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Ruze R, Xu Q, Liu G, Li Y, Chen W, Cheng Z, Xiong Y, Liu S, Zhang G, Hu S, Yan Z. Central GLP-1 contributes to improved cognitive function and brain glucose uptake after duodenum-jejunum bypass on obese and diabetic rats. Am J Physiol Endocrinol Metab 2021; 321:E392-E409. [PMID: 34370593 DOI: 10.1152/ajpendo.00126.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/29/2021] [Indexed: 12/19/2022]
Abstract
The improvement of cognitive function following bariatric surgery has been highlighted, yet its underlying mechanisms remain elusive. Finding the improved brain glucose uptake of patients after Roux-en-Y gastric bypass (RYGB), duodenum-jejunum bypass (DJB), and sham surgery (Sham) were performed on obese and diabetic Wistar rats, and intracerebroventricular (ICV) injection of glucagon-like peptide-1 (GLP-1) analog liraglutide (Lira), antagonist exendin-(9-39) (Exe-9), and the viral-mediated GLP-1 receptor (Glp-1r) knockdown (KD) were applied on both groups to elucidate the role of GLP-1 in mediating cognitive function and brain glucose uptake assessed with the Morris water maze (MWM) and positron emission tomography (PET). Insulin and GLP-1 in serum and cerebral spinal fluid (CSF) were measured, and the expression of glucose uptake-related proteins including glucose transporter 1 (GLUT-1), GLUT-4, phospho-Akt substrate of 160kDa (pAS160), AS160, Rab10, Myosin-Va as well as the c-fos marker in the brain were examined. Along with augmented glucose homeostasis following DJB, central GLP-1 was correlated with the improved cognitive function and ameliorated brain glucose uptake, which was further confirmed by the enhancive role of Lira on both groups whereas the Exe-9 and Glp-1r KD were opposite. Known to activate insulin-signaling pathways, central GLP-1 contributes to improved cognitive function and brain glucose uptake after DJB.NEW & NOTEWORTHY The improvement of cognitive function following bariatric surgery has been highlighted while its mechanisms remain elusive. The brain glucose uptake of patients was improved after RYGB, and the DJB and sham surgery performed on obese and diabetic Wistar rats revealed that the elevated central GLP-1 contributes to the dramatic improvement of cognitive function, brain glucose uptake, transport, glucose sensing, and neuronal activation.
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Affiliation(s)
- Rexiati Ruze
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Qian Xu
- Department of General Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, People's Republic of China
| | - Guoqin Liu
- Department of General Surgery, Jinan Central Hospital, Shandong University, Jinan, People's Republic of China
| | - Yuekai Li
- Department of Nuclear Medicine, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Weijie Chen
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Zhiqiang Cheng
- Department of Colorectal Surgery, General Surgery, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Yacheng Xiong
- Department of General Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, People's Republic of China
| | - Shaozhuang Liu
- Department of Bariatric and Metabolic Surgery, General Surgery, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Guangyong Zhang
- Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University, Jinan, People's Republic of China
| | - Sanyuan Hu
- Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University, Jinan, People's Republic of China
| | - Zhibo Yan
- Department of Colorectal Surgery, General Surgery, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
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Ceglarek VM, Guareschi ZM, Moreira-Soares G, Ecker-Passarello RC, Balbo SL, Bonfleur ML, Grassiolli S. DUODENAL-JEJUNAL BYPASS REDUCES LIPID ACCUMULATION IN THE BROWN ADIPOSE TISSUE OF HYPOTHALAMIC OBESE RATS. ACTA ACUST UNITED AC 2020; 33:e1497. [PMID: 32667527 PMCID: PMC7357552 DOI: 10.1590/0102-672020190001e1497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/12/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Effects of duodenal-jejunal bypass surgery (DJB) on the proliferation of nuclei and the area of adipocytes in the brown adipose tissue of obese rats. Thermogenic activity in the brown adipose tissue (BAT) of obese individuals is reduced, and this condition may be modified by bariatric surgery (BS). AIM To characterize fat deposition in BAT from hypothalamic obese (HyO) rats submitted to duodenal-jejunal-bypass (DJB) surgery. METHODS For induction of hypothalamic obesity, newborn male Wistar rats were treated with subcutaneous injections of monosodium glutamate (MSG). The control (CTL) group received saline solution. At 90 days, the HyO rats were submitted to DJB or sham operation, generating the HyO-DJB and HyO-SHAM groups. At 270 days, the rats were euthanized, and the BAT was weighed and submitted to histological analysis. RESULTS Compared to BAT from CTL animals, the BAT from HyO-SHAM rats displayed increased weight, hypertrophy with greater lipid accumulation and a reduction in nucleus number. DJB effectively increased nucleus number and normalized lipid deposition in the BAT of HyO-SHAM rats, similar to that observed in CTL animals. CONCLUSION DJB surgery avoided excessive lipid deposition in the BAT of hypothalamic obese rats, suggesting that this procedure could reactivate thermogenesis in BAT, and contribute to increase energy expenditure.
