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Richter MM, Kemp IM, Heebøll S, Winther-Sørensen M, Kjeldsen SAS, Jensen NJ, Nybing JD, Linden FH, Høgh-Schmidt E, Boesen MP, Madsbad S, Schiødt FV, Nørgaard K, Schmidt S, Gluud LL, Haugaard SB, Holst JJ, Nielsen S, Rungby J, Wewer Albrechtsen NJ. Glucagon augments the secretion of FGF21 and GDF15 in MASLD by indirect mechanisms. Metabolism 2024:155915. [PMID: 38631460 DOI: 10.1016/j.metabol.2024.155915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/19/2024]
Abstract
INTRODUCTION Glucagon receptor agonism is currently explored for the treatment of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). The metabolic effects of glucagon receptor agonism may in part be mediated by increases in circulating levels of Fibroblast Growth Factor 21 (FGF21) and Growth Differentiation Factor 15 (GDF15). The effect of glucagon agonism on FGF21 and GDF15 levels remains uncertain, especially in the context of elevated insulin levels commonly observed in metabolic diseases. METHODS We investigated the effect of a single bolus of glucagon and a continuous infusion of glucagon on plasma concentrations of FGF21 and GDF15 in conditions of endogenous low or high insulin levels. The studies included individuals with overweight with and without MASLD, healthy controls (CON) and individuals with type 1 diabetes (T1D). The direct effect of glucagon on FGF21 and GDF15 was evaluated using our in-house developed isolated perfused mouse liver model. RESULTS FGF21 and GDF15 correlated with plasma levels of insulin, but not glucagon, and their secretion were highly increased in MASLD compared with CON and T1D. Furthermore, FGF21 levels in individuals with overweight with or without MASLD did not increase after glucagon stimulation when insulin levels were kept constant. FGF21 and GDF15 levels were unaffected by direct stimulation with glucagon in the isolated perfused mouse liver. CONCLUSION The glucagon-induced secretion of FGF21 and GDF15 are augmented in MASLD and may depend on insulin. Thus, glucagon receptor agonism may augment its metabolic benefits in patients with MASLD through enhanced secretion of FGF21 and GDF15.
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Affiliation(s)
- Michael M Richter
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Ida M Kemp
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Sara Heebøll
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus 8200, Denmark; Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus 8200, Denmark
| | - Marie Winther-Sørensen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Sasha A S Kjeldsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Nicole J Jensen
- Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | - Janus D Nybing
- Department of Radiology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | - Frederik H Linden
- Department of Radiology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | - Erik Høgh-Schmidt
- Department of Radiology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | - Mikael P Boesen
- Department of Radiology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital - Hvidovre, Hvidovre 2650, Denmark
| | - Frank Vinholt Schiødt
- Department of Clinical Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | | | - Signe Schmidt
- Steno Diabetes Center Copenhagen, Herlev 2730, Denmark
| | - Lise Lotte Gluud
- Gastro Unit, Copenhagen University Hospital - Hvidovre, Hvidovre 2650, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Steen B Haugaard
- Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Søren Nielsen
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus 8200, Denmark; Department of Clinical Medicine, Aarhus University Hospital, Aarhus 8200, Denmark
| | - Jørgen Rungby
- Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark; Department of Clinical Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark; Steno Diabetes Center Copenhagen, Herlev 2730, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen 2400, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.
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Stangerup I, Kjeldsen SAS, Richter MM, Jensen NJ, Rungby J, Haugaard SB, Georg B, Hannibal J, Møllgård K, Wewer Albrechtsen NJ, Bjørnbak Holst C. Glucagon does not directly stimulate pituitary secretion of ACTH, GH or copeptin. Peptides 2024; 176:171213. [PMID: 38604379 DOI: 10.1016/j.peptides.2024.171213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/20/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
Glucagon is best known for its contribution to glucose regulation through activation of the glucagon receptor (GCGR), primarily located in the liver. However, glucagon's impact on other organs may also contribute to its potent effects in health and disease. Given that glucagon-based medicine is entering the arena of anti-obesity drugs, elucidating extrahepatic actions of glucagon are of increased importance. It has been reported that glucagon may stimulate secretion of arginine-vasopressin (AVP)/copeptin, growth hormone (GH) and adrenocorticotrophic hormone (ACTH) from the pituitary gland. Nevertheless, the mechanisms and whether GCGR is present in human pituitary are unknown. In this study we found that intravenous administration of 0.2 mg glucagon to 14 healthy subjects was not associated with increases in plasma concentrations of copeptin, GH, ACTH or cortisol over a 120-min period. GCGR immunoreactivity was present in the anterior pituitary but not in cells containing GH or ACTH. Collectively, glucagon may not directly stimulate secretion of GH, ACTH or AVP/copeptin in humans but may instead be involved in yet unidentified pituitary functions.
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Affiliation(s)
- Ida Stangerup
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Clinical Biochemistry, Copenhagen University Hospital - Nordsjælland, Hillerød, Denmark.
| | - Sasha A S Kjeldsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael M Richter
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicole J Jensen
- Steno Diabetes Center Copenhagen, Herlev, Denmark; Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Jørgen Rungby
- Steno Diabetes Center Copenhagen, Herlev, Denmark; Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steen Bendix Haugaard
- Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Georg
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Jens Hannibal
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kjeld Møllgård
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Bjørnbak Holst
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Zilstorff DB, Richter MM, Hannibal J, Jørgensen HL, Sennels HP, Wewer Albrechtsen NJ. Secretion of glucagon, GLP-1 and GIP may be affected by circadian rhythm in healthy males. BMC Endocr Disord 2024; 24:38. [PMID: 38481208 PMCID: PMC10938734 DOI: 10.1186/s12902-024-01566-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/04/2024] [Indexed: 03/17/2024] Open
Abstract
BACKGROUND Glucagon is secreted from pancreatic alpha cells in response to low blood glucose and increases hepatic glucose production. Furthermore, glucagon enhances hepatic protein and lipid metabolism during a mixed meal. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted from gut endocrine cells during meals and control glucose homeostasis by potentiating insulin secretion and inhibiting food intake. Both glucose homeostasis and food intake have been reported to be affected by circadian rhythms and vice versa. In this study, we investigated whether the secretion of glucagon, GLP-1 and GIP was affected by circadian rhythms. METHODS A total of 24 healthy men with regular sleep schedules were examined for 24 h at the hospital ward with 15 h of wakefulness and 9 h of sleep. Food intake was standardized, and blood samples were obtained every third hour. Plasma concentrations of glucagon, GLP-1 and GIP were measured, and data were analyzed by rhythmometric statistical methods. Available data on plasma glucose and plasma C-peptide were also included. RESULTS Plasma concentrations of glucagon, GLP-1, GIP, C-peptide and glucose fluctuated with a diurnal 24-h rhythm, with the highest levels during the day and the lowest levels during the night: glucagon (p < 0.0001, peak time 18:26 h), GLP-1 (p < 0.0001, peak time 17:28 h), GIP (p < 0.0001, peak time 18:01 h), C-peptide (p < 0.0001, peak time 17.59 h), and glucose (p < 0.0001, peak time 23:26 h). As expected, we found significant correlations between plasma concentrations of C-peptide and GLP-1 and GIP but did not find correlations between glucose concentrations and concentrations of glucagon, GLP-1 and GIP. CONCLUSIONS Our results demonstrate that under meal conditions that are similar to that of many free-living individuals, plasma concentrations of glucagon, GLP-1 and GIP were observed to be higher during daytime and evening than overnight. These findings underpin disturbed circadian rhythm as a potential risk factor for diabetes and obesity. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT06166368. Registered 12 December 2023.
