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Bornstein MR, Tian R, Arany Z. Human cardiac metabolism. Cell Metab 2024; 36:1456-1481. [PMID: 38959861 PMCID: PMC11290709 DOI: 10.1016/j.cmet.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/12/2024] [Accepted: 06/05/2024] [Indexed: 07/05/2024]
Abstract
The heart is the most metabolically active organ in the human body, and cardiac metabolism has been studied for decades. However, the bulk of studies have focused on animal models. The objective of this review is to summarize specifically what is known about cardiac metabolism in humans. Techniques available to study human cardiac metabolism are first discussed, followed by a review of human cardiac metabolism in health and in heart failure. Mechanistic insights, where available, are reviewed, and the evidence for the contribution of metabolic insufficiency to heart failure, as well as past and current attempts at metabolism-based therapies, is also discussed.
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Affiliation(s)
- Marc R Bornstein
- Cardiovascular Institute Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Rong Tian
- Mitochondria and Metabolism Center, Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA, USA
| | - Zoltan Arany
- Cardiovascular Institute Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Holm J, Vanky F, Svedjeholm R. Association of Glutamate Infusion With Risk of Acute Kidney Injury After Coronary Artery Bypass Surgery: A Pooled Analysis of 2 Randomized Clinical Trials. JAMA Netw Open 2024; 7:e2351743. [PMID: 38252440 PMCID: PMC10804267 DOI: 10.1001/jamanetworkopen.2023.51743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 11/27/2023] [Indexed: 01/23/2024] Open
Abstract
Importance Acute kidney injury (AKI) after cardiac surgery is associated with increased morbidity and mortality, and measures to prevent AKI have had limited success. Glutamate has been reported to enhance natural postischemic recovery of the heart, but not among animals and humans with diabetes. Objective To summarize pooled results from the GLUTAMICS (Glutamate for Metabolic Intervention in Coronary Surgery) trials regarding the effect of glutamate on postoperative AKI among patients without diabetes undergoing coronary artery bypass graft (CABG) surgery. Design, Setting, and Participants Data on a total of 791 patients without diabetes from 2 prospective, randomized, double-blind multicenter trials performed at 5 cardiac surgery centers in Sweden between October 4, 2005, and November 12, 2009, and between November 15, 2015, and September 30, 2020, were pooled. Patients had acute coronary syndrome, left ventricular ejection fraction of 0.30 or less, or a European System for Cardiac Risk Evaluation II score of 3.0 or more and underwent CABG with or without additional valve procedure. Statistical analysis was performed from May to November 2023. Interventions Intravenous infusion of 0.125-M l-glutamic acid or saline at 1.65 mL/kg/h for 2 hours during reperfusion, after which the infusion rate was halved and an additional 50 mL was given. Main Outcomes and Measures The primary end point was AKI, defined as postoperative increase of plasma creatinine of 50% or more, corresponding to the Risk stage or higher in the Risk, Injury, Failure, Loss, and End-Stage kidney disease (RIFLE) criteria. Results A total of 791 patients without diabetes (391 who received glutamate [mean (SD) age, 69.3 (9.1) years; 62 women (15.9%)] and 400 controls [mean (SD) age, 69.6 (9.5) years; 73 women (18.3%)]) were randomized. Baseline data did not differ between groups. Glutamate was associated with a significantly lower risk of AKI (relative risk, 0.49 [95% CI, 0.29-0.83]). Dialysis was required for 2 patients in the glutamate group and 5 patients in the control group. In multivariable analysis, glutamate remained significantly associated with a protective effect against AKI (odds ratio, 0.47 [95% CI, 0.26-0.86]). In the glutamate and control groups, the rate of postoperative mortality at 30 days or less was 0.5% (2 of 391) vs 1.0% (4 of 400), and the rate of stroke at 24 hours or less was 0.8% (3 of 391) vs 1.8% (7 of 400). Conclusions and Relevance In this pooled analysis of 2 randomized clinical trials, infusion of glutamate was associated with a markedly lower risk of AKI after CABG among patients without diabetes. The findings are exploratory and need to be confirmed in prospective trials. Trial Registration ClinicalTrials.gov Identifiers: NCT00489827 and NCT02592824.