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Affiliation(s)
- Vanessa Marieli Ceglarek
- Endocrine Physiology and Metabolism Laboratory, Center for Biological and Health Sciences, State University of Western Paraná, Cascavel, PR, Brazil
| | - Zoé Maria Guareschi
- Endocrine Physiology and Metabolism Laboratory, Center for Biological and Health Sciences, State University of Western Paraná, Cascavel, PR, Brazil
| | - Gabriela Moreira-Soares
- Endocrine Pancreas and Metabolism Laboratory, Department of Structural and Functional Biology, Institute of Biology, Campinas State University, Campinas, SP, Brazil
| | - Rafaela Cristiane Ecker-Passarello
- Endocrine Physiology and Metabolism Laboratory, Center for Biological and Health Sciences, State University of Western Paraná, Cascavel, PR, Brazil
| | - Sandra Lucinei Balbo
- Endocrine Physiology and Metabolism Laboratory, Center for Biological and Health Sciences, State University of Western Paraná, Cascavel, PR, Brazil
| | - Maria Lúcia Bonfleur
- Endocrine Physiology and Metabolism Laboratory, Center for Biological and Health Sciences, State University of Western Paraná, Cascavel, PR, Brazil
| | - Sabrina Grassiolli
- Endocrine Physiology and Metabolism Laboratory, Center for Biological and Health Sciences, State University of Western Paraná, Cascavel, PR, Brazil
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Mendes MC, Bonfleur ML, Ribeiro RA, Lubaczeuski C, Fêo AFJ, Vargas R, Carneiro EM, Boschero AC, Araujo ACF, Balbo SL. Duodeno-jejunal bypass restores β-cell hypersecretion and islet hypertrophy in western diet obese rats. Endocrine 2018; 60:407-414. [PMID: 29556948 DOI: 10.1007/s12020-018-1578-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/06/2018] [Indexed: 02/06/2023]
Abstract
PURPOSE Duodeno-jejunal bypass (DJB) operation improves glucose homeostasis in morbid obesity, independently of weight loss or reductions in adiposity, through mechanisms not yet fully elucidated. Herein, we evaluated the effects of DJB upon glucose homeostasis, endocrine pancreatic morphology, and β-cell responsiveness to potentiating agents of cholinergic and cAMP pathways, in western diet (WD) obese rats, at 2 months after operation. METHODS From 8 to 18 weeks of age male Wistar rats fed on a WD. After this period, a sham (WD Sham group) or DJB (WD DJB) operations were performed. At 2 months after operation glucose homeostasis was verified. RESULTS Body weight was similar between WD DJB and WD Sham rats, but WD DJB rats showed a decrease in Lee index, retroperitoneal and perigonadal fat pads. Also, WD DJB rats displayed reduced fasting glycemia and insulinemia, and increased insulin-induced Akt activation in the gastrocnemius. Islets from WD DJB rats secreted less amounts of insulin, in response to activators of the cholinergic (carbachol and phorbol 12-myristate 13-acetate) and cAMP (forskolin and 3-isobutyl-1-methyl-xantine) pathways. Islets of WD DJB rats had higher sintaxin-1 protein content than WD Sham, but without modification in muscarinic-3 receptor, protein kinase (PK)-Cα, and (PK)-Aα protein amounts. In addition, islets of WD DJB animals showed reduction in islets and β-cell masses. CONCLUSION DJB surgery improves fasting glycemia and insulin action in skeletal muscle. Better endocrine pancreatic morphofunction was associated, at least in part, with the regulation of the cholinergic and cAMP pathways, and improvements in syntaxin-1 islet protein content induced by DJB.
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Affiliation(s)
- Mariana Carla Mendes
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | - Maria Lúcia Bonfleur
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil.
