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Shoier NO, Ghareib SA, Kothayer H, Alsemeh AE, El-Sayed SS. Vitamin D3 mitigates myopathy and metabolic dysfunction in rats with metabolic syndrome: the potential role of dipeptidyl peptidase-4. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03439-3. [PMID: 39356321 DOI: 10.1007/s00210-024-03439-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Accepted: 09/06/2024] [Indexed: 10/03/2024]
Abstract
Metabolic syndrome is associated with vitamin D3 deficiency. This work aims to examine the efficacy of vitamin D3 in inhibiting MetS-induced myopathy and to determine whether the beneficial effects of vitamin D3 are mediated by the inhibition of dipeptidyl peptidase-4 (DPP-4). An in silico study investigated the potential effectiveness of vitamin D3 on the inhibition of the DPP-4 enzyme. An in vitro assay of the DPP-4 inhibitory effect of vitamin D3 was performed. In vivo and over 12 weeks, both diet (with 3% salt) and drinking water (with 10% fructose) were utilized to induce MetS. In the seventh week, rats received either vitamin D3, vildagliptin, a combination of both, or vehicles. Serum lipids, adipokines, glycemic indices, and glucagon-like peptide-1 (GLP-1), muscular glucose transporter type-4 (GLUT-4) content, DPP-4, adenosine monophosphate kinase (AMPK) activities, and Sudan Black B-stained lipids were assessed. Muscular reactive oxygen species (ROS), caspase-3, and desmin immunostaining were used to determine myopathy. MetS-induced metabolic dysfunction was ameliorated by vitamin D3, which also reduced intramuscular glycogen and lipid accumulation. This is demonstrated by the attenuation of MetS-induced myopathy by vitamin D3, decreased oxidative stress, increased desmin immuno-expression, and caspase-3 activity. Our in silico data demonstrated that vitamin D3 is capable of inhibiting DPP-4, which is further supported by biochemical findings. Vitamin D3 increased serum GLP-1, muscular AMPK activity, and GLUT-4 content, whereas the levels of muscular ROS were decreased in MetS. Vildagliptin and its combination with vitamin D3 yielded comparable results. It is suggested that the DPP-4 inhibitory potential of vitamin D3 is responsible for the amelioration of MetS-induced metabolic changes and myopathy.
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Affiliation(s)
- Nourhan O Shoier
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt
| | - Salah A Ghareib
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt
| | - Hend Kothayer
- Medicinal Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Amira Ebrahim Alsemeh
- Human Anatomy and Embryology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Shaimaa S El-Sayed
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt.
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Johnson RJ, Lanaspa MA, Sanchez-Lozada LG, Tolan D, Nakagawa T, Ishimoto T, Andres-Hernando A, Rodriguez-Iturbe B, Stenvinkel P. The fructose survival hypothesis for obesity. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220230. [PMID: 37482773 PMCID: PMC10363705 DOI: 10.1098/rstb.2022.0230] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 05/04/2023] [Indexed: 07/25/2023] Open
Abstract
The fructose survival hypothesis proposes that obesity and metabolic disorders may have developed from over-stimulation of an evolutionary-based biologic response (survival switch) that aims to protect animals in advance of crisis. The response is characterized by hunger, thirst, foraging, weight gain, fat accumulation, insulin resistance, systemic inflammation and increased blood pressure. The process is initiated by the ingestion of fructose or by stimulating endogenous fructose production via the polyol pathway. Unlike other nutrients, fructose reduces the active energy (adenosine triphosphate) in the cell, while blocking its regeneration from fat stores. This is mediated by intracellular uric acid, mitochondrial oxidative stress, the inhibition of AMP kinase and stimulation of vasopressin. Mitochondrial oxidative phosphorylation is suppressed, and glycolysis stimulated. While this response is aimed to be modest and short-lived, the response in humans is exaggerated due to gain of 'thrifty genes' coupled with a western diet rich in foods that contain or generate fructose. We propose excessive fructose metabolism not only explains obesity but the epidemics of diabetes, hypertension, non-alcoholic fatty liver disease, obesity-associated cancers, vascular and Alzheimer's dementia, and even ageing. Moreover, the hypothesis unites current hypotheses on obesity. Reducing activation and/or blocking this pathway and stimulating mitochondrial regeneration may benefit health-span. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.