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Affiliation(s)
- Jonas Holm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
| | - Farkas Vanky
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
| | - Rolf Svedjeholm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
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Huang X, Zhao JV. The Associations of Genetically Predicted Plasma Alanine with Coronary Artery Disease and its Risk Factors: A Mendelian Randomization Study. Am J Clin Nutr 2023; 118:1020-1028. [PMID: 37640107 DOI: 10.1016/j.ajcnut.2023.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND Alanine is an amino acid commonly used as a nutritional supplement and plays a key role in the glucose-alanine cycle. Plasma alanine has been associated in observational studies with a higher risk of coronary artery disease (CAD) and unhealthier lipid profiles. However, evidence from large randomized controlled trials is lacking. OBJECTIVES Using Mendelian randomization (MR), we assessed the unconfounded associations of plasma alanine with CAD and CAD risk factors. METHODS We applied single nucleotide polymorphisms that were strongly (P < 5 ×10-8) associated with plasma alanine as genetic instruments to large genome-wide association studies of CAD (63,108 cases; 296,901 controls), diabetes (90,612 cases; 583,493 controls), glucose (515,538 participants), lipids (low-density lipoprotein [LDL] cholesterol, high-density lipoprotein [HDL] cholesterol, triglycerides, total cholesterol, and apolipoprotein B) (>1.1 million participants), blood pressure (BP) (757,601 participants), and body mass index (682,137 participants). Given the potential sex disparity, we also conducted sex-specific analyses. MR estimates per standard deviation increase in alanine concentrations were obtained using inverse variance weighting followed by sensitivity analyses using weighted median, MR-Egger, MR-Pleiotropy RESidual Sum and Outlier, and MR-Robust Adjusted Profile Score. RESULTS Genetically predicted plasma alanine was not associated with CAD but with a higher risk of diabetes (odds ratio [OR]: 1.35; 95% confidence interval [CI]: 1.06, 1.72), higher glucose (β: 0.11; 95% CI: 0.02, 0.19), LDL cholesterol (β: 0.08; 95% CI: 0.04, 0.12), triglycerides (β: 0.25; 95% CI: 0.13, 0.38), total cholesterol (β: 0.14; 95% CI: 0.08, 0.20), apolipoprotein B (β: 0.12; 95% CI: 0.03, 0.21), and BP (β: 1.17; 95% CI: 0.31, 2.04 for systolic BP: β: 0.97; 95% CI: 0.49, 1.45 for diastolic BP) overall. The positive associations of serum alanine with LDL cholesterol and triglycerides were more notable in women than in men. CONCLUSIONS Alanine or factors affecting alanine may have causal effects on diabetes, blood glucose, lipid profiles, and BP but not on CAD. Further studies are needed to clarify possible mechanisms.
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Affiliation(s)
- Xin Huang
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jie V Zhao
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
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Svedjeholm R, Ferrari G, Vanky F, Friberg Ö, Holm J. Glutamate infusion associated with reduced rises of p-Copeptin after coronary surgery: Substudy of GLUTAMICS II. Acta Anaesthesiol Scand 2023; 67:1373-1382. [PMID: 37365871 DOI: 10.1111/aas.14303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/25/2023] [Accepted: 06/03/2023] [Indexed: 06/28/2023]
Abstract
BACKGROUND Glutamate plays a key role for post-ischaemic recovery of myocardial metabolism. According to post hoc analyses of the two GLUTAMICS trials, patients without diabetes benefit from glutamate with less myocardial dysfunction after coronary artery bypass surgery (CABG). Copeptin reflects activation of the Arginine Vasopressin system and is a reliable marker of heart failure but available studies in cardiac surgery are limited. We investigated whether glutamate infusion is associated with reduced postoperative rises of plasma Copeptin (p-Copeptin) after CABG. METHODS A prespecified randomised double-blind substudy of GLUTAMICS II. Patients had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0 and underwent CABG ± valve procedure. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h was commenced 10-20 min before the release of the aortic cross-clamp and then continued for another 150 min P-Copeptin was measured preoperatively and postoperatively on day one (POD1) and day three. The primary endpoint was an increase in p-Copeptin from the preoperative level to POD1. Postoperative stroke ≤24 h and mortality ≤30 days were safety outcomes. RESULTS We included 181 patients of whom 48% had diabetes. The incidence of postoperative mortality ≤30 days (0% vs. 2.1%; p = .50) and stroke ≤24 h (0% vs. 3.2%; p = .25) did not differ between the glutamate group and controls. P-Copeptin increased postoperatively with the highest values recorded on POD1 without significant inter-group differences. Among patients without diabetes, p-Copeptin did not differ preoperatively but postoperative rise from preoperative level to POD1 was significantly reduced in the glutamate group (73 ± 66 vs. 115 ± 102 pmol/L; p = .02). P-Copeptin was significantly lower in the Glutamate group on POD1 (p = .02) and POD 3 (p = .02). CONCLUSIONS Glutamate did not reduce rises of p-Copeptin significantly after moderate to high-risk CABG. However, glutamate was associated with reduced rises of p-Copeptin among patients without diabetes. These results agree with previous observations suggesting that glutamate mitigates myocardial dysfunction after CABG in patients without diabetes. Given the exploratory nature of these findings, they need to be confirmed in future studies.