| | | | - Camila Lubaczeuski
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Laboratório de Pâncreas Endócrino e Metabolismo, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ana Flavia Justino Fêo
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | - Rodrigo Vargas
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | - Everardo Magalhães Carneiro
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Laboratório de Pâncreas Endócrino e Metabolismo, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Antonio Carlos Boschero
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Laboratório de Pâncreas Endócrino e Metabolismo, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Sandra Lucinei Balbo
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
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Polce SA, Burke C, França LM, Kramer B, de Andrade Paes AM, Carrillo-Sepulveda MA. Ellagic Acid Alleviates Hepatic Oxidative Stress and Insulin Resistance in Diabetic Female Rats. Nutrients 2018; 10:nu10050531. [PMID: 29693586 PMCID: PMC5986411 DOI: 10.3390/nu10050531] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 04/18/2018] [Accepted: 04/23/2018] [Indexed: 12/11/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) affects more than 70% of patients with type 2 diabetes mellitus (T2DM) and has become one of the most common metabolic liver diseases worldwide. To date, treatments specifically targeting NAFLD do not exist. Oxidative stress and insulin resistance have been implicated in the pathogenesis of NAFLD in diabetes. Accordingly, the goal of this present study was to determine whether Ellagic acid (EA), a natural antioxidant polyphenol found in berries and nuts, mitigates hepatic oxidative stress and insulin resistance in T2DM rats, and thus alleviates NAFLD. Using adult female Goto Kakizaki (GK) rats, a non-obese and spontaneous model of T2DM, we found that EA treatment significantly lowered fasting blood glucose and reduced insulin resistance, as shown by a 21.8% reduction in the homeostasis model assessment index of insulin resistance (HOMA-IR), while triglyceride and total cholesterol levels remained unchanged. Increased hepatic lipid accumulation and oxidative stress present in diabetic GK rats was markedly reduced with EA treatment. This effect was associated with a downregulation of the NADPH oxidase subunit, p47-phox, and overexpression of NF-E2-related factor-2 (NRF2). Moreover, EA was able to decrease the hepatic expression of hypoxia-inducible factor (HIF-α), a transcription factor linked to hypoxia and hepatic steatosis. We further showed that EA treatment activated an insulin signaling pathway in the liver, as evidenced by increased levels of phosphorylated Akt (Ser 473). In conclusion, our results demonstrate that EA diminishes blood glucose levels and potently suppress NAFLD in diabetic rats via mechanisms that involve reductions in p47-phox and HIF-α, upregulation of NRF2 and enhancement of the Akt signaling pathway in the liver. Together, these results reveal that EA improves hepatic insulin sensitivity and lipid metabolism as a result of its antioxidant effects. This implies an anti-diabetic effect of EA with beneficial effects for the treatment of hepatic complications in T2DM.
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Affiliation(s)
- Simran Alexandria Polce
- Department of Life Sciences, College of Arts and Sciences, New York Institute of Technology, Old Westbury, NY 11568, USA.
| | - Cameron Burke
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA.
| | - Lucas Martins França
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhao, Sao Luis, MA 65080-805, Brazil.
| | - Benjamin Kramer
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA.
| | - Antonio Marcus de Andrade Paes
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhao, Sao Luis, MA 65080-805, Brazil.
| | - Maria Alicia Carrillo-Sepulveda
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA.
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Soares GM, Cantelli KR, Balbo SL, Ribeiro RA, Alegre-Maller ACP, Barbosa-Sampaio HC, Boschero AC, Araújo ACF, Bonfleur ML. Liver steatosis in hypothalamic obese rats improves after duodeno-jejunal bypass by reduction in de novo lipogenesis pathway. Life Sci 2017; 188:68-75. [PMID: 28866102 DOI: 10.1016/j.lfs.2017.08.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 02/07/2023]
Abstract
AIMS Hypothalamic obesity is a severe condition without any effective therapy. Bariatric operations appear as an alternative treatment, but the effects of this procedure are controversial. We, herein, investigated the effects of duodeno-jejunal bypass (DJB) surgery upon the lipid profile and expression of genes and proteins, involved in the regulation of hepatic lipid metabolism, in hypothalamic obese (HyO) rats. METHODS During the first 5days of life, male newborn Wistar rats received subcutaneous injections of monosodium glutamate [4g/kg body weight, HyO group] or saline (control, CTL group). At 90days of life, HyO rats were randomly submitted to DJB (HyO DJB) or Sham-operations (HyO Sham group). Six months after DJB, adiposity, hepatic steatosis and lipid metabolism were verified. KEY FINDINGS HyO Sham rats were obese, hyperinsulinemic, insulin resistant and dyslipidemic. These rats had higher liver contents of trygliceride (TG) and presented disorganization of the hepatocyte structures, in association with higher hepatic contents of acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN), and stearoyl-CoA desaturase-1 mRNAs and protein. DJB surgery normalized insulinemia, insulin resistance, and dyslipidemia in HyO rats. TG content in the liver and the hepatic microscopic structures were also normalized in HyO DJB rats, while the expressions of ACC and FASN proteins were decreased in the liver of these rodents. SIGNIFICANCE The DJB-induced amelioration in hepatic steatosis manifested as a late effect in HyO rats, and was partly associated with a downregulation in hepatic de novo lipogenesis processes, indicating that DJB protects against liver steatosis in hypothalamic obesity.
