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Subramaniam M, Enns CB, Loewen ME. Sigmoidal kinetics define porcine intestinal segregation of electrogenic monosaccharide transport systems as having multiple transporter population involvement. Physiol Rep 2019; 7:e14090. [PMID: 31062524 PMCID: PMC6503033 DOI: 10.14814/phy2.14090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 01/22/2023] Open
Abstract
Kinetic characterization of electrogenic sodium-dependent transport in Ussing chambers of d-glucose and d-galactose demonstrated sigmoidal/Hill kinetics in the porcine jejunum and ileum, with the absence of transport in the distal colon. In the jejunum, a high-affinity, super-low-capacity (Ha/sLc) kinetic system accounted for glucose transport, and a low-affinity, low-capacity (La/Lc) kinetic system accounted for galactose transport. In contrast, the ileum demonstrated a high-affinity, super-high-capacity (Ha/sHc) glucose transport and a low-affinity, high-capacity (La/Hc) galactose transport systems. Jejunal glucose transport was not inhibited by dapagliflozin, but galactose transport was inhibited. Comparatively, ileal glucose and galactose transport were both sensitive to dapagliflozin. Genomic and gene expression analyses identified 10 of the 12 known SLC5A family members in the porcine jejunum, ileum, and distal colon. Dominant SGLT1 (SLC5A1) and SGLT3 (SLC5A4) expression was associated with the sigmoidal Ha/sLc glucose and La/Lc galactose transport systems in the jejunum. Comparatively, the dominant expression of SGLT1 (SLC5A1) in the ileum was only associated with Ha glucose and La galactose kinetic systems. However, the sigmoidal kinetics and overall high capacity (Hc) of transport is unlikely accounted for by SGLT1 (SLC5A1) alone. Finally, the absence of transport and lack of pharmacological inhibition in the colon was associated with the poor expression of SLC5A genes. Altogether, the results demonstrated intestinal segregation of monosaccharide transport fit different sigmoidal kinetic systems. This reveals multiple transporter populations in each system, supported by gene expression profiles and pharmacological inhibition. Overall, this work demonstrates a complexity to transporter involvement in intestinal electrogenic monosaccharide absorption systems not previously defined.
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Affiliation(s)
- Marina Subramaniam
- Department of Veterinary Biomedical SciencesWestern College of Veterinary MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Cole B. Enns
- Department of Veterinary Biomedical SciencesWestern College of Veterinary MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Matthew E. Loewen
- Department of Veterinary Biomedical SciencesWestern College of Veterinary MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
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Subramaniam M, Weber LP, Loewen ME. Intestinal electrogenic sodium-dependent glucose absorption in tilapia and trout reveal species differences in SLC5A-associated kinetic segmental segregation. Am J Physiol Regul Integr Comp Physiol 2019; 316:R222-R234. [PMID: 30601703 PMCID: PMC6459381 DOI: 10.1152/ajpregu.00304.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/12/2018] [Accepted: 12/22/2018] [Indexed: 12/16/2022]
Abstract
Electrogenic sodium-dependent glucose transport along the length of the intestine was compared between the omnivorous Nile tilapia ( Oreochromis niloticus) and the carnivorous rainbow trout ( Oncorhynchus mykiss) in Ussing chambers. In tilapia, a high-affinity, high-capacity kinetic system accounted for the transport throughout the proximal intestine, midintestine, and hindgut segments. Similar dapagliflozin and phloridzin dihydrate inhibition across all segments support this homogenous high-affinity, high-capacity system throughout the tilapia intestine. Genomic and gene expression analysis supported findings by identifying 10 of the known 12 SLC5A family members, with homogeneous expression throughout the segments with dominant expression of sodium-glucose cotransporter 1 (SGLT1; SLC5A1) and sodium-myoinositol cotransporter 2 (SMIT2; SLC5A11). In contrast, trout's electrogenic sodium-dependent glucose absorption was 20-35 times lower and segregated into three significantly different kinetic systems found in different anatomical segments: a high-affinity, low-capacity system in the pyloric ceca; a super-high-affinity, low-capacity system in the midgut; and a low-affinity, low-capacity system in the hindgut. Genomic and gene expression analysis found 5 of the known 12 SLC5A family members with dominant expression of SGLT1 ( SLC5A1), sodium-glucose cotransporter 2 (SGLT2; SLC5A2), and SMIT2 ( SLC5A11) in the pyloric ceca, and only SGLT1 ( SLC5A1) in the midgut, accounting for differences in kinetics between the two. The hindgut presented a low-affinity, low-capacity system partially attributed to a decrease in SGLT1 ( SLC5A1). Overall, the omnivorous tilapia had a higher electrogenic glucose absorption than the carnivorous trout, represented with different kinetic systems and a greater expression and number of SLC5A orthologs. Fish differ from mammals, having hindgut electrogenic glucose absorption and segment specific transport kinetics.