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Affiliation(s)
- Rolf Svedjeholm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
| | - Gabriele Ferrari
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Health Care Research Centre, Örebro University, Örebro, Sweden
| | - Farkas Vanky
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
| | - Örjan Friberg
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Health Care Research Centre, Örebro University, Örebro, Sweden
| | - Jonas Holm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
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Holm J, Vanky F, Svedjeholm R. Glutamate Infusion Reduces Myocardial Dysfunction after Coronary Artery Bypass Grafting According to NT-proBNP: Summary of 2 Randomized Controlled Trials (GLUTAmate for Metabolic Intervention in Coronary Surgery [GLUTAMICS I-II]). Am J Clin Nutr 2023; 118:930-937. [PMID: 37657522 DOI: 10.1016/j.ajcnut.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/14/2023] [Accepted: 08/24/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Glutamate is reported to enhance the recovery of oxidative metabolism and contractile function of the heart after ischemia. The effect appears to be blunted in diabetic hearts. Elevated plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) reflects myocardial dysfunction. In the GLUTAmate for Metabolic Intervention in Coronary Surgery (GLUTAMICS) II trial, the proportion of patients with diabetes had nearly doubled to 47% compared with the cohort used for sample size estimation, and a significant effect on the postoperative rise in NT-proBNP was only observed in patients without diabetes. OBJECTIVE We aimed to summarize the pooled NT-proBNP results from both GLUTAMICS trials and address the impact of diabetes. METHODS Data from 2 prospective, randomized, double-blind multicenter trials with similar inclusion criteria and endpoints were pooled. Patients underwent a coronary artery bypass grafting (CABG) ± valve procedure and had a left-ventricular ejection fraction of ≤0.30 or a European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) of ≥3.0 with at least 1 cardiac risk factor. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h was started 10-20 min before reperfusion and continued for 150 min. The primary endpoint was the difference between preoperative and day 3 postoperative NT-proBNP levels. RESULTS A total of 451 patients, 224 receiving glutamate and 227 controls, fulfilled the inclusion criteria. Glutamate was associated with a reduced primary endpoint (5344 ± 5104 ng/L and 6662 ± 5606 ng/L in glutamate and control groups, respectively; P = 0.01). Postoperative mortality at ≤30 d was 0.9% and 3.5% (P = 0.11), whereas stroke at ≤24 h was 0.4% and 2.6% in glutamate and control groups, respectively (P = 0.12). No adverse events related to glutamate were observed. A significant interaction regarding the primary endpoint was only detected between glutamate and insulin-treated diabetes groups (P = 0.04). Among patients without insulin-treated diabetes, the primary endpoint was 5047 ± 4705 ng/L and 7001 ± 5830 ng/L in the glutamate and control groups, respectively (P = 0.001). CONCLUSIONS Infusion of glutamate reduced the postoperative rise in NT-proBNP after CABG in medium- to high-risk patients. A significantly blunted effect was observed only in insulin-treated patients with diabetes. CLINICAL TRIAL DETAILS This trial was registered at www. CLINICALTRIALS gov as NCT02592824.
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Affiliation(s)
- Jonas Holm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Sweden
| | - Farkas Vanky
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Sweden
| | - Rolf Svedjeholm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Sweden.
