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Alamshah A, McGavigan AK, Spreckley E, Kinsey-Jones JS, Amin A, Tough IR, O'Hara HC, Moolla A, Banks K, France R, Hyberg G, Norton M, Cheong W, Lehmann A, Bloom SR, Cox HM, Murphy KG. L-arginine promotes gut hormone release and reduces food intake in rodents. Diabetes Obes Metab 2016; 18:508-18. [PMID: 26863991 PMCID: PMC4982043 DOI: 10.1111/dom.12644] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [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: 11/13/2015] [Revised: 01/31/2016] [Accepted: 02/07/2016] [Indexed: 12/14/2022]
Abstract
AIMS To investigate the anorectic effect of L-arginine (L-Arg) in rodents. METHODS We investigated the effects of L-Arg on food intake, and the role of the anorectic gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), the G-protein-coupled receptor family C group 6 member A (GPRC6A) and the vagus nerve in mediating these effects in rodents. RESULTS Oral gavage of L-Arg reduced food intake in rodents, and chronically reduced cumulative food intake in diet-induced obese mice. Lack of the GPRC6A in mice and subdiaphragmatic vagal deafferentation in rats did not influence these anorectic effects. L-Arg stimulated GLP-1 and PYY release in vitro and in vivo. Pharmacological blockade of GLP-1 and PYY receptors did not influence the anorectic effect of L-Arg. L-Arg-mediated PYY release modulated net ion transport across the gut mucosa. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of L-Arg suppressed food intake in rats. CONCLUSIONS L-Arg reduced food intake and stimulated gut hormone release in rodents. The anorectic effect of L-Arg is unlikely to be mediated by GLP-1 and PYY, does not require GPRC6A signalling and is not mediated via the vagus. I.c.v. and i.p. administration of L-Arg suppressed food intake in rats, suggesting that L-Arg may act on the brain to influence food intake. Further work is required to determine the mechanisms by which L-Arg suppresses food intake and its utility in the treatment of obesity.
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MESH Headings
- Animals
- Appetite Depressants/administration & dosage
- Appetite Depressants/adverse effects
- Appetite Depressants/pharmacology
- Appetite Depressants/therapeutic use
- Arginine/administration & dosage
- Arginine/adverse effects
- Arginine/therapeutic use
- Cells, Cultured
- Dietary Supplements/adverse effects
- Energy Intake/drug effects
- Energy Metabolism/drug effects
- Gastrointestinal Agents/administration & dosage
- Gastrointestinal Agents/adverse effects
- Gastrointestinal Agents/pharmacology
- Gastrointestinal Agents/therapeutic use
- Glucagon-Like Peptide 1/agonists
- Glucagon-Like Peptide 1/blood
- Glucagon-Like Peptide 1/metabolism
- In Vitro Techniques
- Injections, Intraperitoneal
- Injections, Intraventricular
- Intestinal Mucosa/cytology
- Intestinal Mucosa/drug effects
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/pathology
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Obesity/diet therapy
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- Peptide YY/agonists
- Peptide YY/blood
- Peptide YY/metabolism
- Random Allocation
- Rats, Wistar
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Weight Loss/drug effects
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Affiliation(s)
- A Alamshah
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A K McGavigan
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - E Spreckley
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - J S Kinsey-Jones
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A Amin
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - I R Tough
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - H C O'Hara
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A Moolla
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - K Banks
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - R France
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - G Hyberg
- AstraZeneca R&D, Mölndal, Sweden
| | - M Norton
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - W Cheong
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A Lehmann
- AstraZeneca R&D, Mölndal, Sweden
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - S R Bloom
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - H M Cox
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - K G Murphy
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
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McGavigan AK, O'Hara HC, Amin A, Kinsey-Jones J, Spreckley E, Alamshah A, Agahi A, Banks K, France R, Hyberg G, Wong C, Bewick GA, Gardiner JV, Lehmann A, Martin NM, Ghatei MA, Bloom SR, Murphy KG. L-cysteine suppresses ghrelin and reduces appetite in rodents and humans. Int J Obes (Lond) 2014; 39:447-55. [PMID: 25219528 PMCID: PMC4276721 DOI: 10.1038/ijo.2014.172] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 08/28/2014] [Accepted: 09/08/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND High-protein diets promote weight loss and subsequent weight maintenance, but are difficult to adhere to. The mechanisms by which protein exerts these effects remain unclear. However, the amino acids produced by protein digestion may have a role in driving protein-induced satiety. METHODS We tested the effects of a range of amino acids on food intake in rodents and identified l-cysteine as the most anorexigenic. Using rodents we further studied the effect of l-cysteine on food intake, behaviour and energy expenditure. We proceeded to investigate its effect on neuronal activation in the hypothalamus and brainstem before investigating its effect on gastric emptying and gut hormone release. The effect of l-cysteine on appetite scores and gut hormone release was then investigated in humans. RESULTS l-Cysteine dose-dependently decreased food intake in both rats and mice following oral gavage and intraperitoneal administration. This effect did not appear to be secondary to behavioural or aversive side effects. l-Cysteine increased neuronal activation in the area postrema and delayed gastric emptying. It suppressed plasma acyl ghrelin levels and did not reduce food intake in transgenic ghrelin-overexpressing mice. Repeated l-cysteine administration decreased food intake in rats and obese mice. l-Cysteine reduced hunger and plasma acyl ghrelin levels in humans. CONCLUSIONS Further work is required to determine the chronic effect of l-cysteine in rodents and humans on appetite and body weight, and whether l-cysteine contributes towards protein-induced satiety.