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Affiliation(s)
- Marina Subramaniam
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan , Saskatoon, Saskatchewan , Canada
| | - Lynn P Weber
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan , Saskatoon, Saskatchewan , Canada
| | - Matthew E Loewen
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan , Saskatoon, Saskatchewan , Canada
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Quandt JE, Barletta M, Cornell KK, Giguère S, Hofmeister EH. Evaluation of a point-of-care blood glucose monitor in healthy goats. J Vet Emerg Crit Care (San Antonio) 2018; 28:45-53. [PMID: 29314531 DOI: 10.1111/vec.12686] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 04/22/2016] [Accepted: 05/17/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To assess agreement between a point-of-care glucometer (POCG) and a laboratory chemistry analyzer for blood glucose measurements in goats. DESIGN Prospective study. SETTING University teaching hospital. ANIMALS Eighteen healthy adult goats. INVESTIGATIONS Whole blood samples were obtained via jugular venipuncture prior to premedication with xylazine and butorphanol (T0), following premedication (T20), and after 1 hour of inhalant anesthesia (T60). Each sample was tested with a POCG and a laboratory analyzer (HITA). Agreement was assessed using concordance correlation coefficients and calculation of bias and 95% limits of agreement. MEASUREMENTS AND MAIN RESULTS Mean blood glucose concentration at T0 was 3.9 ± 0.6 mmol/L (70 ± 10 mg/dL; POCG) and 2.9 ± 0.4 mmol/dL (53 ± 8 mg/dL; HITA). Glucose concentrations at T20 were 6.7 ± 2.4 mmol/L (121 ± 43 mg/dL) and 5.4 ± 2.1 mmol/L (97 ± 37 mg/dL) and at T60 were 5.7 ± 1.7 mmol/L (102 ± 31 mg/dL) and 4.7 ± 1.3 mmol/L (85 ± 24 mg/dL) when measured with the POCG and HITA, respectively. The POCG overestimated blood glucose compared to the HITA. The bias ± SD was 1.08 ± 0.53 mmol/L (19.4 ± 9.5 mg/dL) (95% LOA 0.04 to 2.11 mmol/L [0.7 to 38.0 mg/dL]) and the concordance correlation coefficient was 0.82. After correcting the results of the POCG using a mixed-effects linear model, the bias was 0.0 ± 0.38 mmol/L (0.0 ± 6.8 mg/dL) (95% LOA ± 0.74 mmol/L [± 13.4 mg/dL]) and the concordance correlation coefficient was 0.98. CONCLUSIONS The POCG overestimated blood glucose concentrations in goats, compared to the HITA, but when the POCG concentrations were corrected, the agreement was excellent.
