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Stefaniuk-Szmukier M, Piórkowska K, Ropka-Molik K. Equine Metabolic Syndrome: A Complex Disease Influenced by Multifactorial Genetic Factors. Genes (Basel) 2023; 14:1544. [PMID: 37628596 PMCID: PMC10454496 DOI: 10.3390/genes14081544] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/10/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
Equine metabolic syndrome (EMS) has become an important issue in modern veterinary medicine and is linked to the common, extremely painful, most-of-the-time performance-terminating hoof laminitis. The growing knowledge in the field of genetic background, inducing environmental factors, diagnosis, treatment and maintenance of affected equines led us to summarise the available information to be used not only for scientific purposes but for fieldwork. In horses, the clinical presentation of EMS includes: obesity or local fat deposition, bilateral lameness or hoof rings attributed to ongoing or previous (pasted) laminitis with the key feature of the occurrence of insulin dysregulation, disturbing the homeostasis within insulin, glucose and lipid metabolism. The management of EMS is based on dietary and fitness discipline; however, intensive research is ongoing in the field of regenerative medicine to develop modern and promising therapies.
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Affiliation(s)
- Monika Stefaniuk-Szmukier
- Department of Animal Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083 Balice, Poland
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Elliott J, Bailey SR. Consequences of adiponectin deficiency: Can they be related to the pathophysiology of laminitis? Equine Vet J 2023; 55:346-349. [PMID: 36878858 DOI: 10.1111/evj.13932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 02/22/2023] [Indexed: 03/08/2023]
Affiliation(s)
- Jonathan Elliott
- Department of Comparative Biomedical Sciences, The Royal Veterinary College University of London, London, UK
| | - Simon R Bailey
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
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Li YP, Ding JF, Abid HM, Zhang XH, Li SC, Song QZ, Jiang LH, Zhang JT, Wang HB. Oral oligofructose challenge reduces expression of glucose transport-1 and 5'-adenosine monophosphate-activated protein kinase in lamellar wall of Holstein heifer claw. Res Vet Sci 2021; 141:42-47. [PMID: 34662833 DOI: 10.1016/j.rvsc.2021.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 09/15/2021] [Accepted: 10/05/2021] [Indexed: 11/28/2022]
Abstract
The laminar tissue of bovine laminitis may undergo energy failure. The expression of glucose transport protein-1 (GLUT-1) and 5'-adenosine monophosphate-activated protein kinase (AMPK) affects the energy metabolism of digital laminar tissue. This study aimed to determine the expression of glucose uptake and AMPK in laminar wall corium of Holstein heifer claw by oral administration of oligofructose. A total of twelve clinically healthy Holstein heifers were selected and divided into two groups, including control (CON, n = 6) and experimental (OF, n = 6) groups. The heifers of OF group were given 17 g/kg BW oligofructose dissolved in water (20 mL/kg BW) and the heifers of CON group were given water only (20 mL/kg BW). The laminar tissues were collected after euthanasia. The amount of protein and transcript expression of AMPK and GLUT-1 were determined by western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR), respectively. Expressions of phosphoenolpyruvate carboxy-kinase (PEPCK), receptor-c coactivator1-α (PGC-1α) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were determined by qRT-PCR. The heifers of OF group showed no significant change in the expression and concentration of AMPK. The phosphor-(Thr172) AMPK and GLUT-1 were significantly decreased, while the gene contents of PPAR-γ and PGC-1α were significantly increased. The activation of AMPK and GLUT-1 in digital laminar tissues of heifers was inhibited, which may contribute to digital laminar tissue damage.
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Affiliation(s)
- Y P Li
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - J F Ding
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - H M Abid
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - X H Zhang
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - S C Li
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - Q Z Song
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - L H Jiang
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - J T Zhang
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China
| | - H B Wang
- Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, PR China.