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Affiliation(s)
- A K McGavigan
- Department of Investigative Medicine, Imperial College London, London, UK
| | - H C O'Hara
- Department of Investigative Medicine, Imperial College London, London, UK
| | - A Amin
- Department of Investigative Medicine, Imperial College London, London, UK
| | - J Kinsey-Jones
- Department of Investigative Medicine, Imperial College London, London, UK
| | - E Spreckley
- Department of Investigative Medicine, Imperial College London, London, UK
| | - A Alamshah
- Department of Investigative Medicine, Imperial College London, London, UK
| | - A Agahi
- Department of Investigative Medicine, Imperial College London, London, UK
| | - K Banks
- Department of Investigative Medicine, Imperial College London, London, UK
| | - R France
- Department of Investigative Medicine, Imperial College London, London, UK
| | - G Hyberg
- AstraZeneca R&D, Mölndal, Sweden
| | - C Wong
- Department of Investigative Medicine, Imperial College London, London, UK
| | - G A Bewick
- 1] Department of Investigative Medicine, Imperial College London, London, UK [2] Division of Diabetes & Nutritional Sciences, King's College London, London, UK
| | - J V Gardiner
- Department of Investigative Medicine, Imperial College London, London, UK
| | - A Lehmann
- 1] AstraZeneca R&D, Mölndal, Sweden [2] NextRx, Gothenburg, Sweden
| | - N M Martin
- Department of Investigative Medicine, Imperial College London, London, UK
| | - M A Ghatei
- Department of Investigative Medicine, Imperial College London, London, UK
| | - S R Bloom
- Department of Investigative Medicine, Imperial College London, London, UK
| | - K G Murphy
- Department of Investigative Medicine, Imperial College London, London, UK
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Beale KE, Kinsey-Jones JS, Gardiner JV, Harrison EK, Thompson EL, Hu MH, Sleeth ML, Sam AH, Greenwood HC, McGavigan AK, Dhillo WS, Mora JM, Li XF, Franks S, Bloom SR, O'Byrne KT, Murphy KG. The physiological role of arcuate kisspeptin neurons in the control of reproductive function in female rats. Endocrinology 2014; 155:1091-8. [PMID: 24424033 PMCID: PMC3929743 DOI: 10.1210/en.2013-1544] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Kisspeptin plays a pivotal role in pubertal onset and reproductive function. In rodents, kisspeptin perikarya are located in 2 major populations: the anteroventral periventricular nucleus and the hypothalamic arcuate nucleus (ARC). These nuclei are believed to play functionally distinct roles in the control of reproduction. The anteroventral periventricular nucleus population is thought to be critical in the generation of the LH surge. However, the physiological role played by the ARC kisspeptin neurons remains to be fully elucidated. We used bilateral stereotactic injection of recombinant adeno-associated virus encoding kisspeptin antisense into the ARC of adult female rats to investigate the physiological role of kisspeptin neurons in this nucleus. Female rats with kisspeptin knockdown in the ARC displayed a significantly reduced number of both regular and complete oestrous cycles and significantly longer cycles over the 100-day period of the study. Further, kisspeptin knockdown in the ARC resulted in a decrease in LH pulse frequency. These data suggest that maintenance of ARC-kisspeptin levels is essential for normal pulsatile LH release and oestrous cyclicity.
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Affiliation(s)
- K E Beale
- Section of Investigative Medicine (K.E.B., J.S.K.-J., J.V.G., E.K.H., E.L.T., M.L.S., A.H.S., H.C.G., A.K.M., W.S.D., S.R.B., K.G.M.) and Institute of Reproductive and Developmental Biology (J.M.M., S.F.), Imperial College London, London W12 0NN, United Kingdom; and Division of Women's Health (M.H.H., X.F.L., K.T.O.), School of Medicine, King's College London, London SE1 1UL, United Kingdom
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