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Affiliation(s)
- Jane E Quandt
- Department of Small Animal Medicine and Surgery (Quandt, Cornell, Hofmeister), and the Department of Large Animal Medicine (Barletta, Giguère), College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Michele Barletta
- Department of Small Animal Medicine and Surgery (Quandt, Cornell, Hofmeister), and the Department of Large Animal Medicine (Barletta, Giguère), College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Karen K Cornell
- Department of Small Animal Medicine and Surgery (Quandt, Cornell, Hofmeister), and the Department of Large Animal Medicine (Barletta, Giguère), College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Steeve Giguère
- Department of Small Animal Medicine and Surgery (Quandt, Cornell, Hofmeister), and the Department of Large Animal Medicine (Barletta, Giguère), College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Erik H Hofmeister
- Department of Small Animal Medicine and Surgery (Quandt, Cornell, Hofmeister), and the Department of Large Animal Medicine (Barletta, Giguère), College of Veterinary Medicine, University of Georgia, Athens, GA 30602
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Reinhart JM, Yancey MR, Girard-Denton JD, Schermerhorn T. Determination of tonicity effects of ketoacids and lactate by use of two canine red blood cell assays. Am J Vet Res 2015; 76:77-83. [PMID: 25535664 DOI: 10.2460/ajvr.76.1.77] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the tonicity effects of β-hydroxybutyrate, acetoacetate, and lactate in canine RBCs. SAMPLE RBCs from approximately 40 dogs. PROCEDURES 2 in vitro methods were used to conduct 4 experiments. The modified osmotic fragility assay was used to measure the ability of ketoacid salts added to serial sucrose dilutions to protect RBCs from osmotic hemolysis. In a second assay, a handheld cell counting device was used to measure changes in RBC diameter to assess the tonicity effect of solutions of ketoacid and lactate salts. RESULTS For the modified osmotic fragility assay, all ketoacid salts had an osmoprotective effect, but the effect was determined to be completely attributable to the tonicity effect of added cations (sodium and lithium) and not the ketoacid moieties. However, both the sodium and lithium lactate salts provided osmoprotection attributable to both the cation and lactate anion. For the second assay, RBC diameter was significantly increased with the addition of urea (an ineffective osmole) but did not change with the addition of glucose (an effective osmole), which established the behaviors of ineffective and effective osmoles in this assay. The RBC diameter was significantly increased over that of control samples by the addition of sodium β-hydroxybutyrate, lithium acetoacetate, and lithium lactate but was decreased by the addition of sodium lactate. CONCLUSIONS AND CLINICAL RELEVANCE For both assays, β-hydroxybutyrate and acetoacetate acted as ineffective osmoles, whereas lactate acted as an effective osmole in 3 of 4 experiments.
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Affiliation(s)
- Jennifer M Reinhart
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
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Abstract
The glucokinase (GK) enzyme (EC 2.7.1.1.) is essential for the use of dietary glucose because it is the first enzyme to phosphorylate glucose in excess in different key tissues such as the pancreas and liver. The objective of the present review is not to fully describe the biochemical characteristics and the genetics of this enzyme but to detail its nutritional regulation in different vertebrates from fish to human. Indeed, the present review will describe the existence of the GK enzyme in different animal species that have naturally different levels of carbohydrate in their diets. Thus, some studies have been performed to analyse the nutritional regulation of the GK enzyme in humans and rodents (having high levels of dietary carbohydrates in their diets), in the chicken (moderate level of carbohydrates in its diet) and rainbow trout (no carbohydrate intake in its diet). All these data illustrate the nutritional importance of the GK enzyme irrespective of feeding habits, even in animals known to poorly use dietary carbohydrates (carnivorous species).
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Expression and regulation of facilitative glucose transporters in equine insulin-sensitive tissue: from physiology to pathology. ISRN VETERINARY SCIENCE 2014; 2014:409547. [PMID: 24977043 PMCID: PMC4060548 DOI: 10.1155/2014/409547] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/09/2013] [Indexed: 01/12/2023]
Abstract
Glucose uptake is the rate-limiting step in glucose utilization in mammalians and is tightly regulated by a family of specialized proteins, called the facilitated glucose transporters (GLUTs/SLC2). GLUT4, the major isoform in insulin-responsive tissue, translocates from an intracellular pool to the cell surface and as such determines insulin-stimulated glucose uptake. However, despite intensive research over 50 years, the insulin-dependent and -independent pathways that mediate GLUT4 translocation are not fully elucidated in any species. Insulin resistance (IR) is one of the hallmarks of equine metabolic syndrome and is the most common metabolic predisposition for laminitis in horses. IR is characterized by the impaired ability of insulin to stimulate glucose disposal into insulin-sensitive tissues. Similar to other species, the functional capability of the insulin-responsive GLUTs is impaired in muscle and adipose tissue during IR in horses. However, the molecular mechanisms of altered glucose transport remain elusive in all species, and there is still much to learn about the physiological and pathophysiological functions of the GLUT family members, especially in regard to class III. Since GLUTs are key regulators of whole-body glucose homeostasis, they have received considerable attention as potential therapeutic targets to treat metabolic disorders in human and equine patients.