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Affiliation(s)
- Gabriela Moreira Soares
- Laboratório de Fisiologia Endócrina e Metabolismo (LAFEM), Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | - Kathia Regina Cantelli
- Laboratório de Fisiologia Endócrina e Metabolismo (LAFEM), Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | - Sandra Lucinei Balbo
- Laboratório de Fisiologia Endócrina e Metabolismo (LAFEM), Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | | | - Ana Claudia Paiva Alegre-Maller
- Laboratório de Fisiologia Endócrina e Metabolismo (LAFEM), Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil
| | - Helena Cristina Barbosa-Sampaio
- Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Antonio Carlos Boschero
- Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Maria Lúcia Bonfleur
- Laboratório de Fisiologia Endócrina e Metabolismo (LAFEM), Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná (UNIOESTE), Cascavel, PR, Brazil.
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Cantelli KR, Soares GM, Ribeiro RA, Balbo SL, Lubaczeuski C, Boschero AC, Araújo ACF, Bonfleur ML. Duodenal-jejunal bypass normalizes pancreatic islet proliferation rate and function but not hepatic steatosis in hypothalamic obese rats. ACTA ACUST UNITED AC 2017; 50:e5858. [PMID: 28380195 PMCID: PMC5423738 DOI: 10.1590/1414-431x20175858] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/06/2017] [Indexed: 12/21/2022]
Abstract
Modifications in life-style and/or pharmacotherapies contribute to weight loss and ameliorate the metabolic profile of diet-induced obese humans and rodents. Since these strategies fail to treat hypothalamic obesity, we have assessed the possible mechanisms by which duodenal-jejunal bypass (DJB) surgery regulates hepatic lipid metabolism and the morphophysiology of pancreatic islets, in hypothalamic obese (HyO) rats. During the first 5 days of life, male Wistar rats received subcutaneous injections of monosodium glutamate (4 g/kg body weight, HyO group), or saline (CTL). At 90 days of age, HyO rats were randomly subjected to DJB (HyO DJB group) or sham surgery (HyO Sham group). HyO Sham rats were morbidly obese, insulin resistant, hypertriglyceridemic and displayed higher serum concentrations of non-esterified fatty acids (NEFA) and hepatic triglyceride (TG). These effects were associated with higher expressions of the lipogenic genes and fatty acid synthase (FASN) protein content in the liver. Furthermore, hepatic genes involved in β-oxidation and TG export were down-regulated in HyO rats. In addition, these rats exhibited hyperinsulinemia, β-cell hypersecretion, a higher percentage of islets and β-cell area/pancreas section, and enhanced nuclear content of Ki67 protein in islet-cells. At 2 months after DJB surgery, serum concentrations of TG and NEFA, but not hepatic TG accumulation and gene and protein expressions, were normalized in HyO rats. Insulin release and Ki67 positive cells were also normalized in HyO DJB islets. In conclusion, DJB decreased islet-cell proliferation, normalized insulinemia, and ameliorated insulin sensitivity and plasma lipid profile, independently of changes in hepatic metabolism.
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Affiliation(s)
- K R Cantelli
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
| | - G M Soares
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
| | - R A Ribeiro
- Universidade Federal do Rio de Janeiro, Macaé, RJ, Brasil
| | - S L Balbo
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
| | - C Lubaczeuski
- Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de Biologia Estrutural e Funcional Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - A C Boschero
- Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de Biologia Estrutural e Funcional Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - A C F Araújo
- Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
| | - M L Bonfleur
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
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Oral Metformin Treatment Counteracts Adipoinsular Axis Dysfunction in Hypothalamic Obese Rats. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2015; 2015:284042. [PMID: 27347514 PMCID: PMC4897058 DOI: 10.1155/2015/284042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 11/17/2022]
Abstract
Rats neonatally treated with monosodium L-glutamate (MSG) are deeply dysfunctional in adulthood. We explored the effect of an oral low dose of metformin treatment in male MSG rats on adipoinsular axis and visceral adipose tissue (VAT) dysfunctions, in both basal (nonfasting) and endotoxemia conditions. MSG rats, treated or not treated with metformin (30 days prior to experimentation), and control litter-mates (CTR) were studied at 90 days of age. Peripheral concentrations of glucose, lipids, and hormones were determined in basal and post-lipopolysaccharide (LPS) treatment conditions. Food intake and body weight (BW) were recorded and VAT mass and leptin mRNA levels were evaluated. Data indicated that MSG rats were lighter and displayed hypercorticosteronemia, hypophagia, adipoinsular axis hyperactivity, and enhanced VAT mass associated with an increased leptin gene expression. Interestingly, metformin-treated MSG rats corrected BW catch-up and counteracted VAT (mass and leptin mRNA level) and adipoinsular axis (basal and post-LPS) dysfunctions. Thus metformin treatment in MSG rats is able to correct several VAT and metabolic-endocrine dysfunctions. Our study suggests that a low-dose metformintherapy is effective to correct, at least in part, adipoinsular axis dysfunction in hypertrophic obese phenotypes, such as that of the human Cushing syndrome.
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