the clamp, was compared with OGIS. OGIS was also tested on an independent group of 13 subjects with impaired glucose tolerance (IGT). OGIS and Cl CLAMP were correlated in the whole group (R = 0.77, P < 0.0001), in the subgroups (lean: R = 0.59; obese: R = 0.73; type 2 diabetes: R = 0.49; P < 0.02), and in the independent IGT group (R = 0.65, P < 0.02). Reproducibility of OGIS and Cl CLAMP were similar (coefficients of variation: OGIS 7.1%, Cl CLAMP 6.4%). OGIS was as effective as Cl CLAMP in discriminating between groups (for OGIS, lean vs. obese: 440 +/- 16 vs. 362 +/- 11 ml x min(-1) x m(-2), p < 0.001; lean vs. type 2 diabetes: 440 +/- 16 vs. 239 +/- 7, P < 0.0001; obese vs. type 2 diabetes: 362 +/- 11 vs. 239 +/- 7, P < 0.0001; results were similar for Cl CLAMP). The relationships between IS and BMI, fasting plasma insulin, and insulin secretion (calculated from the OGTT insulin concentration) were examined. OGIS yielded results similar to Cl CLAMP and fully consistent with established physiological principles. The performance of the index for the 3-h and 2-h OGTT was similar. OGIS is an index of IS in good agreement with the clamp. Because of its simplicity (only three blood samples required), this method has potential use for clinical investigation including large-scale epidemiological studies.

0 comments Cited 187 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: found

Is Open Access

Glucose-Dependent Insulinotropic Polypeptide

Mikkel Christensen, Louise Vedtofte, Jens Holst … (2011)

OBJECTIVE To evaluate the glucose dependency of glucose-dependent insulinotropic polypeptide (GIP) effects on insulin and glucagon release in 10 healthy male subjects ([means ± SEM] aged 23 ± 1 years, BMI 23 ± 1 kg/m2, and HbA1c 5.5 ± 0.1%). RESEARCH DESIGN AND METHODS Saline or physiological doses of GIP were administered intravenously (randomized and double blinded) during 90 min of insulin-induced hypoglycemia, euglycemia, or hyperglycemia. RESULTS During hypoglycemia, GIP infusion caused greater glucagon responses during the first 30 min compared with saline (76 ± 17 vs. 28 ± 16 pmol/L per 30 min, P < 0.008), with similar peak levels of glucagon reached after 60 min. During euglycemia, GIP infusion elicited larger glucagon responses (62 ± 18 vs. −11 ± 8 pmol/L per 90 min, P < 0.005). During hyperglycemia, comparable suppression of plasma glucagon (−461 ± 81 vs. −371 ± 50 pmol/L per 90 min, P = 0.26) was observed with GIP and saline infusions. In addition, during hyperglycemia, GIP more than doubled the insulin secretion rate (P < 0.0001). CONCLUSIONS In healthy subjects, GIP has no effect on glucagon responses during hyperglycemia while strongly potentiating insulin secretion. In contrast, GIP increases glucagon levels during fasting and hypoglycemic conditions, where it has little or no effect on insulin secretion. Thus, GIP seems to be a physiological bifunctional blood glucose stabilizer with diverging glucose-dependent effects on the two main pancreatic glucoregulatory hormones.

0 comments Cited 136 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Design and performance evaluation of a whole-body Ingenuity TF PET-MRI system.

L. Shao, P Maniawski, D Munguía-Izquierdo … (2011)

The Ingenuity TF PET-MRI is a newly released whole-body hybrid PET-MR imaging system with a Philips time-of-flight GEMINI TF PET and Achieva 3T X-series MRI system. Compared to PET-CT, modifications to the positron emission tomography (PET) gantry were made to avoid mutual system interference and deliver uncompromising performance which is equivalent to the standalone systems. The PET gantry was redesigned to introduce magnetic shielding for the photomultiplier tubes (PMTs). Stringent electromagnetic noise requirements of the MR system necessitated the removal of PET gantry electronics to be housed in the PET-MR equipment room. We report the standard NEMA measurements for the PET scanner. PET imaging and performance measurements were done at Geneva University Hospital as described in the NEMA Standards NU 2-2007 manual. The scatter fraction (SF) and noise equivalent count rate (NECR) measurements with the NEMA cylinder (20 cm diameter) were repeated for two larger cylinders (27 cm and 35 cm diameter), which better represent average and heavy patients. A NEMA/IEC torso phantom was used for overall assessment of image quality. The transverse and axial resolution near the center was 4.7 mm. Timing and energy resolution of the PET-MR system were measured to be 525 ps and 12%, respectively. The results were comparable to PET-CT systems demonstrating that the effect of design modifications required on the PET system to remove the harmful effect of the magnetic field on the PMTs was negligible. The absolute sensitivity of this scanner was 7.0 cps kBq(-1), whereas SF was 26%. NECR measurements performed with cylinders having three different diameters, and image quality measurements performed with IEC phantom yielded excellent results. The Ingenuity TF PET-MRI represents the first commercial whole-body hybrid PET-MRI system. The performance of the PET subsystem was comparable to the GEMINI TF PET-CT system using phantom and patient studies. It is conceived that advantages of hybrid PET-MRI will become more evident in the near future.

0 comments Cited 70 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): Endocr Connect

Journal ID (iso-abbrev): Endocr Connect

Journal ID (hwp): EC

Title: Endocrine Connections

Publisher: Bioscientifica Ltd (Bristol )

ISSN (Electronic): 2049-3614

Publication date Collection: February 2017

Publication date (Electronic): 03 March 2017

Volume: 6

Issue: 3

Pages: 179-187

Affiliations

[1 ]Department of Gastroenterology Turunmaa Hospital, Turku, Finland

[2 ]Turku PET Centre University of Turku, Turku, Finland

[3 ]Division of Digestive Surgery and Urology Turku University Hospital, Turku, Finland

[4 ]Institute of Biostatistics University of Turku, Turku, Finland

[5 ]Department of Radiology University of Turku and Turku University Hospital, Turku, Finland

[6 ]Institute of Neuroscience National Research Council, Padua, Italy

[7 ]Department of Clinical Sciences Lund University Diabetes Centre, Malmö, Sweden

[8 ]Department of Endocrinology Turku University Hospital, Turku, Finland

Author notes

Correspondence should be addressed to P Nuutila; Email: pirjo.nuutila@ 123456utu.fi

[*]

(J Koffert and H Honka contributed equally to this work)

Article

Publisher ID: EC170015

DOI: 10.1530/EC-17-0015

PMC ID: 5428912

PubMed ID: 28258126

SO-VID: f43d660a-0ae6-40ad-8dc0-2adf830075b1

License:

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License..

The flagship journal of the Society for Endocrinology. Learn more

Effects of meal and incretins in the regulation of splanchnic blood flow

Read this article at

Abstract

Objective

Design

Methods

Results

Conclusion

Related collections

Bioscientifica Open Endocrinology

Most cited references 38

A model-based method for assessing insulin sensitivity from the oral glucose tolerance test.

Glucose-Dependent Insulinotropic Polypeptide

Design and performance evaluation of a whole-body Ingenuity TF PET-MRI system.

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 706

Cited by 9

Most referenced authors 650