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Winn NC, Acin-Perez R, Woodford ML, Hansen SA, Haney MM, Ayedun LA, Rector RS, Vieira-Potter VJ, Shirihai OS, Sacks HS, Kanaley JA, Padilla J. A Thermogenic-Like Brown Adipose Tissue Phenotype Is Dispensable for Enhanced Glucose Tolerance in Female Mice. Diabetes 2019; 68:1717-1729. [PMID: 30862679 PMCID: PMC6702635 DOI: 10.2337/db18-1070] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 03/04/2019] [Indexed: 12/12/2022]
Abstract
The prevailing dogma is that thermogenic brown adipose tissue (BAT) contributes to improvements in glucose homeostasis in obesogenic animal models, though much of the evidence supporting this premise is from thermostressed rodents. Determination of whether modulation of the BAT morphology/function drives changes in glucoregulation at thermoneutrality requires further investigation. We used loss- and gain-of-function approaches including genetic manipulation of the lipolytic enzyme Pnpla2, change in environmental temperature, and lifestyle interventions to comprehensively test the premise that a thermogenic-like BAT phenotype is coupled with enhanced glucose tolerance in female mice. In contrast to this hypothesis, we found that 1) compared to mice living at thermoneutrality, enhanced activation of BAT and its thermogenic phenotype via chronic mild cold stress does not improve glucose tolerance in obese mice, 2) silencing of the Pnpla2 in interscapular BAT causes a brown-to-white phenotypic shift accompanied with inflammation but does not disrupt glucose tolerance in lean mice, and 3) exercise and low-fat diet improve glucose tolerance in obese mice but these effects do not track with a thermogenic BAT phenotype. Collectively, these findings indicate that a thermogenic-like BAT phenotype is not linked to heightened glucose tolerance in female mice.
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Affiliation(s)
- Nathan C Winn
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Rebeca Acin-Perez
- Division of Endocrinology, Department of Medicine, and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | | | - Sarah A Hansen
- Office of Animal Resources, University of Missouri, Columbia, MO
| | - Megan M Haney
- Office of Animal Resources, University of Missouri, Columbia, MO
| | - Lolade A Ayedun
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
| | - R Scott Rector
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, MO
- Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | | | - Orian S Shirihai
- Division of Endocrinology, Department of Medicine, and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Harold S Sacks
- Division of Endocrinology, Department of Medicine, and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Jill A Kanaley
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
| | - Jaume Padilla
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
- Child Health, University of Missouri, Columbia, MO
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2
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Su Y, Foppen E, Fliers E, Kalsbeek A. Effects of Intracerebroventricular Administration of Neuropeptide Y on Metabolic Gene Expression and Energy Metabolism in Male Rats. Endocrinology 2016; 157:3070-85. [PMID: 27267712 DOI: 10.1210/en.2016-1083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Neuropeptide Y (NPY) is an important neurotransmitter in the control of energy metabolism. Several studies have shown that obesity is associated with increased levels of NPY in the hypothalamus. We hypothesized that the central release of NPY has coordinated and integrated effects on energy metabolism in different tissues, resulting in increased energy storage and decreased energy expenditure (EE). We first investigated the acute effects of an intracerebroventricular (ICV) infusion of NPY on gene expression in liver, brown adipose tissue, soleus muscle, and sc and epididymal white adipose tissue (WAT). We found increased expression of genes involved in gluconeogenesis and triglyceride secretion in the liver already 2-hour after the start of the NPY administration. In brown adipose tissue, the expression of thermogenic genes was decreased. In sc WAT, the expression of genes involved in lipogenesis was increased, whereas in soleus muscle, the expression of lipolytic genes was decreased after ICV NPY. These findings indicate that the ICV infusion of NPY acutely and simultaneously increases lipogenesis and decreases lipolysis in different tissues. Subsequently, we investigated the acute effects of ICV NPY on locomotor activity, respiratory exchange ratio, EE, and body temperature. The ICV infusion of NPY increased locomotor activity, body temperature, and EE as well as respiratory exchange ratio. Together, these results show that an acutely increased central availability of NPY results in a shift of metabolism towards lipid storage and an increased use of carbohydrates, while at the same time increasing activity, EE, and body temperature.
