1
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Many GM, Sanford JA, Sagendorf TJ, Hou Z, Nigro P, Whytock KL, Amar D, Caputo T, Gay NR, Gaul DA, Hirshman MF, Jimenez-Morales D, Lindholm ME, Muehlbauer MJ, Vamvini M, Bergman BC, Fernández FM, Goodyear LJ, Hevener AL, Ortlund EA, Sparks LM, Xia A, Adkins JN, Bodine SC, Newgard CB, Schenk S. Sexual dimorphism and the multi-omic response to exercise training in rat subcutaneous white adipose tissue. Nat Metab 2024; 6:963-979. [PMID: 38693320 PMCID: PMC11132991 DOI: 10.1038/s42255-023-00959-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 12/01/2023] [Indexed: 05/03/2024]
Abstract
Subcutaneous white adipose tissue (scWAT) is a dynamic storage and secretory organ that regulates systemic homeostasis, yet the impact of endurance exercise training (ExT) and sex on its molecular landscape is not fully established. Utilizing an integrative multi-omics approach, and leveraging data generated by the Molecular Transducers of Physical Activity Consortium (MoTrPAC), we show profound sexual dimorphism in the scWAT of sedentary rats and in the dynamic response of this tissue to ExT. Specifically, the scWAT of sedentary females displays -omic signatures related to insulin signaling and adipogenesis, whereas the scWAT of sedentary males is enriched in terms related to aerobic metabolism. These sex-specific -omic signatures are preserved or amplified with ExT. Integration of multi-omic analyses with phenotypic measures identifies molecular hubs predicted to drive sexually distinct responses to training. Overall, this study underscores the powerful impact of sex on adipose tissue biology and provides a rich resource to investigate the scWAT response to ExT.
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Affiliation(s)
- Gina M Many
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - James A Sanford
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Tyler J Sagendorf
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Zhenxin Hou
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Pasquale Nigro
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Katie L Whytock
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - David Amar
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Tiziana Caputo
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Nicole R Gay
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - David A Gaul
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
| | - Michael F Hirshman
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - David Jimenez-Morales
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Malene E Lindholm
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Michael J Muehlbauer
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC, USA
| | - Maria Vamvini
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Bryan C Bergman
- Division of Endocrinology, Diabetes, and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Facundo M Fernández
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
| | - Laurie J Goodyear
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Andrea L Hevener
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, University of California, Los Angeles, CA, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Lauren M Sparks
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Ashley Xia
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Joshua N Adkins
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA.
| | - Sue C Bodine
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
| | - Christopher B Newgard
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC, USA.
| | - Simon Schenk
- Department of Orthopaedic Surgery, School of Medicine, University of California San Diego, La Jolla, CA, USA.
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2
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Wagner VA, Holl KL, Clark KC, Reho JJ, Lehmler HJ, Wang K, Grobe JL, Dwinell MR, Raff H, Kwitek AE. The Power of the Heterogeneous Stock Rat Founder Strains in Modeling Metabolic Disease. Endocrinology 2023; 164:bqad157. [PMID: 37882530 PMCID: PMC10637104 DOI: 10.1210/endocr/bqad157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/04/2023] [Accepted: 10/24/2023] [Indexed: 10/27/2023]
Abstract
Metabolic diseases are a host of complex conditions, including obesity, diabetes mellitus, and metabolic syndrome. Endocrine control systems (eg, adrenals, thyroid, gonads) are causally linked to metabolic health outcomes. N/NIH Heterogeneous Stock (HS) rats are a genetically heterogeneous outbred population developed for genetic studies of complex traits. Genetic mapping studies in adult HS rats identified loci associated with cardiometabolic risks, such as glucose intolerance, insulin resistance, and increased body mass index. This study determined underappreciated metabolic health traits and the associated endocrine glands within available substrains of the HS rat founders. We hypothesize that the genetic diversity of the HS rat founder strains causes a range of endocrine health conditions contributing to the diversity of cardiometabolic disease risks. ACI/EurMcwi, BN/NHsdMcwi, BUF/MnaMcwi, F344/StmMcwi, M520/NRrrcMcwi, and WKY/NCrl rats of both sexes were studied from birth until 13 weeks of age. Birth weight was recorded, body weight was measured weekly, metabolic characteristics were assessed, and blood and tissues were collected. Our data show wide variation in endocrine traits and metabolic health states in ACI, BN, BUF, F344, M520, and WKY rat strains. This is the first report to compare birth weight, resting metabolic rate, endocrine gland weight, hypothalamic-pituitary-thyroid axis hormones, and brown adipose tissue weight in these rat strains. Importantly, this work unveils new potential for the HS rat population to model early life adversity and adrenal and thyroid pathophysiology. The HS population likely inherited risk alleles for these strain-specific traits, making the HS rat a powerful model to investigate interventions on endocrine and metabolic health.
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Affiliation(s)
- Valerie A Wagner
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Katie L Holl
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Karen C Clark
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - John J Reho
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, USA
| | - Kai Wang
- Department of Biostatistics, University of Iowa, Iowa City, IA 52242, USA
| | - Justin L Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Melinda R Dwinell
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Hershel Raff
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Endocrine Research Laboratory, Aurora St. Luke's Medical Center, Advocate Aurora Research Institute, Milwaukee, WI 53233, USA
| | - Anne E Kwitek
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Rat Genome Database, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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3
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Many GM, Sanford JA, Sagendorf TJ, Hou Z, Nigro P, Whytock K, Amar D, Caputo T, Gay NR, Gaul DA, Hirshman M, Jimenez-Morales D, Lindholm ME, Muehlbauer MJ, Vamvini M, Bergman B, Fern Ndez FM, Goodyear LJ, Ortlund EA, Sparks LM, Xia A, Adkins JN, Bodine SC, Newgard CB, Schenk S. Sexual dimorphism and the multi-omic response to exercise training in rat subcutaneous white adipose tissue. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.527012. [PMID: 36778330 PMCID: PMC9915732 DOI: 10.1101/2023.02.03.527012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Subcutaneous white adipose tissue (scWAT) is a dynamic storage and secretory organ that regulates systemic homeostasis, yet the impact of endurance exercise training and sex on its molecular landscape has not been fully established. Utilizing an integrative multi-omics approach with data generated by the Molecular Transducers of Physical Activity Consortium (MoTrPAC), we identified profound sexual dimorphism in the dynamic response of rat scWAT to endurance exercise training. Despite similar cardiorespiratory improvements, only male rats reduced whole-body adiposity, scWAT adipocyte size, and total scWAT triglyceride abundance with training. Multi-omic analyses of adipose tissue integrated with phenotypic measures identified sex-specific training responses including enrichment of mTOR signaling in females, while males displayed enhanced mitochondrial ribosome biogenesis and oxidative metabolism. Overall, this study reinforces our understanding that sex impacts scWAT biology and provides a rich resource to interrogate responses of scWAT to endurance training.