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Affiliation(s)
- Richard J. Johnson
- Department of Medicine, University of Colorado Anschutz Medical Center, Aurora, CO 80016, USA
| | - Miguel A. Lanaspa
- Department of Medicine, University of Colorado Anschutz Medical Center, Aurora, CO 80016, USA
| | - L. Gabriela Sanchez-Lozada
- Department of Cardio-Renal Physiopathology, Instituto Nacional de Cardiología ‘Ignacio Chavez’, Mexico City 14080, Mexico
| | - Dean Tolan
- Biology Department, Boston University, Boston, MA 02215, USA
| | - Takahiko Nakagawa
- Department of Nephrology, Rakuwakai-Otowa Hospital, Kyoto 607-8062, Japan
| | - Takuji Ishimoto
- Department of Nephrology and Rheumatology, Aichi Medical University, Aichi 480-1103, Japan
| | - Ana Andres-Hernando
- Department of Medicine, University of Colorado Anschutz Medical Center, Aurora, CO 80016, USA
| | - Bernardo Rodriguez-Iturbe
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición ‘Salvador Zubirán’, Mexico City 14080, Mexico
| | - Peter Stenvinkel
- Department of Renal Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
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Johnson RJ, Tolan DR, Bredesen D, Nagel M, Sánchez-Lozada LG, Fini M, Burtis S, Lanaspa MA, Perlmutter D. Could Alzheimer's disease be a maladaptation of an evolutionary survival pathway mediated by intracerebral fructose and uric acid metabolism? Am J Clin Nutr 2023; 117:455-466. [PMID: 36774227 PMCID: PMC10196606 DOI: 10.1016/j.ajcnut.2023.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/21/2022] [Accepted: 01/04/2023] [Indexed: 01/12/2023] Open
Abstract
An important aspect of survival is to assure enough food, water, and oxygen. Here, we describe a recently discovered response that favors survival in times of scarcity, and it is initiated by either ingestion or production of fructose. Unlike glucose, which is a source for immediate energy needs, fructose metabolism results in an orchestrated response to encourage food and water intake, reduce resting metabolism, stimulate fat and glycogen accumulation, and induce insulin resistance as a means to reduce metabolism and preserve glucose supply for the brain. How this survival mechanism affects brain metabolism, which in a resting human amounts to 20% of the overall energy demand, is only beginning to be understood. Here, we review and extend a previous hypothesis that this survival mechanism has a major role in the development of Alzheimer's disease and may account for many of the early features, including cerebral glucose hypometabolism, mitochondrial dysfunction, and neuroinflammation. We propose that the pathway can be engaged in multiple ways, including diets high in sugar, high glycemic carbohydrates, and salt. In summary, we propose that Alzheimer's disease may be the consequence of a maladaptation to an evolutionary-based survival pathway and what had served to enhance survival acutely becomes injurious when engaged for extensive periods. Although more studies are needed on the role of fructose metabolism and its metabolite, uric acid, in Alzheimer's disease, we suggest that both dietary and pharmacologic trials to reduce fructose exposure or block fructose metabolism should be performed to determine whether there is potential benefit in the prevention, management, or treatment of this disease.
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Affiliation(s)
- Richard J Johnson
- Department of Medicine, Rocky Mountain VA Medical Center, Aurora, CO, USA; Department of Medicine, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
| | - Dean R Tolan
- Biology Department, Boston University, Boston, MA, USA
| | - Dale Bredesen
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Maria Nagel
- Department of Neurology, University of Colorado Anschutz Medical Center, Aurora, CO, USA
| | - Laura G Sánchez-Lozada
- Department of Cardio-Renal Physiopathology, National Institute of Cardiology Ignacio Chávez, Mexico City, Mexico
| | - Mehdi Fini
- Department of Medicine, University of Colorado Anschutz Medical Center, Aurora, CO, USA
| | | | - Miguel A Lanaspa
- Department of Medicine, University of Colorado Anschutz Medical Center, Aurora, CO, USA
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Ahmed S, Sulaiman SA, Baig AA, Ibrahim M, Liaqat S, Fatima S, Jabeen S, Shamim N, Othman NH. Honey as a Potential Natural Antioxidant Medicine: An Insight into Its Molecular Mechanisms of Action. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8367846. [PMID: 29492183 PMCID: PMC5822819 DOI: 10.1155/2018/8367846] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/19/2017] [Indexed: 12/13/2022]
Abstract
Honey clasps several medicinal and health effects as a natural food supplement. It has been established as a potential therapeutic antioxidant agent for various biodiverse ailments. Data report that it exhibits strong wound healing, antibacterial, anti-inflammatory, antifungal, antiviral, and antidiabetic effects. It also retains immunomodulatory, estrogenic regulatory, antimutagenic, anticancer, and numerous other vigor effects. Data also show that honey, as a conventional therapy, might be a novel antioxidant to abate many of the diseases directly or indirectly associated with oxidative stress. In this review, these wholesome effects have been thoroughly reviewed to underscore the mode of action of honey exploring various possible mechanisms. Evidence-based research intends that honey acts through a modulatory road of multiple signaling pathways and molecular targets. This road contemplates through various pathways such as induction of caspases in apoptosis; stimulation of TNF-α, IL-1β, IFN-γ, IFNGR1, and p53; inhibition of cell proliferation and cell cycle arrest; inhibition of lipoprotein oxidation, IL-1, IL-10, COX-2, and LOXs; and modulation of other diverse targets. The review highlights the research done as well as the apertures to be investigated. The literature suggests that honey administered alone or as adjuvant therapy might be a potential natural antioxidant medicinal agent warranting further experimental and clinical research.
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Affiliation(s)
- Sarfraz Ahmed
- Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, 16150 Kelantan, Malaysia
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Siti Amrah Sulaiman
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, 16150 Kelantan, Malaysia
| | - Atif Amin Baig
- Faculty of Medicine, Universiti Sultan Zainal Abidin, Darul Iman, Kuala Terengganu, 20400 Terengganu, Malaysia
| | - Muhammad Ibrahim
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Sana Liaqat
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Saira Fatima
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Sadia Jabeen
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Nighat Shamim
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Nor Hayati Othman
- Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, 16150 Kelantan, Malaysia
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Jemil I, Nasri R, Abdelhedi O, Aristoy MC, Salem RBSB, Kallel C, Marrekchi R, Jamoussi K, ElFeki A, Hajji M, Toldrá F, Nasri M. Beneficial effects of fermented sardinelle protein hydrolysates on hypercaloric diet induced hyperglycemia, oxidative stress and deterioration of kidney function in wistar rats. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2017; 54:313-325. [PMID: 28242930 PMCID: PMC5306024 DOI: 10.1007/s13197-016-2464-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 12/14/2016] [Accepted: 12/23/2016] [Indexed: 02/07/2023]
Abstract
This study investigated the potential effects of fermented sardinelle protein hydrolysates (FSPHs) obtained by two proteolytic bacteria, Bacillus subtilis A26 (FSPH-A26) and Bacillus amyloliquefaciens An6 (FSPH-An6), on hypercaloric diet (HCD) induced hyperglycemia and oxidative stress in rats. Effects of FSPHs on blood glucose level, glucose tolerance, α-amylase activity and hepatic glycogen content were investigated, as well as their effect on the oxidative stress state. Biochemical findings revealed that, while undigested sardinelle proteins did not exhibit hypoglycemic activity, oral administration of FSPHs to HCD-fed rats reduced significantly α-amylase activity as well as glycemia and hepatic glycogen levels. Further, the treatment with FSPHs improved the redox status by decreasing the levels of lipid peroxidation products and increasing the activities of the antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) and the level of glutathione in the liver and kidneys, as compared to those of HCD-fed rats. FSPHs were also found to exert significant protective effects on liver and kidney functions, evidenced by a marked decrease in alkaline phosphatase activity and a modulation of creatinine and uric acid contents. These results indicated the beneficial effect of FSPHs on the prevention from hyperglycemia and oxidative stress.