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Affiliation(s)
- Dorte B Zilstorff
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg Hospital, Copenhagen, Denmark
| | - Michael M Richter
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg Hospital, Copenhagen, Denmark
- NNF Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Hannibal
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg Hospital, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik L Jørgensen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Hvidovre, Hvidovre, Denmark
| | - Henriette P Sennels
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg Hospital, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg Hospital, Copenhagen, Denmark.
- NNF Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Richter MM, Thomsen MN, Skytte MJ, Kjeldsen SAS, Samkani A, Frystyk J, Magkos F, Holst JJ, Madsbad S, Krarup T, Haugaard SB, Wewer Albrechtsen NJ. Effect of a 6-Week Carbohydrate-Reduced High-Protein Diet on Levels of FGF21 and GDF15 in People With Type 2 Diabetes. J Endocr Soc 2024; 8:bvae008. [PMID: 38379856 PMCID: PMC10875725 DOI: 10.1210/jendso/bvae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Indexed: 02/22/2024] Open
Abstract
Context Fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15) are increased in type 2 diabetes and are potential regulators of metabolism. The effect of changes in caloric intake and macronutrient composition on their circulating levels in patients with type 2 diabetes are unknown. Objective To explore the effects of a carbohydrate-reduced high-protein diet with and without a clinically significant weight loss on circulating levels of FGF21 and GDF15 in patients with type 2 diabetes. Methods We measured circulating FGF21 and GDF15 in patients with type 2 diabetes who completed 2 previously published diet interventions. Study 1 randomized 28 subjects to an isocaloric diet in a 6 + 6-week crossover trial consisting of, in random order, a carbohydrate-reduced high-protein (CRHP) or a conventional diabetes (CD) diet. Study 2 randomized 72 subjects to a 6-week hypocaloric diet aiming at a ∼6% weight loss induced by either a CRHP or a CD diet. Fasting plasma FGF21 and GDF15 were measured before and after the interventions in a subset of samples (n = 24 in study 1, n = 66 in study 2). Results Plasma levels of FGF21 were reduced by 54% in the isocaloric study (P < .05) and 18% in the hypocaloric study (P < .05) in CRHP-treated individuals only. Circulating GDF15 levels increased by 18% (P < .05) following weight loss in combination with a CRHP diet but only in those treated with metformin. Conclusion The CRHP diet significantly reduced FGF21 in people with type 2 diabetes independent of weight loss, supporting the role of FGF21 as a "nutrient sensor." Combining metformin treatment with carbohydrate restriction and weight loss may provide additional metabolic improvements due to the rise in circulating GDF15.
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Affiliation(s)
- Michael M Richter
- Department of Clinical Biochemistry, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Mads N Thomsen
- Department of Endocrinology, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
| | - Mads J Skytte
- Department of Endocrinology, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Department of Forensic Medicine, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Sasha A S Kjeldsen
- Department of Clinical Biochemistry, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Amirsalar Samkani
- Department of Endocrinology, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
| | - Jan Frystyk
- Department of Endocrinology, Odense University Hospital, Odense, 5000, Denmark
| | - Faidon Magkos
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital—Hvidovre, Hvidovre, 2650, Denmark
| | - Thure Krarup
- Department of Endocrinology, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Steen B Haugaard
- Department of Endocrinology, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Copenhagen University Hospital—Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
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Rasmussen C, Richter MM, Jensen NJ, Heinz N, Hartmann B, Holst JJ, Kjeldsen SAS, Wewer Albrechtsen NJ. Preanalytical impact on the accuracy of measurements of glucagon, GLP-1 and GIP in clinical trials. Scand J Clin Lab Invest 2023; 83:591-598. [PMID: 38127365 DOI: 10.1080/00365513.2023.2294470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND Plasma concentrations of glucagon, GLP-1 and GIP are reported in numerous clinical trials as outcome measures but preanalytical guidelines are lacking. We addressed the impact of commonly used blood containers in metabolic research on measurements of glucagon, GLP-1 and GIP in humans. METHODS Seventeen overweight individuals were subjected to an overnight fast followed by an intravenous infusion of amino acids to stimulate hormonal secretion. Blood was sampled into five containers: EDTA-coated tubes supplemented with DMSO (control), a neprilysin inhibitor, aprotinin (a kallikrein inhibitor) or a DPP-4 inhibitor, and P800 tubes. Plasma was kept on ice before and after centrifugation and stored at -80 Celsius until batch analysis using validated sandwich ELISAs or radioimmunoassays (RIA). RESULTS Measures of fasting plasma glucagon did not depend on sampling containers, whether measured by ELISA or RIA. Amino acid-induced hyperglucagonemia was numerically higher when blood was collected into P800 tubes or tubes with aprotinin. The use of p800 tubes resulted in higher concentrations of GLP-1 by RIA compared to control tubes but not for measurements with sandwich ELISA. Plasma concentrations of GIP measured by ELISA were higher in control tubes and negatively affected by P800 and the addition of aprotinin. CONCLUSIONS The choice of blood containers impacts on measurements of plasma concentrations of glucagon, GLP-1 and GIP, and based on this study, we recommend using EDTA-coated tubes without protease inhibitors or P800 tubes for measurements of glucagon, GLP-1 and GIP in clinical trials.