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Fauste E, Panadero MI, Donis C, Otero P, Bocos C. Pregnancy Is Enough to Provoke Deleterious Effects in Descendants of Fructose-Fed Mothers and Their Fetuses. Nutrients 2021; 13:3667. [PMID: 34684668 PMCID: PMC8539712 DOI: 10.3390/nu13103667] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 01/06/2023] Open
Abstract
The role of fructose in the global obesity and metabolic syndrome epidemic is widely recognized. However, its consumption is allowed during pregnancy. We have previously demonstrated that maternal fructose intake in rats induces detrimental effects in fetuses. However, these effects only appeared in adult descendants after a re-exposure to fructose. Pregnancy is a physiological state that leads to profound changes in metabolism and hormone response. Therefore, we wanted to establish if pregnancy in the progeny of fructose-fed mothers was also able to provoke an unhealthy situation. Pregnant rats from fructose-fed mothers (10% w/v) subjected (FF) or not (FC) to a fructose supplementation were studied and compared to pregnant control rats (CC). An OGTT was performed on the 20th day of gestation, and they were sacrificed on the 21st day. Plasma and tissues from mothers and fetuses were analyzed. Although FF mothers showed higher AUC insulin values after OGTT in comparison to FC and CC rats, ISI was lower and leptinemia was higher in FC and FF rats than in the CC group. Accordingly, lipid accretion was observed both in liver and placenta in the FC and FF groups. Interestingly, fetuses from FC and FF mothers also showed the same profile observed in their mothers on lipid accumulation, leptinemia, and ISI. Moreover, hepatic lipid peroxidation was even more augmented in fetuses from FC dams than those of FF mothers. Maternal fructose intake produces in female progeny changes that alter their own pregnancy, leading to deleterious effects in their fetuses.
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Affiliation(s)
| | | | | | | | - Carlos Bocos
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain; (E.F.); (M.I.P.); (C.D.); (P.O.)
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5
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Likitnukul S, Kalandakanond-Thongsong S, Thammacharoen S. Evidence of growth hormone effect on plasma leptin in diet-induced obesity and diet-resistant rats. ASIAN BIOMED 2019. [DOI: 10.1515/abm-2019-0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Background
Plasma leptin is regulated by several factors, including growth hormone (GH), which influences the pathophysiology of obesity.
Objective
To demonstrate the short-term effect of GH on plasma leptin levels in 3 conditions in vivo with the different amount of body fat mass.
Methods
Adult male Wistar rats were fed with standard chow or hypercaloric diet (HC). The HC rats were demonstrated as HC-feeding obese (HC-O) and HC-feeding resistant (HC-R) rats. Then, they were treated with GH or saline for 3 days. Basal plasma leptin levels were measured at 24 and 32 h. For meal-induced condition, all rats were fed for 2 hand plasma leptin was measured. Further 16-h fasting period, plasma leptin, insulin, and insulin sensitivity indexes were determined.
Results
The short-term GH treatment decreased basal plasma leptin at 32 h after the first GH injection in HC-O rats. However, GH treatment had no effect on meal-induced plasma leptin in all rats. Furthermore, GH treatment attenuated fasting effect on plasma leptin in control and HC-R rats. The insulin resistance (IR) induced by the short-term GH treatment was demonstrated by higher fasting plasma insulin and the increased homeostasis model of IR in HC-R rats.
Conclusions
The study demonstrates the important role of greater fat mass in HC-O rats, which results in decreased basal plasma leptin after short-term GH treatment. For meal-induced condition, GH had no effect on plasma leptin in all rats. Interestingly, GH could attenuate fasting effect on plasma leptin in rats that have lower fat mass.
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Affiliation(s)
- Sutharinee Likitnukul
- Department of Veterinary Physiology, Faculty of Veterinary Science, Chulalongkorn University , Bangkok 10330 , Thailand
| | | | - Sumpun Thammacharoen
- Department of Veterinary Physiology, Faculty of Veterinary Science, Chulalongkorn University , Bangkok 10330 , Thailand
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Perry RJ, Shulman GI. The Role of Leptin in Maintaining Plasma Glucose During Starvation. POSTDOC JOURNAL : A JOURNAL OF POSTDOCTORAL RESEARCH AND POSTDOCTORAL AFFAIRS 2018; 6:3-19. [PMID: 29682594 PMCID: PMC5909716 DOI: 10.14304/surya.jpr.v6n3.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For 20 years it has been known that concentrations of leptin, a hormone produced by the white adipose tissue (WAT) largely in proportion to body fat, drops precipitously with starvation, particularly in lean humans and animals. The role of leptin to suppress the thyroid and reproductive axes during a prolonged fast has been well defined; however, the impact of leptin on metabolic regulation has been incompletely understood. However emerging evidence suggests that, in starvation, hypoleptinemia increases activity of the hypothalamic-pituitary-adrenal axis, promoting WAT lipolysis, increasing hepatic acetyl-CoA concentrations, and maintaining euglycemia. In addition, leptin may be largely responsible for mediating a shift from a reliance upon glucose metabolism (absorption and glycogenolysis) to fat metabolism (lipolysis increasing gluconeogenesis) which preserves substrates for the brain, heart, and other critical organs. In this way a leptin-mediated glucose-fatty acid cycle appears to maintain glycemia and permit survival in starvation.
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Affiliation(s)
- Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine
- Department of Cellular & Molecular Physiology, Yale University School of Medicine
- Howard Hughes Medical Institute
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7
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Fructuoso M, Rachdi L, Philippe E, Denis RG, Magnan C, Le Stunff H, Janel N, Dierssen M. Increased levels of inflammatory plasma markers and obesity risk in a mouse model of Down syndrome. Free Radic Biol Med 2018; 114:122-130. [PMID: 28958596 DOI: 10.1016/j.freeradbiomed.2017.09.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/20/2017] [Accepted: 09/24/2017] [Indexed: 12/27/2022]
Abstract
Down syndrome (DS) is caused by the trisomy of human chromosome 21 and is the most common genetic cause of intellectual disability. In addition to the intellectual deficiencies and physical anomalies, DS individuals present a higher prevalence of obesity and subsequent metabolic disorders than healthy adults. There is increasing evidence from both clinical and experimental studies indicating the association of visceral obesity with a pro-inflammatory status and recent studies have reported that obese people with DS suffer from low-grade systemic inflammation. However, the link between adiposity and inflammation has not been explored in DS. Here we used Ts65Dn mice, a validated DS mouse model, for the study of obesity-related inflammatory markers. Ts65Dn mice presented increased energy intake, and a positive energy balance leading to increased adiposity (fat mass per body weight), but did not show overweight, which only was apparent upon high fat diet induced obesity. Trisomic mice also had fasting hyperglycemia and hypoinsulinemia, and normal incretin levels. Those trisomy-associated changes were accompanied by reduced ghrelin plasma levels and slightly but not significantly increased leptin levels. Upon a glucose load, Ts65Dn mice showed normal increase of incretins accompanied by over-responses of leptin and resistin, while maintaining the hyperglycemic and hypoinsulinemic phenotype. These changes in the adipoinsular axis were accompanied by increased plasma levels of inflammatory biomarkers previously correlated with obesity galectin-3 and HSP72, and reduced IL-6. Taken together, these results suggest that increased adiposity, and pro-inflammatory adipokines leading to low-grade inflammation are important players in the propensity to obesity in DS. We conclude that DS would be a case of impaired metabolic-inflammatory axis.