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Affiliation(s)
- Ines Jemil
- Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P. O. Box 1173, 3038 Sfax, Tunisia
| | - Rim Nasri
- Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P. O. Box 1173, 3038 Sfax, Tunisia
| | - Ola Abdelhedi
- Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P. O. Box 1173, 3038 Sfax, Tunisia
| | - Maria-Concepción Aristoy
- Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Avenue Agustín Escardino 7, Paterna, 46980 Valencia, Spain
| | - Rabeb Ben Slama-Ben Salem
- Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P. O. Box 1173, 3038 Sfax, Tunisia
| | - Choumous Kallel
- Laboratory of Hematology, Habib Bourguiba Hospital, 3029 Sfax, Tunisia
| | - Rim Marrekchi
- Laboratory of Biochemistry, CHU Hedi Chaker, 3029 Sfax, Tunisia
| | - Kamel Jamoussi
- Laboratory of Biochemistry, CHU Hedi Chaker, 3029 Sfax, Tunisia
| | - Abdelfattah ElFeki
- Laboratory of Animal Ecophysiology, Faculty of Sciences of Sfax (FSS), University of Sfax, P. O. Box 95, 3052 Sfax, Tunisia
| | - Mohamed Hajji
- Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P. O. Box 1173, 3038 Sfax, Tunisia
| | - Fidel Toldrá
- Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Avenue Agustín Escardino 7, Paterna, 46980 Valencia, Spain
| | - Moncef Nasri
- Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P. O. Box 1173, 3038 Sfax, Tunisia
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Nasri R, Abdelhedi O, Jemil I, Daoued I, Hamden K, Kallel C, Elfeki A, Lamri-Senhadji M, Boualga A, Nasri M, Karra-Châabouni M. Ameliorating effects of goby fish protein hydrolysates on high-fat-high-fructose diet-induced hyperglycemia, oxidative stress and deterioration of kidney function in rats. Chem Biol Interact 2015; 242:71-80. [DOI: 10.1016/j.cbi.2015.08.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 08/03/2015] [Accepted: 08/07/2015] [Indexed: 12/26/2022]
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Rovenko BM, Perkhulyn NV, Gospodaryov DV, Sanz A, Lushchak OV, Lushchak VI. High consumption of fructose rather than glucose promotes a diet-induced obese phenotype in Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2014; 180:75-85. [PMID: 25461489 DOI: 10.1016/j.cbpa.2014.11.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/04/2014] [Accepted: 11/07/2014] [Indexed: 12/31/2022]
Abstract
During the last 20 years, there has been a considerable scientific debate about the possible mechanisms of induction of metabolic disorders by reducing monosaccharides such as glucose or fructose. In this study, we report the metabolic rearrangement in response to consumption of these monosaccharides at concentrations ranging from 0.25% to 20% in a Drosophila model. Flies raised on high-glucose diet displayed delay in pupation and increased developmental mortality compared with fructose consumers. Both monosaccharides at high concentrations promoted an obese-like phenotype indicated by increased fly body mass, levels of uric acid, and circulating and stored carbohydrates and lipids; and decreased percentage of water in the body. However, flies raised on fructose showed lower levels of circulating glucose and higher concentrations of stored carbohydrates, lipids, and uric acid. The preferential induction of obesity caused by fructose in Drosophila was associated with increased food consumption and reduced mRNA levels of DILP2 and DILP5 in the brain of adult flies. Our data show that glucose and fructose differently affect carbohydrate and lipid metabolism in Drosophila in part by modulation of insulin/insulin-like growth factor signaling. Some reported similarities with effects observed in mammals make Drosophila as a useful model to study carbohydrate influence on metabolism and development of metabolic disorders.
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Affiliation(s)
- Bohdana M Rovenko
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, 76025, Ukraine
| | - Natalia V Perkhulyn
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, 76025, Ukraine
| | - Dmytro V Gospodaryov
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, 76025, Ukraine
| | - Alberto Sanz
- Institute for Cell and Molecular Biosciences and Newcastle Institute for Ageing, Newcastle University, Newcastle-Upon-Tyne, UK, NE4 5PL
| | - Oleh V Lushchak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, 76025, Ukraine.
| | - Volodymyr I Lushchak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, 76025, Ukraine.