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Suska M, Skotnicka E. Changes in Adenylate Nucleotides Concentration and Na, K-ATPase Activities in Erythrocytes of Horses in Function of Breed and Sex. Vet Med Int 2009; 2010:987309. [PMID: 20445796 PMCID: PMC2859025 DOI: 10.4061/2010/987309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 09/18/2009] [Accepted: 10/13/2009] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to examine the relationships between the concentrations of ATP, ADP, AMP (HPLC methods), total nucleotide pool (TAN), adenylate energy charge (AEC) and Na(+), K(+)-ATPase erythrocytic activities (by Choi's method) of horses as a function of breed and sex. The studies were conducted on 54 horses (stallions and mares) of different constitution types: breathing constitution (Wielkopolska and Hanoverian breed) and digestive constitution (Ardenian breed). Horse erythrocytes, independently of examined breed, present low ATP concentration in comparison to other mammal species while retaining relatively high AEC. Erythrocytes of breathing constitution type horses appear to have a more intensive glucose metabolism and a more efficient energetic metabolism when compared to digestive constitution type horses. The conclusions may be proven by significantly higher ATP concentration, higher TAN and significantly higher AEC in breathing constitution type horses compared to the digestive constitution type. Sex does not significantly influence adenine nucleotides concentration in the erythrocytes of the examined horses, however, stallions have slightly higher values in comparison to mares. A positive correlation was found between Na(+), K(+), -ATPase activity, ATP, ADP and AMP concentration and TAN in Wielkopolska and Ardenian breeds, which was not confirmed for the Hanoverian breed.
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Affiliation(s)
- Maria Suska
- Department of Physiology, Faculty of Life Sciences, University of Szczecin, Piastów 40 B, av, bl. 6, 71-065 Szczecin, Poland
| | - Ewa Skotnicka
- Department of Physiology, Faculty of Life Sciences, University of Szczecin, Piastów 40 B, av, bl. 6, 71-065 Szczecin, Poland
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Muhlhausler BS, Duffield JA, Ozanne SE, Pilgrim C, Turner N, Morrison JL, McMillen IC. The transition from fetal growth restriction to accelerated postnatal growth: a potential role for insulin signalling in skeletal muscle. J Physiol 2009; 587:4199-211. [PMID: 19622603 DOI: 10.1113/jphysiol.2009.173161] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A world-wide series of epidemiological and experimental studies have demonstrated that there is an association between being small at birth, accelerated growth in early postnatal life and the emergence of insulin resistance in adult life. The aim of this study was to investigate why accelerated growth occurs in postnatal life after in utero growth restriction. Samples of quadriceps muscle were collected at approximately 140 days gestation (term approximately 150 days gestation) from normally grown fetal lambs (Control, n = 7) and from growth restricted fetal lambs (placentally restricted: PR, n = 8) and from Control (n = 14) and PR (n = 9) lambs at 21 days after birth. The abundance of the insulin and IGF1 receptor protein was higher in the quadriceps muscle of the PR fetus, but there was a lower abundance of the insulin signalling molecule PKC, and GLUT4 protein in the PR group. At 21 days of postnatal age, insulin receptor abundance remained higher in the muscle of the PR lamb, and there was also an up-regulation of the insulin signalling molecules, PI3Kinase p85, Akt1 and Akt2 and of the GLUT4 protein in the PR group. Fetal growth restriction therefore results in an increased abundance of the insulin receptor in skeletal muscle, which persists after birth when it is associated with an upregulation of insulin signalling molecules and the glucose transporter, GLUT4. These data provide evidence that the origins of the accelerated growth experienced by the small baby after birth lie in the adaptive response of the growth restricted fetus to its low placental substrate supply.