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Stokes SM, Bertin FR, Stefanovski D, Belknap JK, Medina-Torres CE, Pollitt CC, van Eps AW. Lamellar energy metabolism and perfusion in the euglycaemic hyperinsulinaemic clamp model of equine laminitis. Equine Vet J 2020; 52:577-584. [PMID: 31845378 DOI: 10.1111/evj.13224] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/29/2019] [Accepted: 12/04/2019] [Indexed: 01/19/2023]
Abstract
BACKGROUND Hyperinsulinaemia is associated with the development of endocrinopathic laminitis; however, the mechanisms remain unclear. OBJECTIVES Evaluate the effects of hyperinsulinaemia on lamellar energy metabolism and perfusion during laminitis development. STUDY DESIGN In vivo experiment. METHODS Eight Standardbred horses were instrumented with a microdialysis probe in the lamellae of a forelimb. A 24 hours baseline period (BASELINE) was followed by 48 hours of a continuous euglycaemic hyperinsulinaemic clamp (EHC) from 24 to 72 hours (CLAMP). Microdialysate was collected every 6 hours and analysed for glucose, lactate and pyruvate concentrations and lactate-to-pyruvate ratio (L:P). Microdialysis urea clearance was used to estimate lamellar tissue perfusion. Archived microdialysis samples from six identically instrumented Standardbred horses served as controls (CON). Variables were compared over time and between EHC and CON horses using a mixed-effects linear regression model. RESULTS Glucose concentration decreased during the CLAMP period in CON and EHC horses (P < .001), but there was no difference between CON and EHC (P > .9). Lactate concentration increased during the CLAMP period in CON and EHC horses (P < .001), however, the rate of increase was significantly higher in EHC horses relative to CON (P = .014). There was a relative increase in pyruvate concentration in EHC horses compared with CON during the CLAMP period (P = .03). L:P increased significantly in CON horses during the CLAMP period (P < .001) but not in EHC (P = .1). Urea clearance did not change in CON (P = .9) or EHC (P = .05) during the CLAMP, but did increase in EHC relative to CON (P = .02). MAIN LIMITATIONS The effects of microdialysis probe implantation on perfusion and metabolism remain unclear. The EHC model may not mimic natural endocrinopathic laminitis. CONCLUSIONS Laminitis developed without evidence of lamellar hypoperfusion or energy stress. Therapies to improve perfusion are unlikely to affect the initial development of endocrinopathic laminitis.
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Affiliation(s)
- Simon M Stokes
- Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Gatton, Qld, Australia
| | - Francois R Bertin
- Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Gatton, Qld, Australia
| | - Darko Stefanovski
- New Bolton Center, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania
| | - James K Belknap
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Carlos E Medina-Torres
- Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Gatton, Qld, Australia
| | - Christopher C Pollitt
- Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Gatton, Qld, Australia
| | - Andrew W van Eps
- Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Gatton, Qld, Australia.,New Bolton Center, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania
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Nostell K, Lindåse S, Edberg H, Bröjer J. The effect of insulin infusion on heart rate and systemic blood pressure in horses with equine metabolic syndrome. Equine Vet J 2019; 51:733-737. [PMID: 30887546 DOI: 10.1111/evj.13110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 03/08/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND There is little evidence that horses with equine metabolic syndrome (EMS) have higher resting blood pressures than horses with normal insulin sensitivity. However, there are indications that EMS horses have an altered dynamic response to the cardiovascular effects of insulin. OBJECTIVES To examine heart rate and the systemic blood pressure response in EMS and control horses during insulin infusion. STUDY DESIGN Cross-sectional study. METHODS Horses were examined with an oral sugar test (OST) and a euglycaemic hyperinsulinaemic clamp (EHC). Based on the results from the OST, the horses were classified as either EMS or control. Blood pressure was measured before the start of the EHC and at 60, 120 and 180 min of the EHC. RESULTS There were 16 EMS and 12 control horses. Mean resting heart rate was higher for EMS horses compared with control (35.6 ± 5.1 vs. 30.3 ± 3.5 beats/min). Systolic, diastolic and mean arterial blood pressure did not differ between groups at the start of the EHC. Blood pressure decreased gradually during the EHC in the control group, whereas the EMS group showed no decline in systolic, diastolic or mean arterial pressure. MAIN LIMITATIONS Limited number of horses. CONCLUSIONS Horses with EMS have cardiovascular changes that affect resting heart rate and systemic blood pressure during insulin infusion.