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Affiliation(s)
- Yan Su
- Hypothalamic Integration Mechanisms (Y.S., A.K.), Netherlands Institute for Neuroscience, 1105 BA Amsterdam, The Netherlands; and Department of Endocrinology and Metabolism (E.Fo.,E.Fl., A.K.), Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Ewout Foppen
- Hypothalamic Integration Mechanisms (Y.S., A.K.), Netherlands Institute for Neuroscience, 1105 BA Amsterdam, The Netherlands; and Department of Endocrinology and Metabolism (E.Fo.,E.Fl., A.K.), Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Eric Fliers
- Hypothalamic Integration Mechanisms (Y.S., A.K.), Netherlands Institute for Neuroscience, 1105 BA Amsterdam, The Netherlands; and Department of Endocrinology and Metabolism (E.Fo.,E.Fl., A.K.), Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Andries Kalsbeek
- Hypothalamic Integration Mechanisms (Y.S., A.K.), Netherlands Institute for Neuroscience, 1105 BA Amsterdam, The Netherlands; and Department of Endocrinology and Metabolism (E.Fo.,E.Fl., A.K.), Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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3
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Yew Tan C, Virtue S, Murfitt S, Roberts LD, Robert LD, Phua YH, Dale M, Griffin JL, Tinahones F, Scherer PE, Vidal-Puig A. Adipose tissue fatty acid chain length and mono-unsaturation increases with obesity and insulin resistance. Sci Rep 2015; 5:18366. [PMID: 26679101 PMCID: PMC4683622 DOI: 10.1038/srep18366] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/16/2015] [Indexed: 11/09/2022] Open
Abstract
The non-essential fatty acids, C18:1n9, C16:0, C16:1n7, C18:0 and C18:1n7 account for over 75% of fatty acids in white adipose (WAT) triacylglycerol (TAG). The relative composition of these fatty acids (FA) is influenced by the desaturases, SCD1-4 and the elongase, ELOVL6. In knock-out models, loss of SCD1 or ELOVL6 results in reduced Δ9 desaturated and reduced 18-carbon non-essential FA respectively. Both Elovl6 KO and SCD1 KO mice exhibit improved insulin sensitivity. Here we describe the relationship between WAT TAG composition in obese mouse models and obese humans stratified for insulin resistance. In mouse models with increasing obesity and insulin resistance, there was an increase in scWAT Δ9 desaturated FAs (SCD ratio) and FAs with 18-carbons (Elovl6 ratio) in mice. Data from mouse models discordant for obesity and insulin resistance (AKT2 KO, Adiponectin aP2-transgenic), suggested that scWAT TAG Elovl6 ratio was associated with insulin sensitivity, whereas SCD1 ratio was associated with fat mass. In humans, a greater SCD1 and Elovl6 ratio was found in metabolically more harmful visceral adipose tissue when compared to subcutaneous adipose tissue.
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Affiliation(s)
- Chong Yew Tan
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC. Addenbrooke's Hospital, Cambridge, CB2 0QQ
| | - Samuel Virtue
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC. Addenbrooke's Hospital, Cambridge, CB2 0QQ
| | - Steven Murfitt
- University of Cambridge Department of Biochemistry, 80 Tennis Court Road, Cambridge, CB2 1GA
| | | | - Lee D Robert
- University of Cambridge Department of Biochemistry, 80 Tennis Court Road, Cambridge, CB2 1GA.,Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, Uk
| | - Yi Hui Phua
- University of Cambridge Department of Biochemistry, 80 Tennis Court Road, Cambridge, CB2 1GA
| | - Martin Dale
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC. Addenbrooke's Hospital, Cambridge, CB2 0QQ
| | - Julian L Griffin
- University of Cambridge Department of Biochemistry, 80 Tennis Court Road, Cambridge, CB2 1GA.,Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, Uk
| | - Francisco Tinahones
- UGC Endocrinologia y Nutrición (IBIMA), Hospital Virgen de la Victoria. CIBER of Physiopathology, Obesity and Nutrition (CIBEROBN) Málaga, Spain
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Antonio Vidal-Puig