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Affiliation(s)
- Christine Rasmussen
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael M Richter
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicole J Jensen
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Niklas Heinz
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordic Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sasha A S Kjeldsen
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Kjeldsen SA, Gluud LL, Werge MP, Pedersen JS, Bendtsen F, Alexiadou K, Tan T, Torekov SS, Iepsen EW, Jensen NJ, Richter MM, Goetze JP, Rungby J, Hartmann B, Holst JJ, Holst B, Holt J, Gustafsson F, Madsbad S, Svane MS, Bojsen-Møller KN, Wewer Albrechtsen NJ. Neprilysin activity is increased in metabolic dysfunction-associated steatotic liver disease and normalizes after bariatric surgery or GLP-1 therapy. iScience 2023; 26:108190. [PMID: 37953952 PMCID: PMC10638073 DOI: 10.1016/j.isci.2023.108190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/25/2023] [Accepted: 10/10/2023] [Indexed: 11/14/2023] Open
Abstract
Inhibitors of neprilysin improve glycemia in patients with heart failure and type 2 diabetes (T2D). The effect of weight loss by diet, surgery, or pharmacotherapy on neprilysin activity (NEPa) is unknown. We investigated circulating NEPa and neprilysin protein concentrations in obesity, T2D, metabolic dysfunction-associated steatotic liver disease (MASLD), and following bariatric surgery, or GLP-1-receptor-agonist therapy. NEPa, but not neprilysin protein, was enhanced in obesity, T2D, and MASLD. Notably, MASLD associated with NEPa independently of BMI and HbA1c. NEPa decreased after bariatric surgery with a concurrent increase in OGTT-stimulated GLP-1. Diet-induced weight loss did not affect NEPa, but individuals randomized to 52-week weight maintenance with liraglutide (1.2 mg/day) decreased NEPa, consistent with another study following 6-week liraglutide (3 mg/day). A 90-min GLP-1 infusion did not alter NEPa. Thus, MASLD may drive exaggerated NEPa, and lowered NEPa following bariatric surgery or liraglutide therapy may contribute to the reported improved cardiometabolic effects.
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Affiliation(s)
- Sasha A.S. Kjeldsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, 2400 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Lise L. Gluud
- Gastro Unit, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Mikkel P. Werge
- Gastro Unit, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
| | - Julie S. Pedersen
- Gastro Unit, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
| | - Flemming Bendtsen
- Gastro Unit, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Kleopatra Alexiadou
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London SW7 2BX, UK
| | - Tricia Tan
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London SW7 2BX, UK
| | - Signe S. Torekov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Eva W. Iepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nicole J. Jensen
- Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, 2400 Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Michael M. Richter
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, 2400 Copenhagen, Denmark
| | - Jens P. Goetze
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Clinical Biochemistry, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Jørgen Rungby
- Department of Endocrinology, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, 2400 Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Birgitte Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Joachim Holt
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Finn Gustafsson
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Cardiology, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Sten Madsbad
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Endocrinology, Copenhagen University Hospital - Hvidovre, 2650 Hvidovre, Denmark
| | - Maria S. Svane
- Gastro Unit, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Department of Endocrinology, Copenhagen University Hospital - Hvidovre, 2650 Hvidovre, Denmark
| | - Kirstine N. Bojsen-Møller
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Endocrinology, Copenhagen University Hospital - Hvidovre, 2650 Hvidovre, Denmark
| | - Nicolai J. Wewer Albrechtsen
- Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, 2400 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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Kjeldsen SAS, Thomsen MN, Skytte MJ, Samkani A, Richter MM, Frystyk J, Magkos F, Hansen E, Thomsen HS, Holst JJ, Madsbad S, Haugaard SB, Krarup T, Wewer Albrechtsen NJ. Markers of Glucagon Resistance Improve With Reductions in Hepatic Steatosis and Body Weight in Type 2 Diabetes. J Endocr Soc 2023; 7:bvad122. [PMID: 37818402 PMCID: PMC10561012 DOI: 10.1210/jendso/bvad122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Indexed: 10/12/2023] Open
Abstract
Context Hyperglucagonemia may develop in type 2 diabetes due to obesity-prone hepatic steatosis (glucagon resistance). Markers of glucagon resistance (including the glucagon-alanine index) improve following diet-induced weight loss, but the partial contribution of lowering hepatic steatosis vs body weight is unknown. Objective This work aimed to investigate the dependency of body weight loss following a reduction in hepatic steatosis on markers of glucagon resistance in type 2 diabetes. Methods A post hoc analysis was conducted from 2 previously published randomized controlled trials. We investigated the effect of weight maintenance (study 1: isocaloric feeding) or weight loss (study 2: hypocaloric feeding), both of which induced reductions in hepatic steatosis, on markers of glucagon sensitivity, including the glucagon-alanine index measured using a validated enzyme-linked immunosorbent assay and metabolomics in 94 individuals (n = 28 in study 1; n = 66 in study 2). Individuals with overweight or obesity with type 2 diabetes were randomly assigned to a 6-week conventional diabetes (CD) or carbohydrate-reduced high-protein (CRHP) diet within both isocaloric and hypocaloric feeding-interventions. Results By design, weight loss was greater after hypocaloric compared to isocaloric feeding, but both diets caused similar reductions in hepatic steatosis, allowing us to investigate the effect of reducing hepatic steatosis with or without a clinically relevant weight loss on markers of glucagon resistance. The glucagon-alanine index improved following hypocaloric, but not isocaloric, feeding, independently of macronutrient composition. Conclusion Improvements in glucagon resistance may depend on body weight loss in patients with type 2 diabetes.