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Affiliation(s)
- K Nostell
- Department of Clinical Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - S Lindåse
- Department of Clinical Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - H Edberg
- Department of Clinical Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - J Bröjer
- Department of Clinical Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K. ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med 2019; 33:335-349. [PMID: 30724412 PMCID: PMC6430910 DOI: 10.1111/jvim.15423] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/11/2019] [Indexed: 12/26/2022] Open
Abstract
Equine metabolic syndrome (EMS) is a widely recognized collection of risk factors for endocrinopathic laminitis. The most important of these risk factors is insulin dysregulation (ID). Clinicians and horse owners must recognize the presence of these risk factors so that they can be targeted and controlled to reduce the risk of laminitis attacks. Diagnosis of EMS is based partly on the horse's history and clinical examination findings, and partly on laboratory testing. Several choices of test exist which examine different facets of ID and other related metabolic disturbances. EMS is controlled mainly by dietary strategies and exercise programs that aim to improve insulin regulation and decrease obesity where present. In some cases, pharmacologic aids might be useful. Management of an EMS case is a long‐term strategy requiring diligence and discipline by the horse's carer and support and guidance from their veterinarians.
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Affiliation(s)
| | - Nicholas Frank
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts
| | - Cathy M McGowan
- Institute of Veterinary Science, University of Liverpool, Neston, United Kingdom
| | - Nicola J Menzies-Gow
- Department of clinical sciences and services, Royal Veterinary College, Herts, United Kingdom
| | - Ellen Roelfsema
- Department of Equine Sciences, Utrecht University, Utrecht, The Netherlands
| | - Ingrid Vervuert
- Faculty of Veterinary Medicine, University of Leipzig, Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Leipzig, Germany
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Germany
| | - Kerstin Fey
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany
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Sandow C, Fugler LA, Leise B, Riggs L, Monroe WT, Totaro N, Belknap J, Eades S. Ex vivo effects of insulin on the structural integrity of equine digital lamellae. Equine Vet J 2018; 51:131-135. [PMID: 29758109 DOI: 10.1111/evj.12964] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 05/05/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Laminitis has a considerable impact on the equine industry. Endocrinopathic laminitis is the most common form and affected horses often have hyperinsulinaemia due to an underlying metabolic disorder. OBJECTIVES The aim of this study was to determine if insulin weakens the structural integrity of digital lamellae and to develop an ex vivo model for the study of hyperinsulinaemia-induced lamellar failure. STUDY DESIGN Ex vivo experiment. METHODS Biomechanical testing was used to assess the structural integrity of lamellar explants exposed to either medium alone (control) or medium supplemented with insulin. Lamellar explants comprised of hoof wall, lamellar tissue and distal phalanx were harvested from four adult horses with no evidence of inflammatory disease or pre-existing disease of the digit. Following an equilibration period, explants were incubated in medium or medium supplemented with insulin (2.5 μg/ml) for 8 h prior to biomechanical testing to obtain load (N), stress (MPa), elongation to failure (mm), and Young's modulus (MPa) for each explant. Significant differences were assessed using a mixed linear model with horses as a random factor and control or insulin-treated group as a fixed factor. RESULTS Lamellar explants incubated in medium supplemented with insulin failed at significantly lower load (P = 0.0001) and lower stress (P = 0.001) and had greater elongation to failure (P = 0.02). MAIN LIMITATIONS In addition to the ex vivo nature of the study, location-dependent variability in explant structural integrity and variable diffusion of nutrients due to explant size may have been limitations. However, the study design attempted to account for these limitations through random assignment of explants to treatment groups independent of location and by evaluating stress to failure. CONCLUSIONS Insulin weakens the structural integrity of equine lamellar explants and an ex vivo model for evaluation of hyperinsulinaemia-induced lamellar failure was established. The summary is available in Spanish - see Supporting Information.