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Cambri LT, Ribeiro C, Botezelli JD, Ghezzi AC, Mello MAR. Muscle glycogen metabolism changes in rats fed early postnatal a fructose-rich diet after maternal protein malnutrition: effects of acute physical exercise at the maximal lactate steady-state intensity. Diabetol Metab Syndr 2014; 6:118. [PMID: 25400700 PMCID: PMC4232698 DOI: 10.1186/1758-5996-6-118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 10/03/2014] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The objective was to evaluate the muscle glucose metabolism in rats fed a fructose-rich diet after fetal protein malnutrition, at rest and after acute physical exercise at maximal lactate steady-state intensity. METHODS The male offspring born of mothers fed on a balanced or low-protein diet were split in four groups until 60 days: Balanced (B): balanced diet during the whole period; Balanced/Fructose (BF): balanced diet in utero and fructose-rich diet after birth; Low protein/Balanced (LB): low-protein diet in utero and balanced diet after birth; Low protein/Fructose (LF): low protein diet in utero and fructose-rich diet after birth. RESULTS Acute physical exercise reduced the muscle glycogen concentrations in all groups, although the LF group showed higher concentrations at rest. There was no difference among the groups in the glucose uptake and oxidation rates in the isolated soleus muscle neither at rest nor after acute exercise. However, glycogen synthesis was higher in the LF muscle than in the others at rest. Acute physical exercise increased glycogen synthesis in all groups, and the LF group showed the highest values. CONCLUSION The fructose-rich diet administered in rats after fetal protein malnutrition alters muscle glycogen concentrations and glycogen synthesis in the rest and after acute exercise at maximal lactate steady-state intensity.
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Affiliation(s)
- Lucieli T Cambri
- />São Paulo State University (UNESP), Rio Claro, SP Brazil
- />Federal University of Mato Grosso (UFMT), Cuiabá, MT, Brazil. Physical Education Department, UFMT, Av. Fernando Corrêa da Costa, 2367 - Boa Esperança, Cuiabá, Zip-Code:- 78060-900 MT Brazil
| | - Carla Ribeiro
- />São Paulo State University (UNESP), Rio Claro, SP Brazil
| | | | - Ana C Ghezzi
- />São Paulo State University (UNESP), Rio Claro, SP Brazil
| | - Maria AR Mello
- />São Paulo State University (UNESP), Rio Claro, SP Brazil
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Al-Waili N, Salom K, Al-Ghamdi A, Ansari MJ, Al-Waili A, Al-Waili T. Honey and cardiovascular risk factors, in normal individuals and in patients with diabetes mellitus or dyslipidemia. J Med Food 2014; 16:1063-78. [PMID: 24328699 DOI: 10.1089/jmf.2012.0285] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Diabetes mellitus, hypercholesteremia, hypertension (HTN), and obesity are well-known risk factors for cardiovascular diseases (CVD). Various medications are currently in use for management of these comorbidities. Undesirable side effects are unavoidable and the ultimate and ideal goal is hardly achieved. Honey and other bee products are widely used in traditional medicine for management of many diseases. Others and the authors have found potent biological activities of these products. Honey is now reintroduced in modern medicine as part of wound and burn management. Honey has antioxidant, anti-inflammatory, and antimicrobial activities. More studies are exploring other aspects of honey activity such as its effect on blood sugar, body weight, lipid profile, C-reactive protein, nitric oxide, proinflammatory prostaglandins, and homocysteine. Growing evidence and scientific data support the use of honey in patients with diabetes, HTN, dyslipidemia, obesity, and CVD. This review discusses clinical and preclinical studies on potential influence of honey on diabetes mellitus and cardiovascular risk factors, and emphasizes the importance of conducting more clinical and controlled studies.
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Erejuwa OO, Sulaiman SA, Wahab MSA. Fructose might contribute to the hypoglycemic effect of honey. Molecules 2012; 17:1900-15. [PMID: 22337138 PMCID: PMC6268125 DOI: 10.3390/molecules17021900] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 02/09/2012] [Accepted: 02/09/2012] [Indexed: 12/20/2022] Open
Abstract
Honey is a natural substance with many medicinal properties, including antibacterial, hepatoprotective, hypoglycemic, antioxidant and antihypertensive effects. It reduces hyperglycemia in diabetic rats and humans. However, the mechanism(s) of its hypoglycemic effect remain(s) unknown. Honey comprises many constituents, making it difficult to ascertain which component(s) contribute(s) to its hypoglycemic effect. Nevertheless, available evidence indicates that honey consists of predominantly fructose and glucose. The objective of this review is to summarize findings which indicate that fructose exerts a hypoglycemic effect. The data show that glucose and fructose exert a synergistic effect in the gastrointestinal tract and pancreas. This synergistic effect might enhance intestinal fructose absorption and/or stimulate insulin secretion. The results indicate that fructose enhances hepatic glucose uptake and glycogen synthesis and storage via activation of hepatic glucokinase and glycogen synthase, respectively. The data also demonstrate the beneficial effects of fructose on glycemic control, glucose- and appetite-regulating hormones, body weight, food intake, oxidation of carbohydrate and energy expenditure. In view of the similarities of these effects of fructose with those of honey, the evidence may support the role of fructose in honey in mediating the hypoglycemic effect of honey.
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Affiliation(s)
- Omotayo O Erejuwa
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
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Décombaz J, Jentjens R, Ith M, Scheurer E, Buehler T, Jeukendrup A, Boesch C. Fructose and galactose enhance postexercise human liver glycogen synthesis. Med Sci Sports Exerc 2012; 43:1964-71. [PMID: 21407126 DOI: 10.1249/mss.0b013e318218ca5a] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Both liver and muscle glycogen stores play a fundamental role in exercise and fatigue, but the effect of different CHO sources on liver glycogen synthesis in humans is unclear. The aim was to compare the effect of maltodextrin (MD) drinks containing galactose, fructose, or glucose on postexercise liver glycogen synthesis. METHODS In this double-blind, triple crossover, randomized clinical trial, 10 well-trained male cyclists performed three experimental exercise sessions separated by at least 1 wk. After performing a standard exercise protocol to exhaustion, subjects ingested one of three 15% CHO solutions, namely, FRU (MD + fructose, 2:1), GAL (MD + galactose, 2:1), or GLU (MD + glucose, 2:1), each providing 69 g CHO·h(-1) during 6.5 h of recovery. Liver glycogen changes were followed using (13)C magnetic resonance spectroscopy. RESULTS Liver glycogen concentration increased at faster rates with FRU (24 ± 2 mmol·L(-1)·h(-1), P < 0.001) and with GAL (28 ± 3 mmol·L(-1)·h(-1), P < 0.001) than with GLU (13 ± 2 mmol·L(-1)·h(-1)). Liver volumes increased (P < 0.001) with FRU (9% ± 2%) and with GAL (10% ± 2%) but not with GLU (2% ± 1%, NS). Net glycogen synthesis appeared linear and was faster with FRU (8.1 ± 0.6 g·h(-1), P < 0.001) and with GAL (8.6 ± 0.9 g·h(-1), P < 0.001) than with GLU (3.7 ± 0.5 g·h(-1)). CONCLUSIONS When ingested at a rate designed to saturate intestinal CHO transport systems, MD drinks with added fructose or galactose were twice as effective as MD + glucose in restoring liver glycogen during short-term postexercise recovery.