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Affiliation(s)
- Sasha A S Kjeldsen
- Department of Clinical Biochemistry, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Mads N Thomsen
- Department of Endocrinology, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
| | - Mads J Skytte
- Department of Endocrinology, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
| | - Amirsalar Samkani
- Department of Endocrinology, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
| | - Michael M Richter
- Department of Clinical Biochemistry, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Jan Frystyk
- Department of Endocrinology, Odense University Hospital, Odense, 5000, Denmark
| | - Faidon Magkos
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Frederiksberg, 1958, Denmark
| | - Elizaveta Hansen
- Department of Radiology, Copenhagen University Hospital-Herlev, Herlev, 2730, Denmark
| | - Henrik S Thomsen
- Department of Radiology, Copenhagen University Hospital-Herlev, Herlev, 2730, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital-Hvidovre, Hvidovre, 2650, Denmark
| | - Steen B Haugaard
- Department of Endocrinology, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Thure Krarup
- Department of Endocrinology, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Frederiksberg, 1958, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Copenhagen University Hospital-Bispebjerg and Frederiksberg, Copenhagen, 2400, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
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8
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Richter MM, Svane MS, Kristiansen VB, Holst JJ, Madsbad S, Bojsen-Møller KN. Postprandial secretion of follistatin after gastric bypass surgery and sleeve gastrectomy. Peptides 2023; 163:170978. [PMID: 36842630 DOI: 10.1016/j.peptides.2023.170978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/14/2023] [Accepted: 02/23/2023] [Indexed: 02/28/2023]
Abstract
Follistatin is secreted from the liver and may regulate muscle growth and insulin sensitivity. Protein intake stimulates follistatin secretion, which may be mediated by increased glucagon in the context of low insulin concentrations. We investigated circulating follistatin after mixed-meals in two cohorts of patients who were part of previously published studies and had undergone bariatric surgery with either simultaneous assessment of amino acid absorption or administration of the GLP-1 receptor antagonist exendin-(9-39), which increased glucagon concentrations and impaired insulin secretion. Study 1 comprised obese matched subjects with previous Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery and unoperated controls who underwent 6-hour mixed-meal tests with intravenous and oral tracers including intrinsically labelled caseinate in the meal. Study 2 comprised obese subjects with previous RYGB who underwent two 5-hour mixed-meal tests with concomitant exendin-(9-39) or saline infusion. In study 1, the secretion of follistatin as well as the amino acid absorption was accelerated after RYGB compared with SG and controls, but the glucagon-to-C-peptide ratios did not differ between the groups. In study 2, exendin-(9-39) administration increased postprandial glucagon concentrations and lowered insulin secretion, whereas the concentration of follistatin was unchanged. In conclusion, postprandial follistatin secretion is accelerated in patients after RYGB which might be explained by an accelerated protein absorption rate rather than the glucagon-to-insulin ratio.
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Affiliation(s)
| | - Maria S Svane
- Department of Endocrinology, Hvidovre Hospital, Hvidovre, Denmark; Department of Gastrointestinal Surgery, Hvidovre Hospital, Hvidovre, Denmark
| | - Viggo B Kristiansen
- Department of Gastrointestinal Surgery, Hvidovre Hospital, Hvidovre, Denmark
| | - Jens J Holst
- Novo Nordic Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Hvidovre Hospital, Hvidovre, Denmark
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9
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Kjeldsen SAS, Richter MM, Jensen NJ, Nilsson MSD, Heinz N, Nybing JD, Linden FH, Høgh-Schmidt E, Boesen MP, Madsbad S, Vilstrup H, Schiødt FV, Møller A, Nørgaard K, Schmidt S, Rashu EB, Gluud LL, Haugaard SB, Holst JJ, Rungby J, Wewer Albrechtsen NJ. Development of a glucagon sensitivity test in humans: Pilot data and the GLUSENTIC study protocol. Peptides 2023; 161:170938. [PMID: 36596314 DOI: 10.1016/j.peptides.2022.170938] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/30/2022] [Accepted: 12/30/2022] [Indexed: 01/02/2023]
Abstract
A physiological feedback system exists between hepatocytes and the alpha cells, termed the liver-alpha cell axis and refers to the relationship between amino acid-stimulated glucagon secretion and glucagon-stimulated amino acid catabolism. Several reports indicate that non-alcoholic fatty liver disease (NAFLD) disrupts the liver-alpha cell axis, because of impaired glucagon receptor signaling (glucagon resistance). However, no experimental test exists to assess glucagon resistance in humans. The objective was to develop an experimental test to determine glucagon sensitivity with respect to amino acid and glucose metabolism in humans. The proposed glucagon sensitivity test (comprising two elements: 1) i.v. injection of 0.2 mg glucagon and 2) infusion of mixed amino acids 331 mg/hour/kg) is based on nine pilot studies which are presented. Calculation of a proposed glucagon sensitivity index with respect to amino acid catabolism is also described. Secondly, we describe a complete study protocol (GLUSENTIC) according to which the glucagon sensitivity test will be applied in a cross-sectional study currently taking place. 65 participants including 20 individuals with a BMI 18.6-25 kg/m2, 30 individuals with a BMI ≥ 25-40 kg/m2, and 15 individuals with type 1 diabetes with a BMI between 18.6 and 40 kg/m2 will be included. Participants will be grouped according to their degree of hepatic steatosis measured by whole-liver magnetic resonance imaging (MRI). The primary outcome measure will be differences in the glucagon sensitivity index between individuals with and without hepatic steatosis. Developing a glucagon sensitivity test and index may provide insight into the physiological and pathophysiological mechanism of glucagon action and glucagon-based therapies.
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Affiliation(s)
- Sasha A S Kjeldsen
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Bispebjerg, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Michael M Richter
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Bispebjerg, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicole J Jensen
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Malin S D Nilsson
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Niklas Heinz
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Janus D Nybing
- Department of Radiology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Frederik H Linden
- Department of Radiology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Erik Høgh-Schmidt
- Department of Radiology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Mikael P Boesen
- Department of Radiology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Hvidovre University Hospital, Hvidovre, Denmark
| | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Andreas Møller
- Department of Gastroenterology and Gastrointestinal Surgery, Hvidovre University Hospital, Hvidovre, Denmark
| | - Kirsten Nørgaard
- Institute of Clinical Medicine, Faculty of Health Science, University of Copenhagen, Denmark; Steno Diabetes Center Copenhagen, Herlev, Denmark
| | | | - Elias B Rashu