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Affiliation(s)
- M Fructuoso
- Cellular & Systems Neurobiology, Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - L Rachdi
- INSERM U1016, Cochin Institute, Paris, France; CNRS UMR 8104, Paris, France; University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - E Philippe
- Université Paris Diderot, Sorbonne Paris Cité, Unité Biologie Fonctionnelle et Adaptative - CNRS UMR 8251, Paris, France
| | - R G Denis
- Université Paris Diderot, Sorbonne Paris Cité, Unité Biologie Fonctionnelle et Adaptative - CNRS UMR 8251, Paris, France
| | - C Magnan
- Université Paris Diderot, Sorbonne Paris Cité, Unité Biologie Fonctionnelle et Adaptative - CNRS UMR 8251, Paris, France
| | - H Le Stunff
- Université Paris Diderot, Sorbonne Paris Cité, Unité Biologie Fonctionnelle et Adaptative - CNRS UMR 8251, Paris, France; Université Paris Sud, France
| | - N Janel
- Université Paris Diderot, Sorbonne Paris Cité, Unité Biologie Fonctionnelle et Adaptative - CNRS UMR 8251, Paris, France
| | - M Dierssen
- Cellular & Systems Neurobiology, Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
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8
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Differential response of rat strains to obesogenic diets underlines the importance of genetic makeup of an individual towards obesity. Sci Rep 2017; 7:9162. [PMID: 28831087 PMCID: PMC5567335 DOI: 10.1038/s41598-017-09149-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 07/24/2017] [Indexed: 11/23/2022] Open
Abstract
Obesity, a multifactorial disorder, results from a chronic imbalance of energy intake vs. expenditure. Apart from excessive consumption of high calorie diet, genetic predisposition also seems to be equally important for the development of obesity. However, the role of genetic predisposition in the etiology of obesity has not been clearly delineated. The present study addresses this problem by selecting three rat strains (WNIN, F-344, SD) with different genetic backgrounds and exposing them to high calorie diets. Rat strains were fed HF, HS, and HFS diets and assessed for physical, metabolic, biochemical, inflammatory responses, and mRNA expression. Under these conditions: significant increase in body weight, visceral adiposity, oxidative stress and systemic pro-inflammatory status; the hallmarks of central obesity were noticed only in WNIN. Further, they developed altered glucose and lipid homeostasis by exhibiting insulin resistance, impaired glucose tolerance, dyslipidemia and fatty liver condition. The present study demonstrates that WNIN is more prone to develop obesity and associated co-morbidities under high calorie environment. It thus underlines the cumulative role of genetics (nature) and diet (nurture) towards the development of obesity, which is critical for understanding this epidemic and devising new strategies to control and manage this modern malady.
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Ethanol extracts of unroasted Coffea canephora robusta beans suppress adipogenesis in preadipocytes and fat accumulation in rats fed a high-fat diet. Food Sci Biotechnol 2014. [DOI: 10.1007/s10068-014-0276-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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10
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Azzout-Marniche D, Chaumontet C, Nadkarni NA, Piedcoq J, Fromentin G, Tomé D, Even PC. Food intake and energy expenditure are increased in high-fat-sensitive but not in high-carbohydrate-sensitive obesity-prone rats. Am J Physiol Regul Integr Comp Physiol 2014; 307:R299-309. [DOI: 10.1152/ajpregu.00065.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Obesity-prone (OP) rodents are used as models of human obesity predisposition. The goal of the present study was to identify preexisting defects in energy expenditure components in OP rats. Two studies were performed. In the first one, male Wistar rats ( n = 48) were fed a high-carbohydrate diet (HCD) for 3 wk and then a high-fat diet (HFD) for the next 3 wk. This study showed that adiposity gain under HCD was 2.9-fold larger in carbohydrate-sensitive (CS) than in carbohydrate-resistant (CR) rats, confirming the concept of “carbohydrate-sensitive” rats. Energy expenditure (EE), respiratory quotient (RQ), caloric intake (CI), and locomotor activity measured during HFD identified no differences in EE and RQ between fat-resistant (FR) and fat-sensitive (FS) rats, and indicated that obesity developed in FS rats only as the result of a larger CI not fully compensated by a parallel increase in EE. A specific pattern of spontaneous activity, characterized by reduced activity burst intensity, was identified in FS rats but not in CS ones. This mirrors a previous observation that under HCD, CS but not FS rats, exhibited bursts of activity of reduced intensity. In a second study, rats were fed a HFD for 3 wk, and the components of energy expenditure were examined by indirect calorimetry in 10 FR and 10 FS rats. This study confirmed that a low basal EE, reduced thermic effect of feeding, defective postprandial energy partitioning, or a defective substrate utilization by the working muscle are not involved in the FS phenotype.