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Bruce SJ, Breton I, Decombaz J, Boesch C, Scheurer E, Montoliu I, Rezzi S, Kochhar S, Guy PA. A plasma global metabolic profiling approach applied to an exercise study monitoring the effects of glucose, galactose and fructose drinks during post-exercise recovery. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:3015-23. [DOI: 10.1016/j.jchromb.2010.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 09/01/2010] [Accepted: 09/02/2010] [Indexed: 01/23/2023]
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13
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Yadav H, Jain S, Yadav M, Sinha PR, Prasad GBKS, Marotta F. Epigenomic derangement of hepatic glucose metabolism by feeding of high fructose diet and its prevention by Rosiglitazone in rats. Dig Liver Dis 2009; 41:500-8. [PMID: 19196556 DOI: 10.1016/j.dld.2008.11.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 11/11/2008] [Accepted: 11/17/2008] [Indexed: 02/07/2023]
Abstract
BACKGROUND The high consumption of fructose leads to the increasing incidence of insulin resistance by several unknown mechanisms. Hepatic glucose metabolism may also be an important target of fructose-induced-metabolic alterations. AIM The aim of present study was to investigate alterations in hepatic glycogenolysis, glycogenesis and gluconeogenic fluxes by feeding of 21% high fructose diet and the effects of Rosiglitazone treatment to prevent these derangements in rats. METHODS Rats were maintained on normal chow and high fructose diet with or without Rosiglitazone for 8 weeks and various biochemical and gene expression measures were estimated. RESULTS The feeding of high fructose diet impaired glucose, insulin and pyruvate tolerance tests and increased blood HbA(1c), insulin, triglyceride, free fatty acids and homeostasis model assessment after 8 weeks. In addition, high fructose diet feeding increased expression of phosphoenol-pyruvatecorboxykinase, glucose-6-phosphatase, sterol regulatory element binding proteins-1 and fatty acid synthase through enhanced expression of fork-head receptor, peroxisome proliferator activated receptor-gamma-co-activator 1 and cAMP reactive element binding protein. The treatment with Rosiglitazone inhibited all these derangements, i.e. hepato-lipogenic and gluconeogenic effects of high fructose diet feeding in rats. CONCLUSIONS Together these findings suggest that high fructose diet induced hepatic gluconeogenic and lipogenic rate, and increased circulating triglycerides and free fatty acids, which may be the major risk factors for glucose intolerance, hyperglycemia and insulin resistance in rats. In such situations high fructose flux also induces transcriptional cascade of gluconeogenic enzymes through the modulation of various associated transcriptional factors.
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Affiliation(s)
- H Yadav
- Animal Biochemistry Division, National Dairy Research Institute, Karnal, Haryana, India.
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Radziuk J, Pye S. Hepatic glucose uptake, gluconeogenesis and the regulation of glycogen synthesis. Diabetes Metab Res Rev 2001; 17:250-72. [PMID: 11544610 DOI: 10.1002/dmrr.217] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hepatic glycogen is replenished during the absorptive period postprandially. This repletion is prompted partly by an increased hepatic uptake of glucose by the liver, partly by metabolite and hormonal signals in the portal vein, and partly by an increased gluconeogenic flux to glycogen (glyconeogenesis). There is some evidence that the direct formation of glycogen from glucose and that formed by gluconeogenic pathways is linked. This includes: (i) the inhibition of all glycogen synthesis, in vivo, when gluconeogenic flux is blocked by inhibitors; (ii) a dual relationship between glucose concentrations, lactate uptake by the liver and glycogen synthesis (by both pathways) which indicates that glucose sets the maximal rates of glycogen synthesis while lactate uptake determines the actual flux rate to glycogen; (iii) the decrease of both gluconeogenesis and glycogen synthesis by the biguanide, metformin; and (iv) correlations between increased gluconeogenesis and liver glycogen in obese patients and animal models. The degree to which the liver extracts portal glucose is not entirely agreed upon although a preponderance of evidence points to about a 5% extraction rate, following meals, which is dependent on a stimulation of glucokinase. This enzyme may be linked to the expression of other enzymes in the gluconeogenic pathway. Perivenous cells in the liver may induce additional gluconeogenesis in the periportal cells by increasing glycolytically produced lactate. A number of potential mechanisms therefore exist which could link glycogen synthesis from glucose and gluconeogenic substrate.
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Affiliation(s)
- J Radziuk
- Diabetes and Metabolism Research Unit, Ottawa Hospital, 1053 Carling Avenue, Ottawa, Ontario, Canada K1Y 4E9.