- Department of Gastroenterology and Gastrointestinal Surgery, Hvidovre University Hospital, Hvidovre, Denmark
| | - Lise L Gluud
- Department of Gastroenterology and Gastrointestinal Surgery, Hvidovre University Hospital, Hvidovre, Denmark; Institute of Clinical Medicine, Faculty of Health Science, University of Copenhagen, Denmark
| | - Steen B Haugaard
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark; Institute of Clinical Medicine, Faculty of Health Science, University of Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Rungby
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark; Steno Diabetes Center Copenhagen, Herlev, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Bispebjerg, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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10
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Wewer Albrechtsen NJ, Møller A, Martinussen C, Gluud LL, Rashu EB, Richter MM, Plomgaard P, Goetze JP, Kjeldsen S, Hansen LH, Gustafsson F, Deacon CF, Holst JJ, Madsbad S, Bojsen‐Møller KN. Acute effects on glucose tolerance by neprilysin inhibition in patients with type 2 diabetes. Diabetes Obes Metab 2022; 24:2017-2026. [PMID: 35676803 PMCID: PMC9545540 DOI: 10.1111/dom.14789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/24/2022] [Accepted: 06/06/2022] [Indexed: 12/11/2022]
Abstract
AIMS Sacubitril/valsartan is a neprilysin-inhibitor/angiotensin II receptor blocker used for the treatment of heart failure. Recently, a post-hoc analysis of a 3-year randomized controlled trial showed improved glycaemic control with sacubitril/valsartan in patients with heart failure and type 2 diabetes. We previously reported that sacubitril/valsartan combined with a dipeptidyl peptidase-4 inhibitor increases active glucagon-like peptide-1 (GLP-1) in healthy individuals. We now hypothesized that administration of sacubitril/valsartan with or without a dipeptidyl peptidase-4 inhibitor would lower postprandial glucose concentrations (primary outcome) in patients with type 2 diabetes via increased active GLP-1. METHODS We performed a crossover trial in 12 patients with obesity and type 2 diabetes. A mixed meal was ingested following five respective interventions: (a) a single dose of sacubitril/valsartan; (b) sitagliptin; (c) sacubitril/valsartan + sitagliptin; (d) control (no treatment); and (e) valsartan alone. Glucose, gut and pancreatic hormone responses were measured. RESULTS Postprandial plasma glucose increased by 57% (incremental area under the curve 0-240 min) (p = .0003) and increased peak plasma glucose by 1.7 mM (95% CI: 0.6-2.9) (p = .003) after sacubitril/valsartan compared with control, whereas postprandial glucose levels did not change significantly after sacubitril/valsartan + sitagliptin. Glucagon, GLP-1 and C-peptide concentrations increased after sacubitril/valsartan, but insulin and glucose-dependent insulinotropic polypeptide did not change. CONCLUSIONS The glucose-lowering effects of long-term sacubitril/valsartan treatment reported in patients with heart failure and type 2 diabetes may not depend on changes in entero-pancreatic hormones. Neprilysin inhibition results in hyperglucagonaemia and this may explain the worsen glucose tolerance observed in this study. CLINICALTRIALS gov (NCT03893526).
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Affiliation(s)
- Nicolai J. Wewer Albrechtsen
- Department of Clinical Biochemistry, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- NNF Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg HospitalUniversity of CopenhagenCopenhagenDenmark
| | - Andreas Møller
- Department of EndocrinologyCopenhagen University Hospital HvidovreHvidovreDenmark
| | | | - Lise L. Gluud
- Gastrounit, Copenhagen University Hospital HvidovreHvidovreDenmark
| | - Elias B. Rashu
- Gastrounit, Copenhagen University Hospital HvidovreHvidovreDenmark
| | - Michael M. Richter
- Department of Clinical Biochemistry, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
| | - Peter Plomgaard
- Department of Clinical Biochemistry, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
- Department of Clinical Medicine, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Jens P. Goetze
- Department of Clinical Biochemistry, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Sasha Kjeldsen
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- NNF Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Lasse Holst Hansen
- Department of Clinical Biochemistry, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Finn Gustafsson
- Department of Cardiology, Heart CentreRigshospitalet, University of CopenhagenCopenhagenDenmark
| | - Carolyn F. Deacon
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- School of Biomedical SciencesUlster UniversityColeraineUK
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Sten Madsbad
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg HospitalUniversity of CopenhagenCopenhagenDenmark
| | - Kirstine N. Bojsen‐Møller
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg HospitalUniversity of CopenhagenCopenhagenDenmark
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11
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Maruszczak K, Rasmussen C, Ceutz FR, Ørgaard A, Elmelund E, Richter MM, Holst JJ, Winther-Sørensen M, Wewer Albrechtsen NJ. Arginine-induced glucagon secretion and glucagon-induced enhancement of amino acid catabolism are not influenced by ambient glucose levels in mice. Am J Physiol Endocrinol Metab 2022; 323:E207-E214. [PMID: 35830690 DOI: 10.1152/ajpendo.00122.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Amino acids stimulate the secretion of glucagon, and glucagon receptor signaling regulates amino acid catabolism via ureagenesis, together constituting the liver-α cell axis. Impairment of the liver-α cell axis is observed in metabolic diseases such as diabetes. It is, however, unknown whether glucose affects the liver-α cell axis. We investigated the role of glucose on the liver-α cell axis in vivo and ex vivo. The isolated perfused mouse pancreas was used to evaluate the direct effect of low (3.5 mmol/L) and high (15 mmol/L) glucose levels on amino acid (10 mmol/L arginine)-induced glucagon secretion. High glucose levels alone lowered glucagon secretion, but the amino acid-induced glucagon responses were similar in high and low glucose conditions (P = 0.38). The direct effect of glucose on glucagon and amino acid-induced ureagenesis was assessed using isolated perfused mouse livers stimulated with a mixture of amino acids (VaminR, 10 mmol/L) and glucagon (10 nmol/L) during high and low glucose conditions. Urea production increased robustly but was independent of glucose levels (P = 0.95). To investigate the whole body effects of glucose on the liver-α cell axis, four groups of mice received intraperitoneal injections of glucose-Vamin (2 g/kg, + 3.5 µmol/g, respectively, G/V), saline-Vamin (S/V), glucose-saline (G/S), or saline-saline (S/S). Blood glucose did not differ significantly between G/S and G/V groups. Levels of glucagon and amino acids were similar in the G/V and S/V groups (P = 0.28). Amino acids may overrule the inhibitory effect of glucose on glucagon secretion and the liver-α cell axis may operate independently of glucose in mice.NEW & NOTEWORTHY Glucagon is an essential regulator of our metabolism. Recent evidence suggests that the physiological actions of glucagon reside in amino acid catabolism in the so-called liver-α cell axis, in which amino acids stimulate glucagon secretion and glucagon enhances hepatic amino acid catabolism. Here, it is demonstrated that this feedback system is independent of glycemia possibly explaining why hyperglycemia in diabetes may not suppress α cell secretion.