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Affiliation(s)
- Dalila Azzout-Marniche
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Catherine Chaumontet
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Nachiket A. Nadkarni
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Julien Piedcoq
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Gilles Fromentin
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Daniel Tomé
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Patrick C. Even
- Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine d'Ile-de-France (CRNH-IdF), UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France; and
- AgroParisTech, CRNH-IdF, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
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11
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Rodríguez L, Panadero MI, Roglans N, Otero P, Alvarez-Millán JJ, Laguna JC, Bocos C. Fructose during pregnancy affects maternal and fetal leptin signaling. J Nutr Biochem 2013; 24:1709-16. [PMID: 23643523 DOI: 10.1016/j.jnutbio.2013.02.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/21/2013] [Accepted: 02/26/2013] [Indexed: 12/31/2022]
Abstract
Fructose intake from added sugars correlates with the epidemic rise in obesity, metabolic syndrome and cardiovascular diseases. Fructose intake also causes features of metabolic syndrome in laboratory animals. Therefore, we have investigated whether fructose modifies lipidemia in pregnant rats and produces changes in their fetuses. Thus, fructose administration (10% wt/vol.) in the drinking water of rats throughout gestation leads to maternal hypertriglyceridemia. This change was not observed in glucose-fed rats, although both carbohydrates produced similar changes in liver triglycerides and in the expression of transcription factors and enzymes involved in lipogenesis. After fasting overnight, mothers fed with carbohydrates were found to be hyperleptinemic. However, after a bolus of glucose, leptinemia in fructose-fed mothers showed no response, whereas it increased in parallel in glucose-fed and control mothers. Fetuses from fructose-fed mothers showed hypotriglyceridemia and a higher hepatic triglyceride content than fetuses from control or glucose-fed mothers. A higher expression of genes related to lipogenesis and a lower expression of fatty acid catabolism genes were also found in fetuses from fructose-fed mothers. Moreover, although hyperleptinemic, these fetuses exhibited increased tyrosine phosphorylation of the signal transducer and activator of transcription-3 (STAT-3) protein, without a parallel increase in the serine phosphorylation of STAT-3 nor in the suppressor of cytokine signaling-3 protein levels whose expression is regulated by leptin through STAT-3 activation. Thus, fructose intake during gestation provoked a diminished maternal leptin response to fasting and refeeding and an impairment in the transduction of the leptin signal in the fetuses, which could be responsible for their hepatic steatosis.
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Affiliation(s)
- Lourdes Rodríguez
- Facultades de Farmacia y Medicina, Universidad San Pablo-CEU, Montepríncipe, Boadilla del Monte, Madrid, Spain
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Silk and silkworm pupa peptides suppress adipogenesis in preadipocytes and fat accumulation in rats fed a high-fat diet. Eur J Nutr 2011; 51:1011-9. [DOI: 10.1007/s00394-011-0280-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 11/14/2011] [Indexed: 10/14/2022]
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Dos Santos ZA, Da Silva RJ, Bacurau RFP, Tirapegui J, Ribeiro SML. Effect of food restriction and intense physical training on estrous cyclicity and plasma leptin concentrations in rats. J Nutr Sci Vitaminol (Tokyo) 2011; 57:1-8. [PMID: 21512284 DOI: 10.3177/jnsv.57.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Intense physical training and dietary energy restriction have been associated with consequences such as nutritional amenorrhea. We investigated the effects of intense physical training, food restriction or the combination of both strategies on estrous cyclicity in female rats, and the relationship between leptin ad these effects. Twenty-seven female Wistar rats were distributed into four groups: SF: sedentary, fed ad libitum; SR: sedentary subjected to 50% food restriction (based on the food intake of their fed counterparts); TF: trained (physical training on a motor treadmill with a gradual increase in speed and time), fed ad libitum; TR: trained with 50% food restriction. We analysed estrous cyclicity, plasma leptin and estradiol as well as chemical composition of the carcass, body weight variation, and weight of ovaries and perirenal adipose tissue. Data demonstrate that physical training alone was not responsible for significant modifications in either carcass chemical composition or reproductive function. Food restriction reduced leptin levels in all animals and interrupted the estrous cyclicity in some animals, but only the combination of food restriction and physical training was capable of interrupting the estrous cyclicity in all animals. Leptin was not directly related to estrous cyclicity. From our findings, it may be concluded that there is an additive or synergistic effect of energy intake restriction and energy expenditure by intense physical training on estrous cyclicity. Leptin appears to be one among others factors related to estrous cycle, but it probably acts indirectly.
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14
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Liver TAG transiently decreases while PL n-3 and n-6 fatty acids are persistently elevated in insulin resistant mice. Lipids 2008; 43:1039-51. [PMID: 18763007 DOI: 10.1007/s11745-008-3220-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 07/24/2008] [Accepted: 07/24/2008] [Indexed: 01/08/2023]
Abstract
Changes in fatty acid metabolism associated with insulin resistance have been described in rats and humans but have not been well characterized in the frequently used mouse model of diet-induced obesity. To analyse the early phase as well as established insulin resistance, C57BL/6 mice were placed for 1 or 16 weeks on a high fat diet (1w-HFD, 16w-HFD). Endocrine and metabolic parameters indicated that 1w-HFD mice showed a moderate but significant induction of insulin resistance while 16w-HFD mice exhibited profound obesity-associated insulin resistance and dyslipidemias. Significant alterations in fatty acid composition were observed in plasma and liver in both groups. Liver phospholipid-associated arachidonate and docosahexaenoate were increased in both 1w-HFD and 16w-HFD mice, possibly due to increased expression of the desaturases Fads1 and Fads2. Unexpectedly, SCD1 activity and gene expression in liver were decreased in the 1w-HFD group accompanied by diminished total hepatic lipid levels, while they were increased in chronically fed mice. Our data indicate that the early phase of HFD-induced insulin resistance is not associated with elevated liver lipid concentration. Furthermore, the early and persistent rise of arachidonate and docosahexaenoate indicates that insulin resistance is not due to insufficient availability (or concentrations) of polyunsaturated fatty acids as postulated previously.
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15
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Gilliam-Davis S, Payne VS, Kasper SO, Tommasi EN, Robbins ME, Diz DI. Long-term AT1 receptor blockade improves metabolic function and provides renoprotection in Fischer-344 rats. Am J Physiol Heart Circ Physiol 2007; 293:H1327-33. [PMID: 17616746 DOI: 10.1152/ajpheart.00457.2007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fischer-344 (F344) rats exhibit proteinuria and insulin resistance in the absence of hypertension as they age. We determined the effects of long-term (1 yr) treatment with the angiotensin (ANG) II type 1 (AT(1)) receptor blocker L-158,809 on plasma and urinary ANG peptide levels, systolic blood pressure (SBP), and indexes of glucose metabolism in 15-mo-old male F344 rats. Young rats at 3 mo of age (n = 8) were compared with two separate groups of older rats: one control group (n = 7) and one group treated with L-158,809 (n = 6) orally (20 mg/l) for 1 yr. SBP was not different between control and treated rats but was higher in young rats. Serum leptin, insulin, and glucose levels were comparable between treated and young rats, whereas controls had higher glucose and leptin with a similar trend for insulin. Plasma ANG I and ANG II were higher in treated than untreated young or older rats, as evidence of effective AT(1) receptor blockade. Urinary ANG II and ANG-(1-7) were higher in controls compared with young animals, and treated rats failed to show age-related increases. Protein excretion was markedly lower in treated and young rats compared with control rats (young: 8 +/- 2 mg/day vs. control: 129 +/- 51 mg/day vs. treated: 9 +/- 3 mg/day, P < 0.05). Long-term AT(1) receptor blockade improves metabolic parameters and provides renoprotection. Differential regulation of systemic and intrarenal (urinary) ANG systems occurs during blockade, and suppression of the intrarenal system may contribute to reduced proteinuria. Thus, insulin resistance, renal injury, and activation of the intrarenal ANG system during early aging in normotensive animals can be averted by renin-ANG system blockade.