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Affiliation(s)
- C Sandow
- Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - L A Fugler
- Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - B Leise
- Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - L Riggs
- Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - W T Monroe
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana, USA
| | - N Totaro
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana, USA
| | - J Belknap
- Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - S Eades
- Department of Large Animal Clinical Sciences, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
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Nostell KEA, Lindåse SS, Bröjer JT. Blood pressure in Warmblood horses before and during a euglycemic-hyperinsulinemic clamp. Acta Vet Scand 2016; 58:65. [PMID: 27766986 PMCID: PMC5073943 DOI: 10.1186/s13028-016-0247-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background Insulin resistance (IR) in humans is related to hypertension and impaired vasodilation. Insulin administration has been shown to lower blood pressure both in insulin resistant as well as in insulin sensitive individuals. The aim of the study was to investigate the association between insulin sensitivity and alterations in blood pressure in healthy horses before and after a euglycemic-hyperinsulinemic clamp (EHC). A 3-h EHC was performed in 13 healthy horses (11 mares, 2 geldings). Blood samples for measurement of plasma glucose and insulin were collected before the start of the EHC, every 10 min during the EHC and immediately after the EHC. Mean, systolic- and diastolic blood pressure was measured before and during the final 10 min of the EHC using an indirect high-definition oscillometric monitor (HDO, horse model) applied to the middle of the coccygeal artery. Five consecutive measurements were made in each horse and on each occasion. Insulin and glucose data from the EHC were used to calculate the mean rate of glucose disposal per unit of insulin during steady state (M/I ratio). Insulin resistance was defined as a M/I ratio <5 mg/kg/min/mUL (Lindåse et al. in Am J Vet Res 77:300–309, 2016). Results Insulin administration decreased systolic, diastolic and mean arterial pressure in all horses. The M/I ratio for all horses was negatively correlated with the decrease in systolic blood pressure (r2 = 0.55, P = 0.004) and mean arterial pressure (r2 = 0.31, P = 0.048) but not diastolic blood pressure (r2 = 0.12, P = 0.26). Eight horses were defined as insulin resistant (IR) and five horses had normal insulin sensitivity. The five horses with normal insulin sensitivity showed a greater decrease in systolic blood pressure (−17.0 ± 7.4 vs. −3.4 ± 4.6 mmHg, P = 0.001) and MAP (19.2 ± 14.7 vs. 6.9 ± 8.7 mmHg, P = 0.04) than IR horses. There was no difference in the decrease in diastolic blood pressure between groups (16 ± 12.8 vs. 8.9 ± 12.1 mmHg, P = 0.17). Conclusions This study indicates that there is a relationship between insulin sensitivity and systolic and MAP in horses. However, studies on a larger number of horses are needed to confirm this association.
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Morgan RA, Keen JA, Walker BR, Hadoke PWF. Vascular Dysfunction in Horses with Endocrinopathic Laminitis. PLoS One 2016; 11:e0163815. [PMID: 27684374 PMCID: PMC5042533 DOI: 10.1371/journal.pone.0163815] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 09/14/2016] [Indexed: 11/19/2022] Open
Abstract
Endocrinopathic laminitis (EL) is a vascular condition of the equine hoof resulting in severe lameness with both welfare and economic implications. EL occurs in association with equine metabolic syndrome and equine Cushing’s disease. Vascular dysfunction, most commonly due to endothelial dysfunction, is associated with cardiovascular risk in people with metabolic syndrome and Cushing’s syndrome. We tested the hypothesis that horses with EL have vascular, specifically endothelial, dysfunction. Healthy horses (n = 6) and horses with EL (n = 6) destined for euthanasia were recruited. We studied vessels from the hooves (laminar artery, laminar vein) and the facial skin (facial skin arteries) by small vessel wire myography. The response to vasoconstrictors phenylephrine (10−9–10-5M) and 5-hydroxytryptamine (5HT; 10−9–10-5M) and the vasodilator acetylcholine (10−9–10-5M) was determined. In comparison with healthy controls, acetylcholine-induced relaxation was dramatically reduced in all intact vessels from horses with EL (% relaxation of healthy laminar arteries 323.5 ± 94.1% v EL 90.8 ± 4.4%, P = 0.01, laminar veins 129.4 ± 14.8% v EL 71.2 ± 4.1%, P = 0.005 and facial skin arteries 182.0 ± 40.7% v EL 91.4 ± 4.5%, P = 0.01). In addition, contractile responses to phenylephrine and 5HT were increased in intact laminar veins from horses with EL compared with healthy horses; these differences were endothelium-independent. Sensitivity to phenylephrine was reduced in intact laminar arteries (P = 0.006) and veins (P = 0.009) from horses with EL. Horses with EL exhibit significant vascular dysfunction in laminar vessels and in facial skin arteries. The systemic nature of the abnormalities suggest this dysfunction is associated with the underlying endocrinopathy and not local changes to the hoof.