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Affiliation(s)
- B S Muhlhausler
- Early Origins of Adult Health Research Group, Sansom Research Institute, University of South Australia, Adelaide 5001, Australia
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LEBLANC AMYK, WALL JONS, MORANDI FEDERICA, KENNEl STEPHENJ, STUCKEY ALAN, JAKOBY BJOERN, TOWNSEND DAVIDW, DANIEL GREGORYB. NORMAL THORACIC AND ABDOMINAL DISTRIBUTION OF 2-DEOXY-2-[18F]FLUORO-d-GLUCOSE (18FDG) IN ADULT CATS. Vet Radiol Ultrasound 2009; 50:436-41. [DOI: 10.1111/j.1740-8261.2009.01562.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Tanaka A, Urabe S, Takeguchi A, Mizutani H, Sako T, Imai S, Yoshimura I, Kimura N, Arai T. Comparison of Activities of Enzymes Related to Energy Metabolism in Peripheral Leukocytes and Livers between Holstein Dairy Cows and ICR Mice. Vet Res Commun 2006; 30:29-38. [PMID: 16362608 DOI: 10.1007/s11259-005-3223-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2004] [Indexed: 11/25/2022]
Abstract
Activities of enzymes related to energy metabolism and isoenzyme patterns of lactate dehydrogenase (LDH) were determined in peripheral leukocytes and livers of Holstein dairy cows and Institute of Cancer Research (ICR) mice. In dairy cow liver, activities of enzymes in glycolysis, malate-aspartate shuttle and lipogenesis were lower, but activities of glucose-6-phosphatase in gluconeogenesis were higher than those in mouse liver. Glucokinase activities were below detection limit in leukocytes and liver of the cows. Dairy cow leukocytes and liver showed the isoenzyme patterns with dominance of LDH-1, -2 and-3, whereas mouse leukocytes and liver showed that LDH-5 was dominant. The LDH isoenzyme patterns were very similar between leukocytes and liver in each animal species. Some enzymes in leukocytes may reflect those enzymes activities in liver and be a useful indicator for energy metabolism in animals.
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Affiliation(s)
- A Tanaka
- Department of Veterinary Science, Nippon Veterinary and Animal Science University, Musashino, Tokyo 180-8602, Japan
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Takeguchi A, Urabe S, Tanaka A, Sako T, Washizu T, Morinaga N, Kimura N, Arai T. Activities of enzymes in some types of peripheral leucocytes may reflect the differences in nutrient metabolism between dogs and cats. Res Vet Sci 2005; 78:21-4. [PMID: 15500835 DOI: 10.1016/j.rvsc.2004.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2004] [Indexed: 11/28/2022]
Abstract
Plasma metabolites and immunoreactive insulin (IRI) concentrations and enzyme activities of some types of peripheral leucocytes were measured to clarify one aspect of the differences in nutrient metabolism between dogs and cats. There were no significant differences in plasma concentrations of glucose, triglyceride, free fatty acids and IRI between dogs and cats. Higher total cholesterol and lower HDL cholesterol concentrations were observed in feline plasma, and H/T ratio (HDL/total cholesterol concentrations) was significantly lower than that in canine plasma. The cytosolic activities of fructokinase (FK), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) were significantly higher and the activities of cytosolic malate dehydrogenase (MDH) and mitochondrial glutamate dehydrogenase (GLDH) were significantly lower in feline leucocytes than those in canine leucocytes. Higher activities of FK, PK and G6PD, which regulate the rate of biosynthesis of fatty acids, may reflect the different characteristics in nutrient metabolism in feline tissues from canine tissues.
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Affiliation(s)
- A Takeguchi
- Department of Veterinary Science, Nippon Veterinary and Animal Science University, Kyonancho, Musashino, Tokyo 180-8602, Japan
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Magori E, Nakamura M, Inoue A, Tanaka A, Sasaki N, Fukuda H, Mizutani H, Sako T, Kimura N, Arai T. Malate dehydrogenase activities are lower in some types of peripheral leucocytes of dogs and cats with type 1 diabetes mellitus. Res Vet Sci 2005; 78:39-44. [PMID: 15500838 DOI: 10.1016/j.rvsc.2004.06.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2004] [Indexed: 11/24/2022]
Abstract
The activities of the enzymes in the malate-aspartate shuttle were measured in peripheral leucocytes of spontaneous type 1 diabetic dogs and cats treated with insulin injections. In the diabetic dogs and cats, fasting plasma glucose concentrations were three- or fourfold greater than the control levels in spite of insulin injections and the activities of cytosolic malate dehydrogenase (MDH), one of pivotal enzymes in the malate-aspartate shuttle, were remarkably lower than the controls. Depressed expression of cytosolic MDH mRNA was confirmed by RT-PCR analysis in the diabetic animals. The cytosolic ratio of MDH/lactate dehydrogenase (LDH) activity (M / L ratio) in leucocytes of the diabetic animals was significantly lower than that of normal control animals. The smaller M / L ratio appeared to reflect depression of energy metabolism in the diabetic animals. Intrinsically lower and further decreased MDH activities may be factors that induce insulin resistance observed in diabetic cats.