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC. Addenbrooke's Hospital, Cambridge, CB2 0QQ.,Wellcome Trust Sanger Institute, Hinxton, Uk
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4
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Balbo SL, Grassiolli S, Ribeiro RA, Bonfleur ML, Gravena C, Brito MDN, Andreazzi AE, Mathias PCDF, Torrezan R. Fat storage is partially dependent on vagal activity and insulin secretion of hypothalamic obese rat. Endocrine 2007; 31:142-8. [PMID: 17873325 DOI: 10.1007/s12020-007-0021-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 05/07/2007] [Accepted: 05/14/2007] [Indexed: 10/23/2022]
Abstract
Hypothalamic MSG-obese rats show hyperinsulinemia and tissue insulin resistance, and they display intense parasympathetic activity. Current analysis investigates whether early subdiaphragmatic vagotomy prevents tissue insulin sensitivity impairment in adult obese MSG-rats. Hypothalamic obesity was induced by MSG (4 mg/g BW), daily, from birth up to 5 days. Control animals receiving saline solution. On the 30th day rats underwent bilateral subdiaphragmatic vagotomy or sham surgery. An intravenous glucose tolerance test (i.v.GTT) was performed when rats turned 90 days old. Total white fat tissue (WAT) from rat carcass was extracted and isolated; the interscapular brown fat tissue (IBAT) was weighed. Rather than blocking obesity, vagotomy reduced WAT and IBAT in MSG-obese rats when the latter were compared to sham MSG-rats. High blood fasting insulin and normal glucose levels were also observed in MSG-obese rats. Although glucose intolerance, high insulin secretion, and significant insulin resistance were recorded, vagotomy improved fasting insulinemia, glucose tolerance and insulin tissue sensitivity in MSG-obese rats. Results suggest that increased fat accumulation is caused, at least in part, by high blood insulin concentration, and enhanced parasympathetic activity on MSG-obese rats.
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Affiliation(s)
- Sandra Lucinei Balbo
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Avenida Colombo 5790, Maringa, PR, 87020-900, Brazil
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5
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Naruta E, Buko V. Hypolipidemic effect of pantothenic acid derivatives in mice with hypothalamic obesity induced by aurothioglucose. EXPERIMENTAL AND TOXICOLOGIC PATHOLOGY : OFFICIAL JOURNAL OF THE GESELLSCHAFT FUR TOXIKOLOGISCHE PATHOLOGIE 2001; 53:393-8. [PMID: 11817109 DOI: 10.1078/0940-2993-00205] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The hypolipidemic effects of pantothenic acid derivatives (phosphopantothenate, panthenol and pantethine) were studied in mice with hypothalamic obesity. Hypothalamic obesity in mice was induced by single injection of aurothioglucose (300 mg/kg body wt, i.p.). All the tested substances were administered during the last 10 days before decapitation (i.m., of dosage equivalent to 150 mg/kg body wt of phosphopantothenate). The studied substances inhibited the weight gain of the animals with hypothalamic obesity over the last 10 days of the experiment. The treatment with aurothioglucose increased food intake and mean body weight, blood glucose level; insulin, serum total cholesterol, triglyceride, the sum of LDL + VLDL and LDL-cholesterol concentration; triglyceride and cholesterol fractions in the liver; triglyceride and FFA content as well as lipoprotein lipase activity in adipose tissue of experimental mice. The administration of the assay compounds lowered food intake and mean body weight, insulin and glucose levels and decreased the content of triglycerides, total cholesterol and cholesterol esters in serum and adipose tissue as well as raised the activity of lipoprotein lipase in adipose tissue and serum lipolytic activity in obese mice. Among the compounds studied the reverse effect of panthenol was especially pronounced. The mechanism of hypolipidemic effects of pantothenic acid derivatives can be related to the reduced resistance to insulin and activation of lipolysis in serum and adipose tissue.