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Affiliation(s)
- Ruth A. Morgan
- University/BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
- * E-mail:
| | - John A. Keen
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
| | - Brian R. Walker
- University/BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Patrick W. F. Hadoke
- University/BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
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Marr CM, Mair TS. EVE and EVJ online collection of equine endocrinology: recent and future directions; a great start, but still a long way to go. Equine Vet J 2016; 46:97-8. [PMID: 24329585 DOI: 10.1111/evj.12217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Abstract
Laminitis is one of the most common and frustrating clinical presentations in equine practice. While the principles of treatment for laminitis have not changed for several decades, there have been some important paradigm shifts in our understanding of laminitis. Most importantly, it is essential to consider laminitis as a clinical sign of disease and not as a disease in its own right. Once this shift in thinking has occurred, it is logical to then question what disease caused the laminitis. More than 90 per cent of horses presented with laminitis as their primary clinical sign will have developed it as a consequence of endocrine disease; most commonly equine metabolic syndrome (EMS). Given the fact that many horses will have painful protracted and/or chronic recurrent disease, a good understanding of the predisposing factors and how to diagnose and manage them is crucial. Current evidence suggests that early diagnosis and effective management of EMS should be a key aim for practising veterinary surgeons to prevent the devastating consequences of laminitis. This review will focus on EMS, its diagnosis and management.
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Affiliation(s)
- R Morgan
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - J Keen
- European Specialist in Equine Internal Medicine, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - C McGowan
- European Specialist in Equine Internal Medicine, Institute of Aging and Chronic Disease, University of Liverpool, Leahurst Campus, Neston, Cheshire CH64 7TE, UK
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Kaczmarek K, Janicki B, Głowska M. Insulin resistance in the horse: a review. JOURNAL OF APPLIED ANIMAL RESEARCH 2015. [DOI: 10.1080/09712119.2015.1091340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Venugopal C, Holmes E, Beadle R, Kearney M, Eades S. Comparison of Insulin-Induced Digital Vessel Ring Responses of Laminitic and Clinically Healthy Horses. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2014.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Wooldridge AA, Waguespack RW, Schwartz DD, Venugopal CS, Eades SC, Beadle RE. Vasorelaxation responses to insulin in laminar vessel rings from healthy, lean horses. Vet J 2014; 202:83-8. [PMID: 25155219 DOI: 10.1016/j.tvjl.2014.07.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 07/21/2014] [Accepted: 07/25/2014] [Indexed: 10/25/2022]
Abstract
Hyperinsulinemia causes laminitis experimentally and is a risk factor for naturally occurring laminitis. The aim of this study was to investigate the effects of insulin on laminar vascular relaxation and to induce insulin-associated vascular dysfunction in vitro. Relaxation responses of isolated laminar arterial and venous rings to acetylcholine and insulin were evaluated. To alter vascular function in response to insulin, all vessel rings were incubated with insulin or vehicle, submaximally contracted, administered insulin again and relaxation responses recorded. Laminar arteries were also incubated with the mitogen-activated protein kinase (MAPK) inhibitor, PD-98059. Relaxation in response to acetylcholine was not different between arteries and veins, but veins relaxed less in response to insulin than arteries. In arteries incubated with insulin, the subsequent relaxation response to insulin was blunted. Veins had minimal relaxation to insulin regardless of incubation. Arteries incubated with PD-98059 relaxed more in response to insulin than arteries not exposed to PD-98059, indicating that MAPK plays a role in maintenance of basal tone in laminar arteries. A differing response of laminar veins and arteries to insulin-induced relaxation may be important in understanding the link between hyperinsulinemia and laminitis. In vitro induction of vascular dysfunction in response to insulin in laminar arteries may be useful for testing therapeutic interventions and for understanding the pathophysiology of laminitis.