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Affiliation(s)
- E Magori
- Division of Veterinary Biochemistry, Department of Veterinary Science, Nippon Veterinary and Animal Science University, 1-7-1 Kyonancho, Musashino, Tokyo 180-8602, Japan
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Milano GD, Hotston-Moore A, Lobley GE. Influence of hepatic ammonia removal on ureagenesis, amino acid utilization and energy metabolism in the ovine liver. Br J Nutr 2000; 83:307-15. [PMID: 10884719 DOI: 10.1017/s0007114500000386] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mass transfers of O2, glucose, NH3, urea and amino acids across the portal-drained viscera (PDV) and the liver were quantified, by arterio-venous techniques, during the last 4 h of a 100 h infusion of 0 (basal), 150 or 400 mumol NH4HCO3/min into the mesenteric vein of three sheep given 800 g grass pellets/d and arranged in a 3 x 3 Latin-square design. Urea irreversible loss rate (ILR) was also determined by continuous infusion of [14C]urea over the last 52 h of each experimental period. PDV and liver movements of glucose, O2 and amino acids were unaltered by NH4HCO3 administration, although there was an increase in PDV absorption of non-essential amino acids (P = 0.037) and a trend for higher liver O2 consumption and portal appearance of total amino acid-N, glucogenic and non-essential amino acids at the highest level of infusion. PDV extraction of urea-N (P = 0.015) and liver removal of NH3 (P < 0.001), release of urea-N (P = 0.002) and urea ILR (P = 0.001) were all increased by NH4HCO3 infusion. Hepatic urea-N release (y) and NH3 extraction (x) were linearly related (R2 0.89), with the slope of the regression not different from unity, both for estimations based on liver mass transfers (1.16; SE 0.144; P(b) not equal to 1 = 0.31) and [14C]urea (0.97; SE 0.123; P(b) not equal to 1 = 0.84). The study indicates that a sustained 1.5 or 2.4-fold increase in the basal NH3 supply to the liver did not impair glucose or amino acid supply to non-splanchnic tissues; nor were additional N inputs to the ornithine cycle necessary to convert excess NH3 to urea. Half of the extra NH3 removed by the liver was, apparently, utilized by periportal glutamate dehydrogenase and aspartate aminotransferase for sequential glutamate and aspartate synthesis and converted to urea as the 2-amino moiety of aspartate.
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Affiliation(s)
- G D Milano
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro (UNCPBA), Tandil, Argentina.
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Washizu T, Tanaka A, Sako T, Washizu M, Arai T. Comparison of the activities of enzymes related to glycolysis and gluconeogenesis in the liver of dogs and cats. Res Vet Sci 1999; 67:205-6. [PMID: 10502495 DOI: 10.1053/rvsc.1998.0305] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Activities of enzymes related to glucose metabolism were measured in canine and feline liver. There were no significant differences in plasma glucose and immunoreactive insulin concentrations between dogs and cats. Glucokinase activities were absent in feline liver, however, activities of other glycolytic enzymes such as hexokinase, phosphofructokinase and pyruvate kinase, were significantly higher than those in canine livers. Activities of rate limiting enzymes of gluconeogenesis such as pyruvate carboxylase, fructose-1, 6-bisphosphatase and glucose-6-phosphatase in feline livers were significantly higher than those in canine livers.