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Affiliation(s)
- E Naruta
- Department of Experimental Hepathology, Institute of Biochemistry, National Academy of Sciences, Grodno, Belarus
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6
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Jansen GR. A comparison of extrahepatic lipogenesis from a small glucose meal in obob and gold thioglucose obese mice fed low- or high-fat diets with or without the addition of Delta22-5beta-taurocholenic acid. J Nutr Biochem 2000; 11:87-93. [PMID: 10715593 DOI: 10.1016/s0955-2863(99)00081-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Extrahepatic fatty acid synthesis from a 250 mg meal of [U-(14)C]-glucose was measured in epidymal fat pads and the remaining carcass of hyperglycemic obese (obob), gold thioglucose obese, and nonobese controls under conditions of maximum and minimum lipogenesis. Also assessed was the effect of Delta(22)-5beta-taurocholenic acid, previously shown to inhibit hepatic fatty acid synthesis. Both types of obese and nonobese mice were fed for 6 weeks glucose-based diets containing either 1% corn oil or 40% lard with or without the addition of 0.05% taurocholenic acid. In mice fed 1% corn oil, incorporation of labeled glucose into carcass fatty acids was 25% greater in nonobese than obese mice of either type of obesity. On this diet incorporation of labeled glucose into epididymal fatty acids was reduced 83% in hyperglycemic obese mice compared with nonobese littermates. The corresponding reduction in lipogenesis in gold thioglucose obese mice was only 23% compared with nonobese controls. Feeding 40% lard reduced incorporation of labeled glucose into epididymal and carcass fatty acid 67 to 95% compared with mice fed 1% corn oil in both types of obese and nonobese mice whether or not taurocholenic acid had been fed. Both types of obesity or feeding 40% lard reduced lipogenesis in fat pads to a greater extent than glucose uptake by the pads with the reductions additive. Feeding taurocholenic acid reduced pad weight 30% across strain and obesity status, increased uptake of labeled glucose into epididymal fat pads and increased the percentage of the labeled glucose in the pad recovered as fatty acid in both types of obese and nonobese mice when the diet was 1% corn oil. Similarities and differences between the two obesity models are discussed.
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Affiliation(s)
- G R Jansen
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO 80523, USA
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7
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Bryson JM, Phuyal JL, Swan V, Caterson ID. Leptin has acute effects on glucose and lipid metabolism in both lean and gold thioglucose-obese mice. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:E417-22. [PMID: 10484352 DOI: 10.1152/ajpendo.1999.277.3.e417] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leptin is reported to have effects in peripheral tissues that are independent of its central effects on food intake and body weight. In this study, the acute effects of a single dose of recombinant mouse leptin on lipid and glucose metabolism in lean and gold thioglucose-injected obese mice were examined. Changes were measured 2 h after leptin injection. In lean mice, liver and white adipose tissue (WAT) lipogenesis was inhibited. The activity of the pyruvate dehydrogenase complex (PDHCa), the rate-determining step for glucose oxidation, was reduced in heart, liver, quadriceps muscle, and both brown and white adipose tissues. Muscle and liver glycogen and liver triglyceride (TG) content was unchanged, but muscle TG was decreased. In obese mice, liver and WAT lipogenesis was inhibited and PDHCa reduced in heart and quadriceps muscle. Muscle and liver glycogen was decreased but not TG. Serum insulin was reduced in obese but not lean mice. These results are consistent with a role for leptin in the maintenance of steady-state energy stores by decreasing lipid synthesis and increasing fat mobilization, with decreased glucose oxidation occurring as a result of increased fatty acid oxidation.
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Affiliation(s)
- J M Bryson
- Human Nutrition Unit, Department of Biochemistry, University of Sydney, Sydney, New South Wales 2006, Australia.
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8
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Lewandowski PA, Cameron-Smith D, Jackson CJ, Kultys ER, Collier GR. The role of lipogenesis in the development of obesity and diabetes in Israeli sand rats (Psammomys obesus). J Nutr 1998; 128:1984-8. [PMID: 9808653 DOI: 10.1093/jn/128.11.1984] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Obesity and diabetes in Israeli sand rats, Psammomys obesus, occur with the sequential transition of animals from normal insulin sensitivity to impaired insulin sensitivity, accompanied by increased adiposity, prior to insulin resistance and obesity, in a manner similar to susceptible human populations. The current study was designed to examine the role of de novo lipid synthesis in the development of excessive weight gain in P. obesus. Sand rats were classified at 12 wk of age into three groups: A, normoglycemic normoinsulinemic; B, normoglycemic hyperinsulinemic; C, hyperglycemic hyperinsulinemic, based on glucose and insulin responses in fed sand rats. Body weight, liver weight, white adipose tissue (WAT) mass and food intake were significantly elevated in Group C compared to Group A (P < 0.05). Lipogenic rate was measured by the amount of 3H incorporated into subscapular brown adipose tissue (BAT), epidiymal WAT and liver per hour, from sand rats with and without access to food. No difference in lipogenic rate was found between the groups in BAT, indicating that this tissue is of minor importance in whole body lipogenesis in P. obesus. In the WAT there was a greater lipogenic rate with the development of obesity and hyperinsulinemia (Group B vs. Group A) but no difference in the liver. However, the onset of hyperglycemia (Group C) further stimulated WAT lipogenesis and initiated increased hepatic lipogenesis, both of which contributed to the pre-existing obesity. This study suggests that elevated lipogenesis is not the primary cause of obesity in P. obesus, as lipogenic rate only markedly increases after obesity is already present in hyperglycemic animals.