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Bruynseels K, Bergans N, Gillis N, van Dorpen F, Van Hecke P, Stalmans W, Vanstapel F. On the inhibition of hepatic glycogenolysis by fructose. A 31P-NMR study in perfused rat liver using the fructose analogue 2,5-anhydro-D-mannitol. NMR IN BIOMEDICINE 1999; 12:145-156. [PMID: 10414949 DOI: 10.1002/(sici)1099-1492(199905)12:3<145::aid-nbm559>3.0.co;2-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Inhibition of hormone-stimulated hepatic glycogenolysis by fructose (Fru) has been attributed to accumulation of the competitive inhibitor Fru1P and/or to the associated depletion of the substrate phosphate (Pi). To evaluate the relative importance of either factor, we used the Fru analogue 2,5-anhydro-D-mannitol (aHMol). This analogue is avidly phosphorylated, traps Pi, and inhibits hormone-stimulated glycogenolysis, but it is not a gluconeogenic substrate, and hence does not confound glycogenolytic glucose production. Livers were continuously perfused with dibutyryl-cAMP (100 microM) to clamp phosphorylase in its fully activated a form. We administered aHMol (3.8 mM), and studied changes in glycogenolysis (glucose, lactate and pyruvate output) and in cytosolic Pi and phosphomonoester (PME), using in situ 31P-NMR spectroscopy (n = 4). Lobes of seven livers perfused outside the magnet were extracted for evaluation, by high-resolution 31P-NMR, of the evolution of aHMol1P and of aHMol(1,6)P2. After addition of aHMol, both glycogenolysis and the NMR Pi signal dropped precipitously, while the PME signal rose continuously and was almost entirely composed of aHMol1P. Inhibition of glycogenolysis in excess of the drop in Pi could be explained by continuing accumulation of aHMol1P. A subsequent block of mitochondrial ATP synthesis by KCN (1 mM) caused a rapid increase of Pi. Despite recovery of Pi to values exceeding control levels, glycogenolysis only recovered partially, attesting to the Pi-dependence of glycogenolysis, but also to inhibition by aHMol phosphorylation products. However, KCN resulted in conversion of the major part of aHMol1P into aHMol(1,6)P2. Residual inhibition of glycogenolysis was due to aHMol1P. Indeed, the subsequent withdrawal of aHMol caused a further gradual decrease in the proportion of aHMol1P (being converted into aHMol(1,6)P2, in the absence of de novo aHMol1P synthesis), and this resulted in a gradual de-inhibition of glycogenolysis, in the absence of marked changes in Pi. Glycogenolytic rates were consistently predicted by a model assuming non-saturated Pi kinetics and competition by aHMol1P exclusively: In conclusion, limited Pi availability and the presence of competitive inhibitors are decisive factors in the control of the in situ catalytic potential of phosphorylase a.
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Affiliation(s)
- K Bruynseels
- Biomedical NMR Unit, Department of Radiology, Leuven, Belgium
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16
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Murakami T, Shimomura Y, Fujitsuka N, Sokabe M, Okamura K, Sakamoto S. Enlargement glycogen store in rat liver and muscle by fructose-diet intake and exercise training. J Appl Physiol (1985) 1997; 82:772-5. [PMID: 9074962 DOI: 10.1152/jappl.1997.82.3.772] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
This study investigated the effect of long-term intake of a fructose diet and exercise training on glycogen content in liver and skeletal muscle in female rats. Thirty-six rats (8 wk old) were divided into two dietary groups and were fed with a control (chow) diet or fructose diet (containing 20%) fructose) for 12 wk. During this period, one-half of the rats in each dietary group were trained by using a motor-driven treadmill (running speed of 25 m/min and duration of 90 min/day, 5 days/wk). The liver glycogen was increased by intake of a fructose diet and exercise training, and the content was in the following order: control-diet and sedentary rats < fructose-diet and sedentary rats < or = control-diet and trained rats < fructose-diet and trained rats in the ratio of 1:3.4:3.6:5.0. The glycogen content in gastrocnemius muscle showed the same trend as that in liver; the ratio was 1:1.3:1.3:1.6. These results indicate that both long-term intake of the fructose diet and exercise training synergistically increased glycogen in both tissues.
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Affiliation(s)
- T Murakami
- Department of Bioscience, Nagoya Institute of Technology, Gokiso, Japan
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Hellerstein MK, Neese RA, Schwarz JM, Turner S, Faix D, Wu K. Altered fluxes responsible for reduced hepatic glucose production and gluconeogenesis by exogenous glucose in rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:E163-72. [PMID: 9038866 DOI: 10.1152/ajpendo.1997.272.1.e163] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The net release of glucose from the liver, or hepatic glucose production (HGP), and apparent gluconeogenesis (GNG) are reduced by exogenous glucose. We investigated the changes in metabolic fluxes responsible. Flux through the hepatic GNG pathway was quantified by mass isotopomer distribution analysis (MIDA) from [2-13C]glycerol. Unidirectional flux across hepatic glucose-6-phosphatase (G-6-Pase), or total hepatic glucose output (THGO), and hepatic glucose cycling (HGC) were also measured by using glucuronate (GlcUA) to correct for glucose 6-phosphate (G-6-P) labeling. Infusion of glucose (15-30 mg.kg-1.min-1 iv) to 24 h-fasted rats caused two important metabolic alterations. First was a significant increase in hepatic glucose uptake and HGC: > 60% of THGO was from HGC. Second, although flux through hepatic G-6-P increased (from 15.7 to 17.7-22.7 mg.kg-1.min-1), the partitioning of G-6-P flux changed markedly [from 30-35% to 55-60% entering UDP-glucose (UDP-Glc), P < 0.01]. Total flux through the GNG pathway remained active during intravenous glucose, but increased partitioning into UDP-Glc lowered GNG flux plasma glucose by 50%. In summary, the suppression of HGP and GNG flux into glucose is not primarily due to reduced carbon flow through hepatic G-6-Pase or the hepatic GNG pathway. THGO persists, but hepatic G-6-P is derived increasingly from plasma glucose, and flow through GNG persists, but the partitioning coefficient of G-6-P into UDP-Glc doubles. These adjustments permit net HGP to fall despite increased total production of hepatic G-6-P during administration of glucose.