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Affiliation(s)
- T Washizu
- Department of Veterinary Science, Nippon Veterinary and Animal Science University, Musashino, Tokyo, 180-0023, Japan
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Arai T, Hashimoto K, Muzutani H, Kawabata T, Sako T, Washizu T. A comparison of the plasma fructose concentrations in dogs and cats and changes in the fructose concentrations in dogs following intravenous administration of fructose. Vet Res Commun 1999; 23:203-9. [PMID: 10461796 DOI: 10.1023/a:1006203807735] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The plasma concentrations of fructose, glucose, free fatty acids (FFA) and triglycerides (TG) were measured in dogs and cats. Changes in these concentrations were investigated in dogs by an intravenous fructose tolerance test (IVFTT) at a dose of 0.1 g/kg body weight. Fructose concentrations in the plasma of dogs were significantly higher than those of cats. There was no significant difference in plasma glucose concentrations between dogs and cats. Plasma FFA concentrations decreased and TG concentrations increased after feeding in both dogs and cats. During the IVFTT, the plasma fructose concentrations in the dogs increased rapidly to a peak by 2 min and then decreased to half of the peak by 5 min after the administration of fructose. Administration of fructose resulted in an increase in the plasma TG concentrations and reduced plasma FFA concentrations in the dogs. Only 4%, of the administered fructose was detected in the urine of dogs following IVFTT. Plasma fructose was considered to be rapidly absorbed and metabolized in both dogs and cats. However, as with glucose metabolism, there appear to be some differences in fructose metabolism between dogs and cats.
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Affiliation(s)
- T Arai
- Division of Veterinary Biochemistry, Nippon Veterinary and Animal Science University, Musashino, Tokyo, Japan
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Arai T, Kawaue T, Abe M, Kuramoto E, Kawakami E, Sako T, Washizu T. Comparison of glucokinase activities in the peripheral leukocytes between dogs and cats. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1998; 120:53-6. [PMID: 9827016 DOI: 10.1016/s0742-8413(98)00005-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Activities of hexokinase (HK), glucokinase (GK) and pyruvate kinase (PK), were measured. The expression of GK mRNA was investigated using reverse transcription-polymerase chain reaction (RT-PCR) in leukocytes (WBC) of dogs and cats. No significant differences between dogs and cats were found in concentrations of blood glucose and plasma insulin. Dog WBC showed GK activities and the specific fragment with predicted size of 574 bp containing conserved region including glucose- and ATP-binding domains of GK as determined with RT-PCR. However, in cat WBC, the activities and specific fragment of GK were absent. After fasting, the activities and gene expression of GK decreased greatly in the dog WBC. The cat WBC had significantly higher activities of HK and PK than dog WBC.
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Affiliation(s)
- T Arai
- Division of Veterinary Biochemistry, Nippon Veterinary and Animal Science University, Tokyo, Japan
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Washizu T, Kuramoto E, Abe M, Sako T, Arai T. A comparison of the activities of certain enzymes related to energy metabolism in leukocytes in dogs and cats. Vet Res Commun 1998; 22:187-92. [PMID: 9618890 DOI: 10.1023/a:1006073305479] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The activities of Na+,K(+)-ATPase in plasma membrane, of cytosolic enzymes and of glutamate dehydrogenase (GlGD) in mitochondria were measured in leukocytes (WBC) from dogs and cats to clarify the differences in energy metabolism in these cells. Feline WBC had significantly higher activities of hexokinase (HK), pyruvate kinase (PK) and LDH with pyruvate as substrate than did canine WBC. Canine WBC had significantly higher activities of glucokinase (GK) and GlDH than did feline WBC. Feline WBC had unique characteristics of energy metabolism in that the activities of the cytosolic enzymes under anaerobic conditions were significantly higher than those in canine WBC. It therefore appears that there are distinct differences in glucose-metabolism in WBC between dogs and cats. WBC enzyme activities are considered to reflect the metabolic state in the whole body of the animal. It is therefore suggested that changes in the activities of certain glycolytic enzymes in WBC may be useful as a diagnostic indicator in some types of metabolic disease in dogs and cats.
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Affiliation(s)
- T Washizu
- Division of Clinical Pathology, Nippon Veterinary and Animal Science University, Tokyo, Japan
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Arai T, Ogino T, Gunji M, Washizu T, Komori S, Washizu M. Changes in glucose transport activities in mammary adenocarcinoma of dogs. Res Vet Sci 1997; 62:85-6. [PMID: 9160433 DOI: 10.1016/s0034-5288(97)90188-0] [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: 02/04/2023]
Abstract
The activities of D-glucose transport (D-GT) and cytosolic enzymes were significantly higher in mammary adenocarcinoma of dogs than in mammary gland from normal dogs. The activities of D-GT in adenocarcinoma were over three-and-a-half times higher than in the controls. The K(m) value of the D-GT activity for glucose in both the adenocarcinoma and normal mammary gland was approximately 0.9 mM. The activities of the key glycolytic enzymes, hexokinase and pyruvate kinase, in the adenocarcinoma were also more than three-and-a-half times higher than in the controls. The increased activities of D-GT are considered to be accompanied by an acceleration of glucose utilisation in the adenocarcinoma of dogs.