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Affiliation(s)
- P A Lewandowski
- School of Nutrition and Public Health, Deakin University, Geelong, Victoria 3217, Australia
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9
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Kulkarni RN, Wang ZL, Wang RM, Hurley JD, Smith DM, Ghatei MA, Withers DJ, Gardiner JV, Bailey CJ, Bloom SR. Leptin rapidly suppresses insulin release from insulinoma cells, rat and human islets and, in vivo, in mice. J Clin Invest 1997; 100:2729-36. [PMID: 9389736 PMCID: PMC508476 DOI: 10.1172/jci119818] [Citation(s) in RCA: 208] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Obesity is associated with diabetes, and leptin is known to be elevated in obesity. To investigate whether leptin has a direct effect on insulin secretion, isolated rat and human islets and cultured insulinoma cells were studied. In all cases, mouse leptin inhibited insulin secretion at concentrations within the plasma range reported in humans. Insulin mRNA expression was also suppressed in the cultured cells and rat islets. The long form of the leptin receptor (OB-Rb) mRNA was present in the islets and insulinoma cell lines. To determine the significance of these findings in vivo, normal fed mice were injected with two doses of leptin. A significant decrease in plasma insulin and associated rise in glucose concentration were observed. Fasted normal and leptin receptor-deficient db/db mice showed no response to leptin. A dose of leptin, which mimicked that found in normal mice, was administered to leptin-deficient, hyperinsulinemic ob/ob mice. This caused a marked lowering of plasma insulin concentration and a doubling of plasma glucose. Thus, leptin has a powerful acute inhibitory effect on insulin secretion. These results suggest that the action of leptin may be one mechanism by which excess adipose tissue could acutely impair carbohydrate metabolism.
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Affiliation(s)
- R N Kulkarni
- Division of Endocrinology, Department of Metabolic Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London W12 0NN, United Kingdom
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10
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Routh VH, Stern JS, Horwitz BA. Physiological Responses of Mammals to Overnutrition. Compr Physiol 1996. [DOI: 10.1002/cphy.cp040262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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11
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Bryson JM, Cooney GJ, Wensley VR, Phuyal JL, Caterson ID. Tissue differences in the response of the pyruvate dehydrogenase complex to a glucose load during the development of obesity in gold-thioglucose-obese mice. Biochem J 1995; 305 ( Pt 3):811-6. [PMID: 7848280 PMCID: PMC1136331 DOI: 10.1042/bj3050811] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The activity of pyruvate dehydrogenase (PDHC), a key enzyme complex in the oxidative disposal of glucose, was measured after an oral glucose load in the heart, liver, quadriceps muscle, white adipose tissue (WAT) and brown adipose tissue (BAT) of gold-thioglucose (GTG)-obese mice at different stages during the development of obesity and in age-matched controls. Significant responses to the glucose load were seen 30 min post-gavage in heart, WAT and BAT of control mice but no change was observed in quadriceps muscle. The increase in activity of the active form of PDHC (PDHCa) in response to glucose in heart was reduced 2 weeks after the induction of GTG-obesity with no response in 5 or 10 week obese mice. A 2-3-fold increase in the PDHCa response in both WAT and BAT of 2 week obese mice was absent in 5 and 10 week obese animals. Basal PDHCa activity in quadriceps muscle was increased in 2 week obese mice but subsequently returned to control levels as obesity progressed. The glucose load produced no change in the activity of PDHCa in quadriceps muscle of obese mice. These results demonstrate that changes in the capacity for oxidative glucose disposal in different tissues, as indicated by changes in PDHCa activity, may contribute to glucose-intolerance and insulin-resistance in GTG-obese mice and that the response of the PDHC to insulin during the development of obesity varies in different tissues.