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Affiliation(s)
- A A Wooldridge
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, 1500 Wire Road, Auburn, Alabama 36849, USA.
| | - R W Waguespack
- Southeastern Veterinary Surgery Center, 3576 Macon Rd., Columbus, Georgia 31907, USA
| | - D D Schwartz
- Department of Anatomy, Physiology, and Pharmacology, Auburn University College of Veterinary Medicine, 1500 Wire Road, Auburn, Alabama 36849, USA
| | - C S Venugopal
- Equine Health Studies Program, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, Louisiana 70803, USA
| | - S C Eades
- Equine Health Studies Program, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, Louisiana 70803, USA
| | - R E Beadle
- Equine Health Studies Program, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, Louisiana 70803, USA
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The effect of tumour necrosis factor-α and insulin on equine digital blood vessel function in vitro. Inflamm Res 2014; 63:637-47. [PMID: 24764104 DOI: 10.1007/s00011-014-0736-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/21/2014] [Accepted: 04/08/2014] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVE AND DESIGN Insulin and inflammatory cytokines may be involved in equine laminitis, which might be associated with digital vascular dysfunction. This study determined the effects of TNF-α and insulin on the endothelial-dependent relaxant responses of equine digital blood vessels and on equine digital vein endothelial cell (EDVEC) cGMP production. MATERIAL Isolated rings of equine digital arteries (EDAs) and veins (EDVs) were obtained and EDVECs were cultured from horses euthanized at an abattoir. METHODS The effect of incubation with TNF-α (10 ng/ml) and/or insulin (1,000 μIU/ml) for 1.5 h or overnight under hyperoxic and hypoxic conditions on carbachol (endothelium-dependent) induced relaxation was assessed. The time course and concentration dependency of the effect of TNF-α and the effect of insulin (1,000 μIU/ml) on EDVEC cGMP production was determined. RESULTS Incubation of EDAs overnight with TNF-α under hypoxic conditions resulted in endothelial-dependent vascular dysfunction. EDVs produced a more variable response. TNF-α increased EDVEC cGMP formation in a time- and concentration-dependent manner. Insulin had no significant effects. CONCLUSIONS There is a mismatch between the results obtained from isolated vessel rings and cultured endothelial cells suggesting TNF-α may reduce the biological effect of NO by reducing its bioavailability rather than its formation, leading to endothelial cell dysregulation.
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Burns TA, Watts MR, Weber PS, McCutcheon LJ, Geor RJ, Belknap JK. Effect of dietary nonstructural carbohydrate content on activation of 5'-adenosine monophosphate-activated protein kinase in liver, skeletal muscle, and digital laminae of lean and obese ponies. J Vet Intern Med 2014; 28:1280-8. [PMID: 24750267 PMCID: PMC4857936 DOI: 10.1111/jvim.12356] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/13/2013] [Accepted: 03/05/2014] [Indexed: 01/16/2023] Open
Abstract
Background In EMS‐associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5′‐Adenosine‐monophosphate‐activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR. Hypothesis/Objectives To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge. Animals Twenty‐two mixed‐breed ponies. Methods Immunohistochemistry and immunoblotting for total AMPK and phospho(P)‐AMPK and RT‐qPCR for AMPK‐responsive genes were performed on laminar, liver, and skeletal muscle samples collected after a 7‐day feeding protocol in which ponies stratified on body condition score (BCS; obese or lean) were fed either a low‐CHO diet (ESC + starch, approximately 7% DM; n = 5 obese, 5 lean) or a high‐CHO diet (ESC + starch, approximately 42% DM; n = 6 obese, 6 lean). Results 5′‐Adenosine‐monophosphate‐activated protein kinase was immunolocalized to laminar keratinocytes, dermal constituents, and hepatocytes. A high‐CHO diet resulted in significantly decreased laminar [P‐AMPK] in lean ponies (P = .03), but no changes in skeletal muscle (lean, P = .33; obese, P = .43) or liver (lean, P = .84; obese, P = .13) [P‐AMPK]. An inverse correlation existed between [blood glucose] and laminar [P‐AMPK] in obese ponies on a high‐CHO diet. Conclusions and Clinical Importance Laminar tissue exhibited a normal response to a high‐CHO diet (decreased [P‐AMPK]), whereas this response was not observed in liver and skeletal muscle in both lean (skeletal muscle, P = .33; liver, P = .84) and obese (skeletal muscle, P = .43; liver, P = .13) ponies.