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Affiliation(s)
- M K Hellerstein
- Department of Nutritional Sciences, University of California, Berkeley 94720-3104, USA
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18
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Laouari D, Jurkovitz C, Burtin M, Bois B, Vassault A, Kleinknecht C. Uremia-induced disturbances in hepatic carbohydrate metabolism: enhancement by sucrose feeding. Metabolism 1994; 43:403-12. [PMID: 8159094 DOI: 10.1016/0026-0495(94)90067-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A high-sucrose (S) diet accentuates anorexia and stunts growth in uremic (U) rats, and an oral S load induces a greater hyperfructosemia in U rats than in control (C) rats. Four studies were performed to determine the roles of S feeding and an acute S load on liver carbohydrate (CHO) metabolism in U and C rats (eight to 10 rats per group). We also examined the plasma responses to either water or a S load. Levels of the main metabolites of glycolysis, gluconeogenesis, and glycogenesis were measured under basal conditions (7 hours' postmeal) in U and C rats fed either a cornstarch diet (study I) or S diet (study II) and at 30 and 60 minutes after an intragastric S load (studies III and IV) in s-fed U and C rats. The weight gain, food intake, and plasma creatinine and urea levels of the rats in the four studies were comparable. Weight gain and liver weight (g/100 g body weight) were lower in U than in C rats. In the plasma, baseline levels of lactate were decreased by uremia and S feeding and those of glucose (G) were increased by S feeding. The increases in plasma G and fructose (F) levels after a S load were greater in U rats than in C rats, whereas those of plasma lactate were comparable. In the liver under basal conditions, uremia markedly decreased levels of glycogen, F-1,6-diphosphate (F-1,6-diP), F-2,6-diP, 3-glycero-phosphate (3-glycero-P), dihydroxyacetone phosphate (DHAP), pyruvate, lactate, and adenosine triphosphate (ATP), and the phosphorylation state (ATP/adenosine diphosphate [ADP] x inorganic phosphorus [PI]), increased phosphoenolpyruvate (PEP), ADP, and Pi levels, but did not affect the cytosolic redox state (pyruvate/lactate). In addition to uremia, S feeding further decreased levels of glycogen, F-2,6-diP, 3-glycero-P, and ATP. After S loading, liver F levels increased more in U than in C rats, but glycogen and 3-glycero-P levels increased less in U than in C rats. Liver lactate and pyruvate levels increased more in U than in C rats, and the pyruvate/lactate and DHAP/3-glycero-P ratios were higher in U than in C rats after a S load. The ATP level and the phosphorylation state in U rats increased 30 minutes later in U than in C rats. Our findings indicate that uremia causes a depletion in liver glycogen, which is enhanced by S feeding and could be partially attributed to decreased glycogen synthesis.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- D Laouari
- INSERM U.192, Hôpital des Enfants Malades, Paris, France
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19
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Zhang Z, Radziuk J. Coordinated regulation of hepatic glycogen formation in perfused rat liver by glucose and lactate. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 266:E583-91. [PMID: 8178979 DOI: 10.1152/ajpendo.1994.266.4.e583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Lactate has been found to enhance the formation of glycogen from both glucose and lactate as substrate (Z. Zhang and J. Radziuk. Biochem. J. 280: 415-419, 1991). To evaluate the relative importance of its role as substrate and regulatory factor, a dual dose-response evaluation was done by adding variable amounts of glucose and lactate to the medium in a recirculating perfused rat liver preparation. Nine groups of perfusions were performed utilizing three different levels of carbon infusion into the system: 0.25, 1.0, and 2.0 mg/min. These levels of carbon infusion were further subdivided into different relative amounts of glucose and lactate. Lactate uptake by the perfused liver was linearly related with net glucose output, regardless of the glucose concentrations. In contrast to this, the effect of lactate uptake on the rate of glycogen synthesis is saturable. Moreover, the rate of glycogen formation at which this saturation occurs is dependent only on the mean perfusate glucose concentration. The highest amount of glycogen formed in a 2-h period was 50 +/- 7 mg and the lowest 3.4 +/- 0.3 mg. A family of dose-response curves was generated describing this dual dependence of glycogen formation (both direct and gluconeogenetic pathways) on lactate and glucose.