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MESH Headings
- Adipose Tissue/drug effects
- Adipose Tissue/enzymology
- Adipose Tissue/ultrastructure
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/enzymology
- Adipose Tissue, Brown/ultrastructure
- Animals
- Aurothioglucose
- Blood Glucose/metabolism
- Glucose/pharmacology
- Insulin/blood
- Kinetics
- Male
- Mice
- Mice, Inbred CBA
- Mitochondria/enzymology
- Mitochondria, Heart/drug effects
- Mitochondria, Heart/enzymology
- Mitochondria, Liver/drug effects
- Mitochondria, Liver/enzymology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/ultrastructure
- Obesity/chemically induced
- Obesity/enzymology
- Pyruvate Dehydrogenase Complex/metabolism
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Affiliation(s)
- J M Bryson
- Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, N.S.W., Australia
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12
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Blair SC, Caterson ID, Cooney GJ. Effect of adrenalectomy on glucose tolerance and lipid metabolism in gold-thioglucose obese mice. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 266:E993-1000. [PMID: 8023932 DOI: 10.1152/ajpendo.1994.266.6.e993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of adrenalectomy (ADX) on body weight, lipogenesis, and glucose tolerance was investigated in mice made obese by a single intraperitoneal injection of gold-thioglucose (GTG). Five weeks after ADX the weight of GTG-obese mice was significantly decreased (GTG-obese+sham-ADX: 39.8 +/- 0.8 g; GTG-obese+ADX: 27.6 +/- 1.1 g; P < 0.05). ADX also reduced serum glucose (GTG-obese+sham-ADX: 16.5 +/- 0.6 mmol/l; GTG-obese+ADX: 10.8 +/- 0.5 mmol/l; P < 0.05) and serum insulin concentrations (GTG-obese+sham-ADX: 197 +/- 36 microU/ml; GTG-obese+ADX: 38 +/- 7 microU/ml; P < 0.05) of fed GTG-obese mice and greatly improved glucose tolerance. ADX lowered liver glycogen content and reduced the fatty acid content of liver, epididymal white adipose tissue (WAT), and interscapular brown adipose tissue (BAT) of fed GTG-obese mice. Lipid synthesis in liver and WAT of GTG-obese mice was decreased by ADX, but lipogenesis in BAT was increased, possibly to provide substrate for increased thermogenesis in this tissue. Effects of ADX on metabolism were not confined to GTG-injected mice, as ADX also reduced body weight and altered the glucose tolerance of age-matched control mice. ADX increased lipid synthesis in liver, WAT, and BAT of fed control mice without an increase in lipid deposition, indicating that there was increased lipid turnover in these lipogenic tissues of ADX mice. ADX reduced the fasting blood glucose concentration of both control and GTG-obese mice to a level below that of sham-ADX control mice (sham-ADX control: 6.0 +/- 0.4 mM; ADX control: 2.9 +/- 0.5 mM; ADX GTG-obese: 3.3 +/- 0.2 mM).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S C Blair
- Department of Endocrinology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
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13
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Chen C, Williams PF, Caterson ID. Liver and peripheral tissue glycogen metabolism in obese mice: effect of a mixed meal. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 265:E743-51. [PMID: 8238501 DOI: 10.1152/ajpendo.1993.265.5.e743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Glycogen metabolism in the liver, skeletal muscle, cardiac muscle, and white adipose tissue was studied in gold thioglucose (GTG) obese mice after fasting and during refeeding. Prolonged (48 h) fasted control and GTG mice were refed with standard laboratory diet for 24 h. During fasting and refeeding, the changes in glycogen content and the activity of glycogen synthase I and R and phosphorylase alpha in the liver were similar in lean and GTG mice. However, the glycogen storage in the livers from GTG mice was always greater than that in lean animals. In GTG mice the activity of liver glycogen synthase I and R was significantly higher than that in lean animals 3 and 6 h after refeeding. The activity of liver phosphorylase alpha in GTG mice was higher than that in lean mice after refeeding. There were no significant differences in the glycogen content of white adipose tissue, cardiac muscle, and skeletal muscle from lean and GTG mice during the entire study. The results of this study suggest that increased glycogen storage in the liver is a major alteration in nonoxidative glucose metabolism and contributes to the development of insulin resistance and glucose intolerance in GTG obese mice.