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Affiliation(s)
- T A Burns
- The Ohio State University College of Veterinary Medicine, Columbus, OH
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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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Sojka-Kritchevsky JE, Johnson PJ. Current status and future directions: Equine pituitary pars intermedia dysfunction and equine metabolic syndrome. Equine Vet J 2013; 46:99-102. [DOI: 10.1111/evj.12194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
| | - P. J. Johnson
- Veterinary Medicine and Surgery; University of Missouri; Columbia USA
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Frank N, Geor R. Current best practice in clinical management of equine endocrine patients. EQUINE VET EDUC 2013. [DOI: 10.1111/eve.12130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- N. Frank
- Clinical Sciences; Tufts Cummings School of Veterinary Medicine; North Grafton Massachusetts USA
- Division of Medicine; School of Veterinary Medicine and Science; University of Nottingham; Leicestershire UK
| | - R. Geor
- Large Animal Clinical Sciences; Michigan State University; East Lansing USA
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Marr CM, Mair TS. EVEandEVJonline collection of equine endocrinology: Recent and future directions; a great start but still a long way to go. EQUINE VET EDUC 2013. [DOI: 10.1111/eve.12142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Katz LM, Bailey SR. A review of recent advances and current hypotheses on the pathogenesis of acute laminitis. Equine Vet J 2013; 44:752-61. [PMID: 23106629 DOI: 10.1111/j.2042-3306.2012.00664.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
With the increasing number of studies being published on the different experimental models used to induce and study acute laminitis, the pathophysiological events associated with these various models (i.e. starch overload, oligofructose overload, black walnut extract and hyperinsulinaemia) can be compared more realistically. Within this review, the mechanisms for metabolic vs. inflammatory laminitis are discussed, and the question of how pasture laminitis may fit into any of the proposed mechanisms is addressed.
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Affiliation(s)
- L M Katz
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland.
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Gauff F, Patan-Zugaj B, Licka TF. Hyperinsulinaemia increases vascular resistance and endothelin-1 expression in the equine digit. Equine Vet J 2013; 45:613-8. [PMID: 23489109 DOI: 10.1111/evj.12040] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 12/05/2012] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY Insulin leads to overexpression of endothelin-1 (ET-1) in the endothelium of insulin-resistant rodents. If this is also the case in equine laminar tissue, this could explain the predisposition of insulin-resistant horses to laminitis. OBJECTIVES To investigate the effect of hyperinsulinaemia on metabolism and vascular resistance of the isolated equine digit in a model of extracorporeal perfusion. STUDY DESIGN Randomised, controlled study with interventional group, with blinded evaluation of histology results. METHOD After exsanguination, equine digits (n = 11) and autologous blood were collected at an abattoir. One digit served as a hyperinsulinaemic pilot limb, 5 digits were assigned to the hyperinsulinaemic perfusion (IP) group and 5 to the control perfusion (CP) group. Digits were perfused for 10 h at a defined perfusion rate of 12 ml/min/kg. After the first hour of perfusion (equilibration period), insulin was added to the reservoir of the IP digits. Perfusion pressure, glucose consumption, lactate and lactate dehydrogenase were monitored. Vascular resistance was calculated as perfusion pressure (in millimetres of mercury) in relation to the flow rate (in millilitres per minute). After perfusion, histology samples of the dorsal hoof wall (haematoxylin & eosin or periodic acid-Schiff) were evaluated. Immunohistology with a polyclonal rabbit-derived anti-endothelin antibody was used for detection of ET-1. RESULTS In the IP group, the mean insulin concentration in the plasma of the perfusate was 142 ± 81 μiu/ml, while insulin concentration was <3 μiu/ml in the CP group. Mean vascular resistance was significantly higher (P<0.01) in the IP group (2.04 ± 1.13 mmHg/ml/min) than in the CP group (1.31 ± 0.55 mmHg/ml/min). Histology of the IP group samples showed significantly more vessels with an open lumen, increased width of the secondary epidermal lamellae and formation of oedema. In the lamellar vessels (veins and arteries) and nerve fibres, ET-1 expression was much more prominent in the IP group than in the CP group samples. CONCLUSIONS Short-term hyperinsulinaemia leads to increased vascular resistance in the equine digit and increased expression of ET-1 in the laminar tissue.