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Affiliation(s)
- Katharina Maruszczak
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
- Obesity Research Unit, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Christine Rasmussen
- Department for Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Frederik R Ceutz
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Ørgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emilie Elmelund
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael M Richter
- Department for Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department for Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department for Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
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12
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Richter MM, Galsgaard KD, Elmelund E, Knop FK, Suppli MP, Holst JJ, Winther-Sørensen M, Kjeldsen SA, Wewer Albrechtsen NJ. The Liver-α-Cell Axis in Health and in Disease. Diabetes 2022; 71:1852-1861. [PMID: 35657688 PMCID: PMC9862287 DOI: 10.2337/dbi22-0004] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/19/2022] [Indexed: 02/05/2023]
Abstract
Glucagon and insulin are the main regulators of blood glucose. While the actions of insulin are extensively mapped, less is known about glucagon. Besides glucagon's role in glucose homeostasis, there are additional links between the pancreatic α-cells and the hepatocytes, often collectively referred to as the liver-α-cell axis, that may be of importance for health and disease. Thus, glucagon receptor antagonism (pharmacological or genetic), which disrupts the liver-α-cell axis, results not only in lower fasting glucose but also in reduced amino acid turnover and dyslipidemia. Here, we review the actions of glucagon on glucose homeostasis, amino acid catabolism, and lipid metabolism in the context of the liver-α-cell axis. The concept of glucagon resistance is also discussed, and we argue that the various elements of the liver-α-cell axis may be differentially affected in metabolic diseases such as diabetes, obesity, and nonalcoholic fatty liver disease (NAFLD). This conceptual rethinking of glucagon biology may explain why patients with type 2 diabetes have hyperglucagonemia and how NAFLD disrupts the liver-α-cell axis, compromising the normal glucagon-mediated enhancement of substrate-induced amino acid turnover and possibly fatty acid β-oxidation. In contrast to amino acid catabolism, glucagon-induced glucose production may not be affected by NAFLD, explaining the diabetogenic effect of NAFLD-associated hyperglucagonemia. Consideration of the liver-α-cell axis is essential to understanding the complex pathophysiology underlying diabetes and other metabolic diseases.
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Affiliation(s)
- Michael M. Richter
- Department of Clinical Biochemistry, Diagnostic Center, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine D. Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emilie Elmelund
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K. Knop
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Herlev, Denmark
| | - Malte P. Suppli
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Winther-Sørensen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sasha A.S. Kjeldsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J. Wewer Albrechtsen
- Department of Clinical Biochemistry, Diagnostic Center, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Copenhagen University Hospital—Bispebjerg and Frederiksberg Hospital, Bispebjerg, Denmark
- Corresponding author: Nicolai J. Wewer Albrechtsen,
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13
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Abstract
Context Fibroblast growth factor 21 (FGF21), follistatin, angiopoietin-like 4 (ANGPTL4), and growth differential factor 15 (GDF15) are regulated by energy metabolism. Recent findings in humans demonstrate that fructose ingestion increases circulating FGF21, with increased response in conditions of insulin resistance. Objective This study examines the acute effect of fructose and somatostatin on circulating FGF21, follistatin, ANGPTL4, and GDF15 in humans. Methods Plasma FGF21, follistatin, ANGPTL4, and GDF15 concentrations were measured in response to oral ingestion of 75 g of fructose in 10 young healthy males with and without a 15-minute infusion of somatostatin to block insulin secretion. A control infusion of somatostatin was also performed in the same subjects. Results Following fructose ingestion, plasma FGF21 peaked at 3.7-fold higher than basal concentration (P < 0.05), and it increased 4.9-fold compared with basal concentration (P < 0.05) when somatostatin was infused. Plasma follistatin increased 1.8-fold after fructose ingestion (P < 0.05), but this increase was blunted by concomitant somatostatin infusion. For plasma ANGPTL4 and GDF15, no increases were obtained following fructose ingestion. Infusion of somatostatin alone slightly increased plasma FGF21 and follistatin. Conclusion Here we show that in humans (1) the fructose-induced increase in plasma FGF21 was enhanced when somatostatin was infused, suggesting an inhibitory role of insulin on the fructose-induced FGF21 increase; (2) fructose ingestion also increased plasma follistatin, but somatostatin infusion blunted the increase; and (3) fructose ingestion had no stimulating effect on ANGPTL4 and GDF15 levels, demonstrating differences in the hepatokine response to fructose ingestion.
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Affiliation(s)
- Michael M Richter
- Department of Clinical Biochemistry, Rigshospitalet, DK-2100 Copenhagen, Denmark
| | - Peter Plomgaard
- Department of Clinical Biochemistry, Rigshospitalet, DK-2100 Copenhagen, Denmark.,The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Department of Infectious Diseases and CMRC, Rigshospitalet, DK-2100 Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
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Richter MM, Barnes BM, O'Reilly KM, Fenn AM, Buck CL. The influence of androgens on hibernation phenology of free-living male arctic ground squirrels. Horm Behav 2017; 89:92-97. [PMID: 27986541 PMCID: PMC5359051 DOI: 10.1016/j.yhbeh.2016.12.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 12/12/2016] [Indexed: 11/25/2022]
Abstract
Free-living ground squirrel species are sexually dimorphic in hibernation phenology. The underlying causes of these differences are not yet known. Androgens, testosterone (T) in particular, inhibit hibernation. To determine the influence of endogenous androgens on annual timing of hibernation we first measured circulating levels of T and dehydroepiandrosterone (DHEA), an adrenal androgen implicated in non-mating season aggression in other species, in free-living male arctic ground squirrels (Urocitellus parryii, AGS). We also manipulated endogenous androgen levels by surgical castration, and consequently compared body temperature records from intact (n=24) and castrated (n=9) males to elucidate the influence of endogenous androgens on annual body temperature cycles. The highest T levels (0.53±0.10ng/mL) were in reproductively mature male AGS in spring; whereas, both immature males in spring and all males in late summer had T levels an order of magnitude lower (0.07±0.01 and 0.06±0.00ng/mL, respectively). DHEA levels were higher in males during the late summer compared to reproductively mature males in spring (120.6±18.9 and 35.9±2.3pg/mL, respectively). Eliminating gonadal androgens via castration resulted in males delaying euthermy by extending heterothermy significantly in spring (Apr 22 ±2.9) than reproductive males (Mar 28 ±3.9) but did not change the timing of hibernation onset (castrate: Oct 12 ±1.0 vs. intact: Oct 3 ±3.1). We conclude that while androgens play a significant role in spring hibernation phenology of males, their role in fall hibernation onset is unclear.
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Affiliation(s)
- M M Richter
- Western Kentucky University, 1906 College Heights Blvd, Bowling Green, KY 42101, USA.
| | - B M Barnes
- Institute of Arctic Biology, University of Alaska Fairbanks, Alaska 99775, United States.
| | - K M O'Reilly
- Department of Biology, University of Portland, Oregon 97203, United States.
| | - A M Fenn
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114-2506, United States.
| | - C L Buck
- Department of Biological Sciences and Center for Bioengineering Innovation, Northern Arizona University, Flagstaff, 86001 Arizona.