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Affiliation(s)
- C Chen
- Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
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Bryson JM, Cooney GJ, Wensley VR, Blair SC, Caterson ID. Diurnal patterns of cardiac and hepatic pyruvate dehydrogenase complex activity in gold-thioglucose-obese mice. Biochem J 1993; 295 ( Pt 3):731-4. [PMID: 8240285 PMCID: PMC1134621 DOI: 10.1042/bj2950731] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The diurnal pattern of the activity of the pyruvate dehydrogenase complex (PDHC) was studied in the heart and liver of gold-thioglucose (GTG)-obese mice and age-matched controls. The diurnal pattern of lipogenesis was also measured in the liver. Both lean and obese mice had one main eating period, from 20:00 to 24:00 h. Eating produced no change in serum glucose of control mice but there was a significant rise in serum insulin and triacylglycerols. There was also a 3-fold increase in cardiac PDHC activity and a 3-fold increase in hepatic lipogenesis in the control mice, but little change in hepatic PDHC activity. GTG-obese mice were hyperglycaemic, hyperinsulinaemic and hypertriglyceridaemic at all times studied, with significant increases in these parameters being seen in response to eating. Eating produced little change in cardiac PDHC activity, but there was a 5-fold increase in hepatic PDHC activity, paralleled by a 10-fold increase in hepatic lipogenesis. Hepatic PDHC activity was significantly higher in GTG-obese mice at all times except 16:00 h. The simultaneous rise of hepatic PDHC activity, lipogenesis and serum triacylglycerols in GTG-obese mice suggests an increased utilization of glucose for lipogenesis. The lack of change in heart PDHC activity in GTG-obese mice over 24 h suggests that a general decrease in PDHC activity may contribute to the development of the glucose intolerance and insulin resistance of obesity and non-insulin-dependent diabetes. However, it appears that a different level of metabolic control allows hepatic PDHC activity of the same obese animals to increase in response to hyperinsulinaemia and contribute to the higher rates of lipogenesis seen in obese mice.
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Affiliation(s)
- J M Bryson
- Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, N.S.W., Australia
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Mercer SW, Denton RM, Taberner PV. The development of resistance to the lipogenic effects of insulin in brown and white adipose tissue of spontaneously type II diabetic male CBA/Ca mice. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1992; 24:941-4. [PMID: 1612184 DOI: 10.1016/0020-711x(92)90101-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. Lipogenesis in brown adipose tissue and white adipose tissue (WAT) was measured in vivo in spontaneously type II diabetic male CBA/Ca mice. 2. Lipogenic rates rose sharply in brown adipose tissue between the third and fourth month of life, concomitant with the onset of hyperinsulinaemia. However, lipogenic rates fell between the fourth and fifth month of age, and remained low, despite increasing circulating insulin concentrations. 3. Lipogenesis in white adipose tissue showed a modest response to hyperinsulinaemia followed by increasing resistance to elevated insulin concentrations after 5 months of age. 4. Studies involving either the injection of insulin or the intubation of glucose provided further evidence for the development of insulin resistance in both brown and white adipose tissue.
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Affiliation(s)
- S W Mercer
- Department of Biochemistry, University of Bristol Medical School, U.K
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Kita K, Furuse M, Yang SI, Okumura J. Influence of dietary sorbose on lipogenesis in gold thioglucose-injected obese mice. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1992; 24:249-53. [PMID: 1733790 DOI: 10.1016/0020-711x(92)90254-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. The influence of dietary sorbose on food intake and fatty acid synthesis of the liver and epididymal white adipose tissue (EWAT) was investigated in gold thioglucose (GTG)-injected obese mice from 12 to 14 weeks of age. 2. Sorbose was supplemented to a semi-purified diet at a level of 200 g/kg diet at the expense of sucrose. 3. On the last day of the experiment, fatty acids synthesis in the liver and EWAT was measured using an i.p. injection [1-14C]sodium acetate. 4. The decreases in body weight and food intake by dietary sorbose in GTG-injected obese mice were greater than those in control mice. 5. Lipid content and fatty acid synthesis in the liver and EWAT of control mice were not influenced by dietary sorbose. 6. In GTG-injected obese mice, the reduction of food intake by dietary sorbose suppressed fatty acid synthesis and lipid deposition in both liver and EWAT.