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Affiliation(s)
- F Gauff
- Clinic of Orthopaedics in Large Animals, Department of Horses and Small Animals, Vienna University of Veterinary Medicine, Austria.
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Carmona JU, López C, Samudio IJ. Autologous Platelet Concentrates as an Adjunctive Treatment for Chronic Laminitis in a Mare with Pituitary Pars Intermedia Dysfunction. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2012.05.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Affiliation(s)
- N. Menzies-Gow
- Department of Veterinary Clinical Science; Royal Veterinary College; North Mymms; UK
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Keen JA, McGorum BC, Hillier C, Nally JE. Short-term incubation of equine laminar veins with cortisol and insulin alters contractility in vitro: possible implications for the pathogenesis of equine laminitis. J Vet Pharmacol Ther 2012; 36:382-8. [PMID: 22943152 DOI: 10.1111/j.1365-2885.2012.01429.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 07/07/2012] [Indexed: 11/25/2022]
Abstract
This study investigated the effects of cortisol and insulin, hormones that affect both glycaemic status and vascular function, on the in vitro contractility of isolated healthy equine small laminar veins. Small veins (150-500 μm) draining the digital laminae from healthy horses or ponies were investigated by wire myography. Concentration response curves were constructed for noradrenaline (NA), phenylephrine (PE), endothelin-1 (ET-1) and 5-hydroxytryptamine (5-HT) in the presence of either cortisol (10(-6 ) m) or insulin (1000 μIU/mL). Cortisol significantly increased the maximum contractility of laminar veins to the vasoconstrictors NA and 5-HT but decreased the maximal contraction to ET-1. Insulin decreased the contractility of vessels to PE and ET-1. It is possible that short-term cortisol excess could enhance venoconstrictor responses to 5-HT and NA in laminar veins in vivo, thereby predisposing to laminitis. Additionally, a reduction in the ability of insulin to counteract alpha-adrenoreceptor and ET-1-mediated contraction, likely to occur in subjects with insulin resistance, may further exacerbate venoconstriction in animals prone to laminitis. These mechanisms may also predispose horses with disorders such as equine Cushing's disease and equine metabolic syndrome to laminitis.
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Affiliation(s)
- J A Keen
- Department of Biological and Biochemical Science, Glasgow Caledonian University, Glasgow, UK.
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Burns TA, Watts MR, Weber PS, Mccutcheon LJ, Geor RJ, Belknap JK. Distribution of insulin receptor and insulin-like growth factor-1 receptor in the digital laminae of mixed-breed ponies: An immunohistochemical study. Equine Vet J 2012; 45:326-32. [DOI: 10.1111/j.2042-3306.2012.00631.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Lacombe VA. Glucose metabolism in insulin-sensitive tissue: from health to disease and Glucose Transport in Adipose Tissue: Novel Insights into the Pathogenesis of Insulin Resistance. J Equine Vet Sci 2011. [DOI: 10.1016/j.jevs.2011.09.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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