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Affiliation(s)
- Shea Gilliam-Davis
- The Hypertension and Vascular Disease Center, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1032, USA
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16
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Noland RC, Thyfault JP, Henes ST, Whitfield BR, Woodlief TL, Evans JR, Lust JA, Britton SL, Koch LG, Dudek RW, Dohm GL, Cortright RN, Lust RM. Artificial selection for high-capacity endurance running is protective against high-fat diet-induced insulin resistance. Am J Physiol Endocrinol Metab 2007; 293:E31-41. [PMID: 17341547 DOI: 10.1152/ajpendo.00500.2006] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Elevated oxidative capacity, such as occurs via endurance exercise training, is believed to protect against the development of obesity and diabetes. Rats bred both for low (LCR)- and high (HCR)-capacity endurance running provide a genetic model with inherent differences in aerobic capacity that allows for the testing of this supposition without the confounding effects of a training stimulus. The purpose of this investigation was to determine the effects of a high-fat diet (HFD) on weight gain patterns, insulin sensitivity, and fatty acid oxidative capacity in LCR and HCR male rats in the untrained state. Results indicate chow-fed LCR rats were heavier, hypertriglyceridemic, less insulin sensitive, and had lower skeletal muscle oxidative capacity compared with HCR rats. Upon exposure to an HFD, LCR rats gained more weight and fat mass, and their insulin resistant condition was exacerbated, despite consuming similar amounts of metabolizable energy as chow-fed controls. These metabolic variables remained unaltered in HCR rats. The HFD increased skeletal muscle oxidative capacity similarly in both strains, whereas hepatic oxidative capacity was diminished only in LCR rats. These results suggest that LCR rats are predisposed to obesity and that expansion of skeletal muscle oxidative capacity does not prevent excess weight gain or the exacerbation of insulin resistance on an HFD. Elevated basal skeletal muscle oxidative capacity and the ability to preserve liver oxidative capacity may protect HCR rats from HFD-induced obesity and insulin resistance.
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Affiliation(s)
- Robert C Noland
- Department of Physiology, East Carolina University, Greenville, North Carolina 27834, USA
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17
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Gordon ME, McKeever KH, Betros CL, Manso Filho HC. Exercise-induced alterations in plasma concentrations of ghrelin, adiponectin, leptin, glucose, insulin, and cortisol in horses. Vet J 2007; 173:532-40. [PMID: 16516509 DOI: 10.1016/j.tvjl.2006.01.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2006] [Indexed: 12/26/2022]
Abstract
Six Standardbred (STB) mares (11+/-2 years, 521+/-77 kg; means+/-SD) performed an exercise trial (EX) where they underwent an incremental exercise test (GXT) as well as a parallel control trial (CON) to test the hypothesis that short-term, high intensity exercise would alter plasma concentrations of glucose, leptin, adiponectin, ghrelin, insulin and cortisol. Plasma samples were taken before (0 min), during (last 10s at 6, 8m/s, and the velocity eliciting VO(2max)), and after exercise (2, 10, 30, 60 min; 12 and 24h post-GXT). A second set of blood samples was collected before and after an afternoon meal given at 1515 h (at 1500, 1514, 1530, and 1545 h). Data were analyzed using ANOVA for repeated measures and Tukey's test. During the GXT, there were no changes (P>0.05) in the plasma concentrations of glucose, leptin, adiponectin or ghrelin. However, there was a 29% increase (P<0.05) in mean plasma cortisol concentration and a 35% decrease (P<0.05) in mean plasma insulin concentration. Substantial increases (P<0.05) in the mean plasma concentrations of glucose and cortisol of 36% and 102%, respectively, were seen in the EX trial during the first 60 min post-GXT. Plasma leptin concentration, measured at the 24h post-GXT time point, was 20% lower (P<0.05) during the EX trial compared with the parallel time point in the standing control (CON) trial. Plasma ghrelin concentration was 37% lower (P<0.05) in the EX trial compared with CON before and after the afternoon meal, but was 43% higher (P<0.05) 12h post-GXT. There were no differences between EX and CON for plasma concentrations of insulin or adiponectin during recovery. It was concluded that short-term high intensity exercise alters plasma leptin and ghrelin concentrations in STB mares post-exercise, which may signal the exercised animals to alter energy intake.
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Affiliation(s)
- Mary E Gordon
- Equine Science Center, Department of Animal Sciences, Rutgers, The State University of New Jersey, 84 Lipman Drive, New Brunswick, NJ 08901-8525, USA
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18
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Gordon ME, McKeever KH. Oral and intravenous carbohydrate challenges decrease active ghrelin concentrations and alter hormones related to control of energy metabolism in horses1. J Anim Sci 2006; 84:1682-90. [PMID: 16775051 DOI: 10.2527/jas.2005-484] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This study tested the hypothesis that grain and intravenous dextrose challenges would alter plasma concentrations of active ghrelin, adiponectin, leptin, glucose, insulin, and cortisol in Standardbred mares. To deliver 0.5 g of glucose (dextrose solution for the intravenous test)/kg of BW, mares received intravenous dextrose (50% solution) or oral grain administration in 2 trials. In response to the oral grain challenge, plasma glucose and insulin concentrations increased (P < 0.001) by 56 and 802%, respectively. Plasma ghrelin concentration initially decreased (P < 0.001) by 40%, then subsequently increased (P < 0.05) from its nadir by 259%. Plasma leptin concentration decreased (P = 0.002) 17% compared with baseline. There was no change (P = 0.34) in plasma adiponectin concentration in response to oral grain challenge; however, plasma cortisol concentrations decreased (P < 0.001) by 24%. In response to the intravenous dextrose challenge, plasma glucose and insulin concentrations increased (P < 0.001) by 432 and 395%, respectively. Plasma active ghrelin concentration initially decreased (P < 0.001) by 56%, then subsequently increased (P < 0.001) from its nadir by 314%. Plasma leptin concentration also increased (P < 0.001) by 33% compared with baseline. There was no change (P = 0.18) in plasma adiponectin concentration throughout the dextrose challenge. Plasma cortisol concentration increased (P = 0.027) by 20%. Hence, oral grain and intravenous nutrient challenges have the ability to alter variables potentially related to energy metabolism in mares, with acute changes in glucose and insulin possibly modulating changes in ghrelin and leptin.