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Richter MM, von Mammen S. Eine Zukunftsperspektive der Künstlichen Intelligenz am Beispiel menschlicher Kommunikation mit Rechnern. Künstl Intell 2011. [DOI: 10.1007/s13218-011-0125-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
A 24-year-old anorexic patient with cormobid symptoms of depression was treated for depression with repetitive transcranial magnetic stimulation (rTMS) rather than with psychopharmacotherapy, due to her poor physical condition. The depressive symptomatology significantly improved in correlation with two rTMS cycles but occurred again within 2 weeks. A third successful cycle was then followed by a maintenance rTMS protocol with the patient going into remission from depression. This case illustrates that rTMS may be considered as a therapeutic option for comorbid depression in anorectic patients.
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Affiliation(s)
- S Kamolz
- Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie, Klinikum der Bayerischen Julius-Maximilians-Universität Würzburg, Füchslein Str. 15, 97080, Würzburg, Deutschland
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von Wangenheim A, Bertoldi RF, Abdala DD, Richter MM, Priese L, Schmitt F. Fast two-step segmentation of natural color scenes using hierarchical region-growing and a Color-Gradient Network. J Braz Comp Soc 2008. [DOI: 10.1007/bf03192570] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Abstract
We present evaluation results with focus on combined image and efficiency performance of the Gradient Network Method to segment color images, especially images showing outdoor scenes. A brief review of the techniques, Gradient Network Method and Color Structure Code, is also presented. Different region-growing segmentation results are compared against ground truth images using segmentation evaluation indices Rand and Bipartite Graph Matching. These results are also confronted with other well established segmentation methods (EDISON and JSEG). Our preliminary results show reasonable performance in comparison to several state-of-art segmentation techniques, while also showing very promising results comparatively in the terms of efficiency, indicating the applicability of our solution to real time problems.
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Wangenheim AV, Bertoldi RF, Abdala DD, Richter MM, Priese L, Schmitt F. Fast two-step segmentation of natural color scenes using hierarchical region-growing and a color-gradient network. J Braz Comp Soc 2008. [DOI: 10.1590/s0104-65002008000400004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Fallgatter AJ, Ehlis AC, Richter MM, Schecklmann M, Plichta MM. Near-infrared spectroscopy (NIRS) – a promising brain imaging method in Psychiatry? KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Fallgatter AJ, Richter MM, Schecklmann M, Plichta MM, Ehlis AC. Endophenotypic measures of altered inhibitory brain processes in ADHD. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Richter MM, Brundage CM, Taylor BE. Effect of thyrotropin‐releasing hormone on neuroventilation in bullfrogs. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.954.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- M M Richter
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAK
| | - C M Brundage
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAK
| | - B E Taylor
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAK
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Herwig U, Fallgatter AJ, Höppner J, Eschweiler GW, Kron M, Hajak G, Padberg F, Naderi-Heiden A, Abler B, Eichhammer P, Grossheinrich N, Hay B, Kammer T, Langguth B, Laske C, Plewnia C, Richter MM, Schulz M, Unterecker S, Zinke A, Spitzer M, Schönfeldt-Lecuona C. Antidepressant effects of augmentative transcranial magnetic stimulation: randomised multicentre trial. Br J Psychiatry 2007; 191:441-8. [PMID: 17978325 DOI: 10.1192/bjp.bp.106.034371] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a new treatment option for depression. Previous studies were performed with low sample sizes in single centres and reported heterogeneous results. AIMS To investigate the efficacy of rTMS as augmentative treatment in depression. METHOD In a randomised, double-blind, sham-controlled multicentre trial 127 patients with moderate to severe depressive episodes were randomly assigned to real or sham stimulation for 3 weeks in addition to simultaneously initiated antidepressant medication. RESULTS We found no difference in the responder rates of the real and the sham treatment groups (31% in each) or in the decrease of the scores on the depression rating scales. CONCLUSIONS The data do not support previous reports from smaller samples indicating an augmenting or accelerating antidepressant effect of rTMS. Further exploration of the possible efficacy of other stimulation protocols or within selected sub-populations of patients is necessary.
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Affiliation(s)
- U Herwig
- Psychiatric University Hospital, University of Zürich, Lenggstrasse 31, Zürich, Switzerland.
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Plichta MM, Herrmann MJ, Baehne CG, Ehlis AC, Richter MM, Pauli P, Fallgatter AJ. Event-related functional near-infrared spectroscopy (fNIRS) based on craniocerebral correlations: reproducibility of activation? Hum Brain Mapp 2007; 28:733-41. [PMID: 17080439 PMCID: PMC6871457 DOI: 10.1002/hbm.20303] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The purpose of the present study was to assess the retest reliability of cortical activation detected by event-related functional near-infrared spectroscopy (fNIRS) based on craniocerebral correlations. Isolated functional activation was evoked in the motor cortex by a periodically performed finger-tapping task. During 44-channel fNIRS recording, 12 subjects performed 30 trials of right and left index finger tapping in two sessions. The retest interval was set to 3 weeks. Simple correlations of the contrast t-values supplemented by scatterplots, channel-wise intraclass correlation coefficients (ICC), as well as reproducibility indices for the size and the location of the detected activation were calculated. The results at the group level showed sufficient single measure ICCs (up to 0.80) and excellent reproducibility of the size and the location (up to 89% were reproducible). Comparisons of the intersession group amplitudes demonstrate that the fNIRS signals were stable across time in a retest study design: the number of significant differences was less than randomly occurring false-positive activated channels if an alpha level of 5% is chosen. Effect size analyses indicated that the intersession amplitude differences are small (mean < 0.25). For deoxyhemoglobin and oxyhemoglobin distinct statistical power profiles were revealed regarding the activation vs. baseline contrast as well as the intersession amplitude differences, indicating a higher sensitivity of deoxyhemoglobin for local hemodynamic changes. The results suggest that sensorimotor activation assessed by event-related fNIRS based on craniocerebral correlations is sufficiently reproducible at the group level.
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Affiliation(s)
- M M Plichta
- University of Wurzburg, University Hospital of Psychiatry and Psychotherapy, Laboratory for Psychophysiology and Functional Imaging, Wurzburg, Germany.