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Affiliation(s)
- K Kita
- Laboratory of Animal Nutrition, School of Agriculture, Nagoya University, Japan
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Blair SC, Cooney GJ, Denyer GS, Williams PF, Caterson ID. Differences in lipogenesis in tissues of control and gold-thioglucose obese mice after an isocaloric meal. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1085:385-8. [PMID: 1911874 DOI: 10.1016/0005-2760(91)90145-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Lipogenesis was measured in 2 and 5 week gold-thioglucose (GTG) obese mice after a single meal of 0.5 g of standard chow. Compared to control mice the rate of lipogenesis in GTG obese mice, was 4-fold higher in liver and 10-fold higher in white adipose tissue (WAT). In brown adipose tissue (BAT) of GTG-injected mice the lipogenic rate was only 50% of that of controls. These results indicate that the increased lipid synthesis observed in GTG-injected mice is not due solely to hyperphagia and that some other stimuli, such as increased basal insulin levels and/or decreased thermogenesis and insulin resistance in BAT, contribute to the high rates of fat synthesis in this animal model of obesity.
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Affiliation(s)
- S C Blair
- Department of Endocrinology, Royal Prince Alfred Hospital, Camperdown, N.S.W. Australia
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18
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Trayhurn P, Wusteman MC. Lipogenesis in genetically diabetic (db/db) mice: developmental changes in brown adipose tissue, white adipose tissue and the liver. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1047:168-74. [PMID: 2248973 DOI: 10.1016/0005-2760(90)90043-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Developmental changes in lipogenesis have been examined in interscapular brown adipose tissue (BAT), epididymal white adipose tissue and the liver of genetically diabetic (db/db) mice and their normal siblings. Lipogenesis was measured in vivo with 3H2O, from weaning (21 days of age) until 20 weeks of age. Hyperinsulinaemia was evident in db/db mice at all ages. Low rates of lipogenesis were observed at weaning in tissues of both groups of mice, but the rate rose rapidly in the first few days post-weaning. In normal mice, peak lipogenesis was obtained in each tissue at 4-5 weeks of age, and there were no major changes (on a whole-tissue basis) thereafter. A different developmental pattern was apparent in db/db mice. The rate of lipogenesis in BAT rose sharply after weaning, reaching a peak at 26 days of age (several times higher than normal mice), and then falling rapidly such that by 45 days of age it was lower than in normal mice; at age 20 weeks lipogenesis in BAT of the diabetic animals was negligible. In white adipose tissue of the db/db mutants lipogenesis (per tissue) reached a maximum at 5 weeks of age, and fell substantially between 10 and 20 weeks of age. Hepatic lipogenesis in the db/db mice rose progressively from weaning until 8 weeks of age, and then decreased. Except at weaning, hepatic lipogenesis (per tissue) was much greater in db/db mice than in normal mice, and the liver was a more important site of lipogenesis in diabetic mice than in normals, accounting for up to 60% of the whole-body total. In contrast, BAT accounted for a considerably smaller proportion of whole-body lipogenesis in db/db mice than in normal mice. It is concluded that there are major developmental differences in lipogenesis between tissues of db/db mice, and between diabetic and normal animals. The data suggest that there is an early and preferential development of insulin resistance in BAT of the db/db mutant.
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Affiliation(s)
- P Trayhurn
- Dunn Nutrition Laboratory, Medical Research Council, Cambridge, U.K
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Cooney GJ, Denyer GS, Kerbey AL, Frankland RL, Blair SC, Williams PF, Caterson ID. Pyruvate dehydrogenase-complex activity in brown adipose tissue of gold thioglucose-obese mice. Biochem J 1990; 270:257-9. [PMID: 2118759 PMCID: PMC1131707 DOI: 10.1042/bj2700257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The activity of pyruvate dehydrogenase (PDH) complex and PDH kinase were measured in brown adipose tissue (BAT) of 4-week-gold thioglucose (GTG)-obese mice. The proportion of PDH complex in the active dephosphorylated form was 2-fold higher in BAT of post-absorptive obese mice compared with lean controls. This result was consistent with the higher circulating insulin concentration observed in GTG-obese mice. In both obese and lean mice the PDH-complex activity in BAT decreased after 24 h starvation and increased in response to supraphysiological insulin injection, indicating that the PDH complex is insulin-responsive in BAT of GTG-obese mice. There was no difference in the PDH kinase activity of BAT in post-absorptive or insulin-injected lean and obese mice, suggesting that the higher PDH-complex activity in obese mice was not due to decreased PDH kinase activity. There is no evidence for a decreased activity of PDH complex contributing to insulin resistance in BAT of 4-week-GTG-obese mice.
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Affiliation(s)
- G J Cooney
- Department of Endocrinology, Royal Prince Alfred Hospital, N.S.W., Australia
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