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Affiliation(s)
- M E Gordon
- Equine Science Center, Department of Animal Sciences, Rutgers, the State University of New Jersey, 84 Lipman Drive, New Brunswick 08901, USA
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19
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Kraegen EW, Saha AK, Preston E, Wilks D, Hoy AJ, Cooney GJ, Ruderman NB. Increased malonyl-CoA and diacylglycerol content and reduced AMPK activity accompany insulin resistance induced by glucose infusion in muscle and liver of rats. Am J Physiol Endocrinol Metab 2006; 290:E471-9. [PMID: 16234268 DOI: 10.1152/ajpendo.00316.2005] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glucose infusion in rats for 1-4 days results in insulin resistance and increased triglyceride, whole tissue long-chain fatty acyl-CoA (LCA-CoA), and malonyl-CoA content in red skeletal muscle. Despite this, the relation between these alterations and the onset of insulin resistance has not been defined. We aimed to 1) identify whether the changes in these lipids and of diacylglycerol (DAG) precede or accompany the onset of insulin resistance in glucose-infused rats, 2) determine whether the insulin resistance is associated with alterations in AMP-activated protein kinase (AMPK), and 3) assess whether similar changes occur in liver and in muscle. Hyperglycemia (17-18 mM) was maintained by intravenous glucose infusion in rats for 3 or 5 h; then euglycemia was restored and a 2-h hyperinsulinemic clamp was performed. Significant (P < 0.01) muscle and liver insulin resistance first appeared in red quadriceps and liver of the glucose-infused group at 5 h and was associated with a twofold increase in DAG and malonyl-CoA content and a 50% decrease in AMPK and acetyl-CoA carboxylase (ACC) phosphorylation and AMPK activity. White quadriceps showed qualitatively similar changes but without decreases in AMPK or ACC phosphorylation. Triglyceride mass was increased at 5 h only in liver, and whole tissue LCA-CoA content was not increased in liver or either muscle type. We conclude that the onset of insulin resistance induced by glucose oversupply correlates temporally with increases in malonyl-CoA and DAG content in all three tissues and with reduced AMPK phosphorylation and activity in red muscle and liver. In contrast, it was not associated with increased whole tissue LCA-CoA content in any tissue or triglyceride in muscle, although both are observed at later times.
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Affiliation(s)
- Edward W Kraegen
- Garvan Institute of Medical Research, Sydney NSW 2010 Australia.
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20
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Wade GN, Jones JE. Neuroendocrinology of nutritional infertility. Am J Physiol Regul Integr Comp Physiol 2005; 287:R1277-96. [PMID: 15528398 DOI: 10.1152/ajpregu.00475.2004] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Natural selection has linked the physiological controls of energy balance and fertility such that reproduction is deferred during lean times, particularly in female mammals. In this way, an energetically costly process is confined to periods when sufficient food is available to support pregnancy and lactation. Even in the face of abundance, nutritional infertility ensues if energy intake fails to keep pace with expenditure. A working hypothesis is proposed in which any activity or condition that limits the availability of oxidizable fuels (e.g., undereating, excessive energy expenditure, diabetes mellitus) can inhibit both gonadotropin-releasing hormone (GnRH)/luteinizing hormone secretion and female copulatory behaviors. Decreases in metabolic fuel availability appear to be detected by cells in the caudal hindbrain. Hindbrain neurons producing neuropeptide Y (NPY) and catecholamines (CA) then project to the forebrain where they contact GnRH neurons both directly and also indirectly via corticotropin-releasing hormone (CRH) neurons to inhibit GnRH secretion. In the case of estrous behavior, the best available evidence suggests that the inhibitory NPY/CA system acts primarily via CRH or urocortin projections to various forebrain loci that control sexual receptivity. Disruption of these signaling processes allows normal reproduction to proceed in the face of energetic deficits, indicating that the circuitry responds to energy deficits and that no signal is necessary to indicate that there is an adequate energy supply. While there is a large body of evidence to support this hypothesis, the data do not exclude nutritional inhibition of reproduction by other pathways and processes, and the full story will undoubtedly be more complex than this.
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Affiliation(s)
- George N Wade
- Center for Neuroendocrine Studies, University of Massachusetts, 135 Hicks Way, Amherst, MA 01003, USA.
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21
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Walker CG, Bryson JM, Bell-Anderson KS, Hancock DP, Denyer GS, Caterson ID. Insulin determines leptin responses during a glucose challenge in fed and fasted rats. Int J Obes (Lond) 2005; 29:398-405. [PMID: 15672109 DOI: 10.1038/sj.ijo.0802884] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Leptin secretion has been shown to respond acutely to changes in blood glucose and insulin. Nutritional state also has a marked effect on both the level of circulating leptin protein and leptin gene expression. The aim of this study was to assess whether the prior nutritional state altered the leptin secretory response to an acute glucose challenge, and to determine potential mechanisms. DESIGN Male fed or fasted rats (200-250 g) were administered a single intravenous glucose bolus (1, 4 or 7 g/kg). The serum leptin, glucose, insulin and free fatty acid responses were studied over the following 5 h. The level of leptin gene expression and leptin protein was then determined in the epididymal fat pads, and in fed and fasted untreated rats for basal comparison. RESULTS Leptin secretion in response to glucose was suppressed in fasted rats following all glucose doses. The total leptin response was correlated with the total insulin response in all conditions (r = 0.85) and with the glucose response in fed rats (r = 0.69). Both leptin gene expression and leptin protein content were lower in basal fasted rats. Leptin gene expression and leptin protein content still remained lower 5 h following a glucose bolus but there was partial reversal of the effects of fasting following the 7 g/kg glucose dose. CONCLUSIONS Leptin secretion in response to an intravenous glucose bolus was determined by the insulin response and was significantly suppressed in fasted compared to fed rats. In addition to differences in the total insulin response of the animals, lower leptin responses may be facilitated by lower levels of both leptin gene mRNA and pre-existing leptin protein in epididymal adipose tissue of fasted rats.
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Affiliation(s)
- C G Walker
- Human Nutrition Unit, University of Sydney, NSW, Australia.
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22
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Levy JR, Stevens W. Plasma hyperosmolality stimulates leptin secretion acutely by a vasopressin-adrenal mechanism. Am J Physiol Endocrinol Metab 2004; 287:E263-8. [PMID: 15068959 DOI: 10.1152/ajpendo.00514.2003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glucose administration to rodents acutely stimulates leptin secretion. To investigate the mechanism, rats were infused intravenously with various concentrations of glucose, and plasma leptin concentrations were measured with time. The osmolality of the infusates was equalized with various concentrations of carbohydrates that are not metabolized. Hyperosmolar glucose stimulates leptin secretion in a dose-dependent manner, with peak plasma leptin concentrations occurring approximately 3 h after the end of the glucose infusion. Hypertonic infusions of galactose, mannitol, and sodium chloride independently stimulate leptin secretion with approximately one-half the strength of equivalent osmolar concentrations of glucose. Peak plasma leptin concentrations occur approximately 4 h after the end of the hypertonic solution infusion. Hypertonic solutions of mannitol do not stimulate leptin secretion in vasopressin-deficient or in adrenalectomized animals. In conclusion, intravenous infusions of hypertonic glucose and hypertonic mannitol independently stimulate leptin secretion. Hyperosmolality stimulates leptin secretion by a vasopressin-adrenal mechanism.