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Affiliation(s)
- T Arai
- Department of Veterinary Science, Nippon Veterinary and Animal Science University, Tokyo, Japan
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ARAI T, KAWAUE T, ABE M, KURAMOTO E, NURUKI R, SAKO T. Glycolytic Enzyme Activities in Leukocytes of Thoroughbreds Undergoing Training Exercise. J Equine Sci 1997. [DOI: 10.1294/jes.8.113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Toshiro ARAI
- Divisions of Veterinary Biochemistry Nippon Veterinary and Animal Science University, 7-1 Kyonancho 1 chome, Musashino, Tokyo 180-8602, Japan
| | - Takumi KAWAUE
- Divisions of Veterinary Biochemistry Nippon Veterinary and Animal Science University, 7-1 Kyonancho 1 chome, Musashino, Tokyo 180-8602, Japan
| | - Maki ABE
- Divisions of Veterinary Biochemistry Nippon Veterinary and Animal Science University, 7-1 Kyonancho 1 chome, Musashino, Tokyo 180-8602, Japan
| | - Etsuko KURAMOTO
- Divisions of Veterinary Biochemistry Nippon Veterinary and Animal Science University, 7-1 Kyonancho 1 chome, Musashino, Tokyo 180-8602, Japan
| | - Ryuma NURUKI
- YCL Horse Clinic, 9-6 Kaminoda 6 chome, Urawa, Saitama 337-0977, Japan
| | - Toshinori SAKO
- Divisions of Veterinary Internal Medicine, Nippon Veterinary and Animal Science University, 7-1 Kyonancho 1 chome, Musashino, Tokyo 180-8602, Japan
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Hocquette JF, Graulet B, Castiglia-Delavaud C, Bornes F, Lepetit N, Ferre P. Insulin-sensitive glucose transporter transcript levels in calf muscles assessed with a bovine GLUT4 cDNA fragment. Int J Biochem Cell Biol 1996; 28:795-806. [PMID: 8925410 DOI: 10.1016/1357-2725(96)00013-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Previous studies have shown that the expression of the insulin-sensitive glucose transporter (GLUT4) is lower in oxidative muscles than in glycolytic muscles in bovines and goats in contrast to observations in rats. Additional experiments in this work provide very strong arguments that the immunoreactive band detected does represent GLUT4 protein, which further validates our previous results. Therefore, to determine the level of regulation, the main objective of the present study was to measure GLUT4 mRNA amounts in various bovine muscles. A 241-bp fragment of the bovine GLUT4 cDNA was cloned by polymerase chain reaction (PCR). It shares 80-90% sequence identity with related sequences in other species. This PCR-amplified bovine GLUT4 probe was used to determine the distribution of GLUT4 mRNA in bovine tissues in comparison with that of GLUT1 mRNA. Moreover, GLUT4 mRNA amounts were quantified by Northern-blot analysis in heart and seven skeletal muscles with various oxidative and glycolytic activities from seven ruminant calves. GLUT4 mRNA was detected by Northern-blot analysis only in calf insulin-sensitive tissues. In contrast, GLUT1 mRNA was detected in all tissues studied except liver. GLUT4 mRNA amount was the highest in masseter and heart, which are oxidative muscles (1.67 +/- 0.16 and 1.53 +/- 0.19 units/g wet tissue weight, respectively) and the lowest in glycolytic or oxido-glycolytic muscles (0.31 +/- 0.04 to 1.00 +/- 0.09 units/g wet tissue weight; SEM, n = 7). These data and our previous results provide evidence for translational and/or post-translational control mechanisms of bovine GLUT4 protein expression in a muscle type-specific manner.
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Affiliation(s)
- J F Hocquette
- INRA, Laboratoire Croissance et Métabolismes des Herbivores, Theix, France
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Affiliation(s)
- J F Hocquette
- Laboratoire Croissance et Métabolismes des Herbivores, INRA, Saint-Genès Champanelle, France
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