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Plichta MM, Herrmann MJ, Ehlis AC, Baehne CG, Richter MM, Fallgatter AJ. Event-related visual versus blocked motor task: detection of specific cortical activation patterns with functional near-infrared spectroscopy. Neuropsychobiology 2006; 53:77-82. [PMID: 16511338 DOI: 10.1159/000091723] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2004] [Accepted: 10/04/2005] [Indexed: 11/19/2022]
Abstract
The purpose of this study was to investigate the regional specificity of multi-channel functional near-infrared spectroscopy (fNIRS) in the detection of cortical activation in humans. Therefore, brain activation evoked by a visual as well as a motor task was examined using 52-channel fNIRS. Analyses demonstrated an isolated activation in the occipital area during visual stimulation, whereas other regions exhibited little or no activation. Analyses of the motor task data clearly identified a differential activation pattern. The observation of an extensive cortical area by multi-channel measurement during two different tasks made it possible to examine the extent to which fNIRS measurements detect regional specific activations. We conclude that fNIRS measurements can detect regionally isolated cortical activation.
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Affiliation(s)
- M M Plichta
- Laboratory for Psychophysiology and Functional Imaging, University Hospital of Psychiatry and Psychotherapy Würzburg, Würzburg, Germany.
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Plichta MM, Herrmann MJ, Baehne CG, Ehlis AC, Richter MM, Pauli P, Fallgatter AJ. Event-related functional near-infrared spectroscopy (fNIRS): Are the measurements reliable? Neuroimage 2006; 31:116-24. [PMID: 16446104 DOI: 10.1016/j.neuroimage.2005.12.008] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 12/06/2005] [Accepted: 12/07/2005] [Indexed: 11/27/2022] Open
Abstract
The purpose of the present study was to investigate the retest reliability of event-related functional near-infrared spectroscopy (fNIRS). Therefore, isolated functional activation was evoked in the occipital cortex by a periodic checkerboard stimulation. During a 52-channel fNIRS recording, 12 subjects underwent 60 trials of visual stimulation in two sessions. The retest interval was set to 3 weeks. Linear correlations of the contrast t values supplemented by scatter plots, channel-wise intraclass correlation coefficients (ICC) as well as reproducibility indices for the quantity of activated channels (RQUANTITY) and the location (ROVERLAP) of the detected activation were calculated. The results at the group level showed good reliability in terms of the single measure ICCs (up to 0.84) and excellent reproducibility quantified by RQUANTITY and ROVERLAP (up to 96% of the quantity and the location were reproducible), whereas the results at the single subjects' level were mediocre. Furthermore, the reliability assessed by single measurement ICCs improved if regarded at a cluster level.
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Affiliation(s)
- M M Plichta
- Department of Psychiatry and Psychotherapy, Laboratory for Psychophysiology and Functional Imaging, University Hospital Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany.
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Abstract
The electrochemical and electrochemiluminescence (ECL) properties of Cu[dmp]2+ (dmp = 2,9-dimethyl-1,10-phenanthroline) have been investigated. ECL has been observed for Cu(dmp)2+ in aqueous, nonaqueous, and mixed solvent solutions using tri-n-propylamine as an oxidative-reductive coreactant. The ECL intensity peaks at potential corresponding to oxidation of both the coreactant and Cu(dmp)2+. The peak potential corresponding to maximum ECL emission is approximately 500 mV more anodic than corresponding oxidative peak potentials, indicating that the ECL emission may be due to the formation of either the *Cu(dmp)2+ metal-to-ligand charge-transfer excited state or an excited-state product of Cu(dmp)2+ oxidation. ECL efficiencies (phiecl = photons generated per redox event) are solvent-dependent (phiecl (CH3CN) > phiecl (50:50 (v/v) CH3CN:H20) > phiecl (H2O)) and correspond fairly well with photoluminescence efficiencies. Increased ECL efficiencies (> or = 50-fold) are observed in the presence of the nonionic surfactant Triton X-100.
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Affiliation(s)
- J McCall
- Department of Chemistry, Southwest Missouri State University, Springfield 65804, USA
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Factor B, Muegge B, Workman S, Bolton E, Bos J, Richter MM. Surfactant chain length effects on the light emission of tris(2,2'-bipyridyl)ruthenium(II)/ tripropylamine electrogenerated chemiluminescence. Anal Chem 2001; 73:4621-4. [PMID: 11605839 DOI: 10.1021/ac010698e] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of nonionic surfactant chain length on the properties of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+) where bpy = 2,2'-bipyridine) electrochemiluminescence (ECL) have been investigated. The electrochemistry, photophysics, and ECL of Ru(bpy)3(2+) in the presence of a series of nonionic surfactants are reported (Triton X-100, 114, 165, 405, 305, and 705-70). These surfactants differ in the number of poly(ethylene oxide) units incorporated into the surfactant molecule. The anodic oxidation of Ru(bpy)3(2+) produces ECL in the presence of tri-n-propylamine (TPrA) in aqueous surfactant solution. Increases in ECL efficiency (> or = 5-fold) and TPrA oxidation current (> or = 2-fold) have been observed in surfactant media. Slight decreases in ECL intensity are observed as the chain length of the nonionic surfactant increases. The data supports adsorption of surfactant on the electrode surface, thus facilitating TPrA and Ru(bpy)3(2+) oxidation and leading to higher ECL efficiencies.
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Affiliation(s)
- B Factor
- Department of Chemistry, Southwest Missouri State University, Springfield 65804, USA
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Workman S, Richter MM. The effects of nonionic surfactants on the tris(2,2'-bipyridyl)ruthenium(II)--tripropylamine electrochemiluminescence system. Anal Chem 2000; 72:5556-61. [PMID: 11101231 DOI: 10.1021/ac000800s] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The electrochemistry and electrogenerated chemiluminescence (ECL) of Ru(bpy)3(2+) (bpy = 2,2'-bipyridyl) were studied in the presence of the nonionic surfactants Triton X-100, Thesit, and Nonidet P40. The anodic oxidation of Ru(bpy)3(2+) produces ECL in the presence of tri-n-propylamine in both aqueous and surfactant solutions. Increases in both ECL efficiency (> or =8-fold) and duration of the ECL signal were observed in surfactant media. A shift to lower energies of the Ru(bpy)3(2+) ECL emission by approximately 8 nm was also observed. The one-electron oxidation of Ru(bpy)3(2+) to Ru(bpy)3(3t) occurs at + 1.03 V vs Ag/AgCl in aqueous buffered (0.2 M potassium phosphate) solution as found by square wave voltammetry. This potential did not shift in surfactant systems, indicating that the redshifts in ECL emission are due to stabilization of ligand pi* orbitals in the metal-to-ligand charge-transfer excited state. These results are consistent with hydrophobic interactions between Ru(bpy)3(2+) and the nonionic surfactants.
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Affiliation(s)
- S Workman
- Department of Chemistry, Southwest Missouri State University, Springfield, 65804, USA
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