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Affiliation(s)
- James R Levy
- Section of Endocrinology and Metabolism, McGuire Veterans Administration Medical Center, Richmond, Virginia 23249, USA.
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23
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Levy JR, Clore JN, Stevens W. Dietary n-3 polyunsaturated fatty acids decrease hepatic triglycerides in Fischer 344 rats. Hepatology 2004; 39:608-16. [PMID: 14999679 DOI: 10.1002/hep.20093] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dietary fatty acid composition modifies hepatic lipid metabolism. To determine the effects of fatty acids on hepatic triglyceride storage, rats were fed diets enriched in carbohydrates (control), fish oil, or lard. After 4 weeks, the animals were fasted overnight. In the morning, the animals were either sacrificed or fed 8 g of their respective diets before sacrifice. Animals ingested more food calories with diets containing fish oil than with other diets. However, fish oil-fed animals weighed less and had less body fat. In fish oil-fed animals, liver triglyceride was lower by 27% (P <.05) and 73% (P <.01) than in control- and lard-fed animals, respectively. Fish oil altered the postprandial gene expression of hepatic regulators of fatty acid degradation and synthesis. Fish oil feeding blunted the normal postprandial decline in fatty acid degradation genes (PPARalpha, CPT1, and ACO) and blunted the normal postprandial rise in triglyceride synthesis genes (SREBP1-c, FAS, SCD-1). Therefore, the direct postprandial effect of fish oil ingestion decreases the propensity for hepatic triglyceride storage. In conclusion, n-3 polyunsaturated fatty acids decrease total body weight, total body fat, and hepatic steatosis.
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Affiliation(s)
- James R Levy
- Section of Endocrinology and Metabolism, McGuire Veterans Administration Medical Center 111-P, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA.
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24
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Steinberg GR, Smith AC, Wormald S, Malenfant P, Collier C, Dyck DJ. Endurance training partially reverses dietary-induced leptin resistance in rodent skeletal muscle. Am J Physiol Endocrinol Metab 2004; 286:E57-63. [PMID: 14662513 DOI: 10.1152/ajpendo.00302.2003] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leptin acutely stimulates skeletal muscle fatty acid (FA) metabolism in lean rodents and humans. This stimulatory effect is eliminated following the feeding of high-fat diets in rodents as well as in obese humans. The mechanism(s) responsible for the development of skeletal muscle leptin resistance is unknown; however, a role for increased suppressor of cytokine signaling-3 (SOCS3) inhibition of the leptin receptor has been demonstrated in other rodent tissues. Furthermore, whether exercise intervention is an effective strategy to prevent or attenuate the development of skeletal muscle leptin resistance has not been investigated. Toward this end, 48 Sprague-Dawley rats (175-190 g; approximately 2-3 mo of age) were fed control or high-fat (60% kcal) diets for 4 wk and either remained sedentary or were treadmill trained. In control diet-fed animals that remained sedentary (CS) or were endurance trained (CT), leptin stimulated FA oxidation (CS +32 +/- 15%, CT +30 +/- 17%; P < 0.05), suppressed triacylglycerol (TAG) esterification (CS -17 +/- 7%, CT -24 +/- 8%; P < 0.05), and reduced the esterification-to-oxidation ratio (CS -19 +/- 13%, CT -29 +/- 10%; P < 0.001) in soleus muscle. High-fat feeding induced leptin resistance in the soleus of sedentary rats (FS), whereas endurance exercise training (FT) restored the ability of leptin to suppress TAG esterification (-19 +/- 9%, P = 0.038). Training did not completely restore the ability of leptin to stimulate FA oxidation. High-fat diets stimulated SOCS3 mRNA expression irrespective of training status (FS +451 +/- 120%, P = 0.024; FT +381 +/- 141%, P = 0.023). Thus the development of skeletal muscle leptin resistance appears to involve an increase in SOCS3 mRNA expression. Endurance training was generally effective in preventing the development of leptin resistance, although this did not appear to require a decrease in SOCS3 expression. Future studies should examine changes in the actual protein content of SOCS3 in muscle and establish whether aerobic exercise is also effective in treating leptin resistance in humans.
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Affiliation(s)
- Gregory R Steinberg
- Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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25
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Chelikani PK, Keisler DH, Kennelly JJ. Response of Plasma Leptin Concentration to Jugular Infusion of Glucose or Lipid Is Dependent on the Stage of Lactation of Holstein Cows. J Nutr 2003; 133:4163-71. [PMID: 14652366 DOI: 10.1093/jn/133.12.4163] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study we investigated the hormonal and metabolite responses to isoenergetic jugular infusions of glucose or lipid in early- and late-lactation Holstein cows. Six Holstein cows were used in a replicated Latin square design with jugular infusions of either 1) control (CON; saline), 2) glucose (GLU; 50% dextrose) or 3) lipid (LIP; 20% Intralipid). Treatments did not affect dry matter intake, with the exception of a hypophagic effect of LIP in late lactation. The GLU-induced hyperglycemia and hyperinsulinemia were greater in late-lactation than in early-lactation cows. The GLU treatment did not affect plasma leptin and insulin-like growth factor-1 (IGF-1) concentrations in early-lactation cows, but it increased them in late-lactation cows. The LIP treatment did not affect plasma leptin, insulin and IGF-1 concentrations in early-lactation cows, despite a marked LIP-induced increase in plasma nonesterified fatty acid and beta-hydroxybutyrate concentrations and a reduction in growth hormone (GH) concentration. Compared with the delayed leptin response to GLU, the stimulatory effect of LIP on leptin secretion in late-lactation cows was relatively rapid and occurred in the absence of any significant changes in plasma insulin, IGF-1 or GH. We propose that insulin-mediated glucose metabolism may be involved in the stimulatory effects of glucose on leptin secretion in late-lactation animals but that the stimulatory effects of lipid are independent of insulin or IGF-1. In early-lactation animals a strong inhibitory effect of GH on leptin expression and release, in addition to low adipose reserves and/or energy balance, might override any short-term stimulatory effect of glucose or lipid on leptin secretion.