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Affiliation(s)
- Z Zhang
- Department of Medicine and Physiology, University of Ottawa, Ontario, Canada
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20
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Nuttall F, Gannon M. Allosteric regulation of glycogen synthase in liver. A physiological dilemma. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)38650-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Radziuk J, Pye S, Zhang Z. Substrates and the regulation of hepatic glycogen metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 334:235-52. [PMID: 8249686 DOI: 10.1007/978-1-4615-2910-1_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Glycogen metabolism is a complex process which depends on the metabolic circumstances and the hormonal milieu. In this overview an intriguing new possibility has been emphasized--the possible central role of lactate in coordinating, with glucose, the net synthesis of glycogen. Since lactate changes acutely under many physiological circumstances, it would be a logical candidate for a signal which communicates to the liver the metabolic states of the periphery. It would then acutely determine the synthetic rate of glycogen synthesis within the range determined by the glucose concentrations which in turn could be said to reflect the nutritional state of the system. Interestingly, after oral glucose loading, portal glucose levels would be about 25% higher (Radziuk et al., 1978) relative to arterial. As seen from Figs 8 and 9 however the glycogen synthetic rate appears very sensitive to glucose (at a given lactate uptake). Everything else being assumed equal therefore, more glycogen would be synthesized than during intravenous loading with an equivalent peripheral concentration. This is indeed the case (Shulman and Rossetti, 1989). On the other hand, during equivalent loads, peripheral glucose levels are higher and the same quantity of glycogen is synthesized (Radziuk, 1989a, 1989b). If lactate is typical of other glucogenic substrates, then it is also logical that mixed meals with higher levels of portal substrate would maximize glycogen synthetic rates. Similarly, in diabetes where hyperglycemia and hyperlactatemia prevail, gluconeogenesis plays a predominant role in glycogen synthesis (Giaccari and Rossetti, 1992).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Radziuk
- Diabetes and Metabolism Research Unit, Ottawa Civic Hospital, Canada
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22
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Robbins BL, Foster JD, Nordlie RC. Metabolic intermediates as potential regulators of glucose-6-phosphatase. Life Sci 1991; 48:1075-81. [PMID: 1847732 DOI: 10.1016/0024-3205(91)90509-a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Twenty-five metabolites of glucose, gluconeogenic substrates, and related compounds were examined as potential inhibitors of glucose-6-phosphatase (EC 3.1.3.9) catalytic unit and substrate transport function, using disrupted and intact rat liver microsomes. Inhibitions (competitive) were noted with six. Calculated per cent inhibitions with presumed near-physiologic concentrations of inhibitor and substrate were small. However, when hepatic fructose-1-P concentration is elevated in response to a fructose load, inhibition of glucose-6-phosphatase by fructose-1-P may play a regulatory role, along with fructose-1-P-associated deinhibition of glucokinase, by directing glucose-6-P away from glucose formation and towards glycogen synthesis and glycolysis.
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Affiliation(s)
- B L Robbins
- Department of Biochemistry and Molecular Biology, University of North Dakota, School of Medicine, Grand Forks 58202
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Davies DR, Detheux M, Van Schaftingen E. Fructose 1-phosphate and the regulation of glucokinase activity in isolated hepatocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 192:283-9. [PMID: 2145154 DOI: 10.1111/j.1432-1033.1990.tb19225.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Fructose 1-phosphate kinase was partially purified from Clostridium difficile and used to develop specific assays of fructose 1-phosphate and fructose. The concentration of fructose 1-phosphate was below the detection limit of the assay (25 pmol/mg protein) in hepatocytes incubated in the presence of glucose as sole carbohydrate. Addition of fructose (0.05-1 mM) caused a concentration-dependent and transient increase in the fructose 1-phosphate content. Glucagon (1 microM) and ethanol (10 mM) caused a severalfold decrease in the concentration of fructose 1-phosphate in cells incubated with fructose, whereas the addition of 0.1 microM vasopressin or 10 mM glycerone, or raising the concentration of glucose from 5 mM to 20 mM had the opposite effect. All these agents caused changes in the concentration of triose phosphates that almost paralleled those of the fructose 1-phosphate concentration. Sorbitol had a similar effect to fructose in causing the formation of fructose 1-phosphate. D-Glyceraldehyde was much less potent in this respect than the ketose and its effect disappeared earlier. The effect of D-glyceraldehyde was reinforced by an increase in the glucose concentration and decreased by glucagon. Both fructose and D-glyceraldehyde stimulated the phosphorylation of glucose as estimated by the release of 3H2O from [2-3H]glucose, but the triose was less potent in this respect than fructose and its effect disappeared earlier. Glucagon and ethanol antagonised the effect of low concentrations of fructose or D-glyceraldehyde on the detritiation of glucose. These results support the proposal that fructose 1-phosphate mediates the effects of fructose, D-glyceraldehyde and sorbitol by relieving the inhibition exerted on glucokinase by a regulatory protein.
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Affiliation(s)
- D R Davies
- Laboratoire de Chimie physiologique, International Institute of Cellular and Molecular Pathology, Brussels, Belgium
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Dobson GP, Veech RL, Passonneau JV, Huang MT. In vivo portal-hepatic venous gradients of glycogenic precursors and incorporation of D-[3-3H]glucose into liver glycogen in the awake rat. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)46230-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Van Schaftingen E, Vandercammen A. Stimulation of glucose phosphorylation by fructose in isolated rat hepatocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 179:173-7. [PMID: 2917559 DOI: 10.1111/j.1432-1033.1989.tb14537.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The phosphorylation of glucose was measured by the formation of [3H]H2O from [2-3H]glucose in suspensions of freshly isolated rat hepatocytes. Fructose (0.2 mM) stimulated 2-4-fold the rate of phosphorylation of 5 mM glucose although not of 40 mM glucose, thus increasing the apparent affinity of the glucose phosphorylating system. A half-maximal stimulatory effect was observed at about 50 microM fructose. Stimulation was maximal 5 min after addition of the ketose and was stable for at least 40 min, during which period 60% of the fructose was consumed. The effect of fructose was reversible upon removal of the ketose. Sorbitol and tagatose were as potent as fructose in stimulating the phosphorylation of 5 mM glucose. D-Glyceraldehyde also had a stimulatory effect but at tenfold higher concentrations. In contrast, dihydroxyacetone had no significant effect and glycerol inhibited the detritiation of glucose. Oleate did not affect the phosphorylation of glucose, even in the presence of fructose, although it stimulated the formation of ketone bodies severalfold, indicating that it was converted to its acyl-CoA derivative. These results allow the conclusion that fructose stimulates glucokinase in the intact hepatocyte. They also suggest that this effect is mediated through the formation of fructose 1-phosphate, which presumably interacts with a competitive inhibitor of glucokinase other than long-chain acyl-CoAs.
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Affiliation(s)
- E Van Schaftingen
- Laboratoire de Chimie Physiologique, Université Catholique de Louvain, Belgium
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Youn JH, Ader M, Bergman RN. Glucose phosphorylation is not rate limiting for accumulation of glycogen from glucose in perfused livers from fasted rats. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(17)31238-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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