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Affiliation(s)
- Prasanth K Chelikani
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5
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26
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Pérez-Matute P, Marti A, Martínez JA, Moreno-Aliaga MJ. Effects of arachidonic acid on leptin secretion and expression in primary cultured rat adipocytes. J Physiol Biochem 2003; 59:201-8. [PMID: 15000451 DOI: 10.1007/bf03179916] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Leptin, a hormone produced in adipocytes, is a key signal in the regulation of food intake and energy expenditure. Several studies have suggested that leptin can be regulated by macronutrients intake. Arachidonic acid is a dietary fatty acid known to affect cell metabolism. Controversial effects of this fatty acid on leptin have been reported. The aim of this experimental trial was to evaluate the effect of the arachidonic acid on basal and insulin-stimulated leptin secretion and expression in isolated rat adipocytes. Because insulin-stimulated glucose metabolism is an important regulator of leptin expression and secretion by the adipocytes, the effects of the arachidonic acid on indices of adipocyte metabolism were also examined. Isolated adipocytes were incubated with arachidonic acid (1-200 microM) in the absence and presence of insulin (1.6 nM). Leptin secretion and expression, glucose utilization and lactate production were determined at 96 h. The arachidonic acid (200 microM) inhibited both the basal and insulin stimulated leptin secretion and expression. Glucose utilization was not affected by the acid. Basal lactate production was increased by the fatty acid at the highest concentration used (200 microM), however lactate production in presence of insulin was not modified. Finally, the percentage of glucose carbon released as lactate was significantly increased (200 microM). These results suggest that the inhibitory effect of the arachidonic acid on leptin secretion and expression may be due, al least in part, to the increase in the anaerobic utilization of glucose.
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Affiliation(s)
- P Pérez-Matute
- Department of Physiology and Nutrition, University of Navarra, 31008 Pamplona, Spain
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27
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Puchalski SS, Green JN, Rasmussen DD. Melatonin effect on rat body weight regulation in response to high-fat diet at middle age. Endocrine 2003; 21:163-7. [PMID: 12897381 DOI: 10.1385/endo:21:2:163] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2003] [Revised: 03/05/2003] [Accepted: 03/05/2003] [Indexed: 11/11/2022]
Abstract
We previously demonstrated that daily melatonin administration to middle-aged rats to restore youthful plasma melatonin levels also decreased body weight, visceral fat, plasma leptin, and plasma insulin to more youthful levels, without detectable changes in consumption of chow diet. We now evaluate: (a) whether melatonin alters consumption of a more precisely quantifiable liquid diet similar in high-fat content to the typical American diet; (b) differences between melatonin-induced endocrine responses in the fasted vs fed state; and (c) time course of these responses. Ten-month-old male Sprague- Dawley rats received liquid diet containing either 0.2 micro g/mL melatonin (MELATONIN) or vehicle (CONTROL) (n = 14/treatment); the diet was available throughout each night, but was removed for the final 10 h of each daytime. MELATONIN rats gained 4% body weight during the first 2 wk and then stabilized, whereas CONTROL rats continued to gain for an additional week, achieving 8% gain (p < 0.05 vs MELATONIN). During the first 3 wk, afternoon tail-blood leptin, but not insulin, levels decreased in melatonin-treated rats (p < 0.05 vs CONTROL). After 8 wk, half of the rats were killed at the midpoint of the dark period (NIGHT; fed) and half at the end of the light period (DAYTIME; fasted). NIGHT but not DAYTIME plasma leptin levels were decreased in MELATONIN rats, whereas DAYTIME but not NIGHT plasma insulin levels were decreased (p < 0.05 vs CONTROL). Melatonin treatment did not alter cumulative food consumption. Thus, melatonin decreased weight gain in response to high-fat diet, decreased plasma leptin levels within 3 wk-before decreasing plasma insulin-and exerted these metabolic effects independent of total food consumption.
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Affiliation(s)
- Stephaney S Puchalski
- VA Puget Sound Health Care System Mental Illness Research, Education and Clinical Center (MIRECC) and Department of Psychiatry, University of Washington, Seattle, WA 98108, USA.
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Brown JL, Spicer MT, Spicer LJ. Effect of high-fat diet on body composition and hormone responses to glucose tolerance tests. Endocrine 2002; 19:327-32. [PMID: 12624434 DOI: 10.1385/endo:19:3:327] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2002] [Revised: 11/13/2002] [Accepted: 11/13/2002] [Indexed: 11/11/2022]
Abstract
To determine potential hormonal mediators of the effect of high-fat diets on the development of insulin resistance, blood leptin, growth hormone (GH), glucose, and insulin responses to a 2 g/kg BW oral glucose challenge were evaluated in weanling female Sprague Dawley rats that were randomly assigned to a high-fat (HF, 39% of calories, 20% fat by weight; n = 10) and moderate-fat (MF, 22% of calories, 10% fat by weight; n = 10) diets. Oral glucose challenges were administered following 5, 7, and 9 wk on the feeding trial. Animals were provided diet in excess of their requirements for growth. Body mass analysis was conducted by dual X-ray absorptiometry (DXA) on the 6th, 8th, and 10th weeks of the trial. HF animals gained more weight after 7 wk, had greater body fat than the MF animals, and similar glucose responses to the oral glucose challenges. HF rats secreted more insulin and leptin compared to MF animals. Lean body mass and serum GH and IGF-I concentrations were not different between the groups. Results of this study demonstrate that leptin but not GH or IGF-I is involved in the development of insulin resistance in growing rats as a result of excess energy intake in the form of dietary fat.
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Affiliation(s)
- J L Brown
- Department of Nutritional Sciences, Oklahoma State University, Stillwater 74078, USA
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Levy JR, Davenport B, Clore JN, Stevens W. Lipid metabolism and resistin gene expression in insulin-resistant Fischer 344 rats. Am J Physiol Endocrinol Metab 2002; 282:E626-33. [PMID: 11832366 DOI: 10.1152/ajpendo.00346.2001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interrelationship between insulin and leptin resistance in young Fischer 344 (F344) rats was studied. Young F344 and Sprague-Dawley (SD) rats were fed regular chow. F344 animals had two- to threefold higher insulin and triglyceride concentrations and increased stores of triglycerides within liver and muscle. F344 animals gained more body fat. Both acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase I gene expression were 20-50% less in F344 animals than in age-matched SD animals. Peroxisome proliferator-activated receptor-alpha gene expression was reduced in 70-day-old F344 animals. Finally, resistin gene expression was similar in 70-day-old SD and F344 animals. Resistin gene expression increased fivefold in F344 animals and twofold in SD animals from 70 to 130 days, without a change in insulin sensitivity. We conclude that young F344 animals have both insulin and leptin resistance, which may lead to diminished fatty oxidation and accumulation of triglycerides in insulin-sensitive target tissues. We did not detect a role for resistin in the etiology of insulin resistance in F344 animals.
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Affiliation(s)
- James R Levy
- Section of Endocrinology and Metabolism, McGuire Veterans Administration Medical Center, Richmond, Virginia 23249, USA.
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