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Safari-Alighiarloo N, Mani-Varnosfaderani A, Madani NH, Tabatabaei SM, Babaei MR, Khamseh ME. Potential metabolic biomarkers of critical limb ischemia in people with type 2 diabetes mellitus. Metabolomics 2023; 19:66. [PMID: 37452163 DOI: 10.1007/s11306-023-02029-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/29/2023] [Indexed: 07/18/2023]
Abstract
INTRODUCTION Type 2 diabetes mellitus (T2DM) is a significant risk factor for the development of critical limb ischemia (CLI), the most advanced stage of peripheral arterial disease. The concurrent existence of T2DM and CLI often leads to adverse outcomes, namely limb amputation. OBJECTIVE To identify biomarkers for improving the screening of CLI in high-risk people with T2DM. METHODS We investigated metabolome profiles in serum samples of 113 T2DM people with CLI (n = 23, G2) and without CLI (n = 45, G0: no lower limb stenosis (LLS) and n = 45, G1: LLS < 50%), using hydrogen nuclear magnetic resonance (1H NMR) approach. Principle component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used to analyze 1H NMR data. RESULTS Twenty potential metabolites that could discriminate people with T2DM and CLI (G2) from non-CLI patients without LLS (G0) were determined in serum samples. The correct percent of classification for the PLS-DA model for the test set samples was 85% (n = 20) and 100% (n = 5) for G0 and G2 groups, respectively. Non-CLI patients with LLS < 50% (G1) were projected on the PCA abstract space built using 20 discriminatory metabolites. Eleven people with T2DM and LLS < 50% were prospectively followed, and their ankle-brachial index (ABI) was measured after 4 years. A promising agreement existed between the PCA model's predictions and those obtained by ABI values. CONCLUSION The findings suggest that confirmation of blood potential metabolic biomarkers as a complement to ABI for screening of CLI in a large group of high-risk people with T2DM is needed.
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Affiliation(s)
- Nahid Safari-Alighiarloo
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran.
- Endocrine and Metabolism Research Institute, Firoozeh Alley, Valiasr Square, Tehran, Iran.
| | - Ahmad Mani-Varnosfaderani
- Chemometrics and Cheminformatics Laboratory, Department of Chemistry, Tarbiat Modares University, Tehran, Iran.
| | - Nahid Hashemi Madani
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran
| | - Seyyed Mohammad Tabatabaei
- Medical Informatics Department, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Reza Babaei
- Department of Interventional Radiology, Firouzgar Hospital, Iran University of Medical Science, Tehran, Iran
| | - Mohammad E Khamseh
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran
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Metabolomic Profiling in Patients with Different Hemodynamic Subtypes of Severe Aortic Valve Stenosis. Biomolecules 2023; 13:biom13010095. [PMID: 36671480 PMCID: PMC9855798 DOI: 10.3390/biom13010095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/16/2022] [Accepted: 12/26/2022] [Indexed: 01/05/2023] Open
Abstract
Severe aortic stenosis (AS) is a common pathological condition in an ageing population imposing significant morbidity and mortality. Based on distinct hemodynamic features, i.e., ejection fraction (EF), transvalvular gradient and stroke volume, four different AS subtypes can be distinguished: (i) normal EF and high gradient, (ii) reduced EF and high gradient, (iii) reduced EF and low gradient, and (iv) normal EF and low gradient. These subtypes differ with respect to pathophysiological mechanisms, cardiac remodeling, and prognosis. However, little is known about metabolic changes in these different hemodynamic conditions of AS. Thus, we carried out metabolomic analyses in serum samples of 40 AS patients (n = 10 per subtype) and 10 healthy blood donors (controls) using ultrahigh-performance liquid chromatography-tandem mass spectroscopy. A total of 1293 biochemicals could be identified. Principal component analysis revealed different metabolic profiles in all of the subgroups of AS (All-AS) vs. controls. Out of the determined biochemicals, 48% (n = 620) were altered in All-AS vs. controls (p < 0.05). In this regard, levels of various acylcarnitines (e.g., myristoylcarnitine, fold-change 1.85, p < 0.05), ketone bodies (e.g., 3-hydroxybutyrate, fold-change 11.14, p < 0.05) as well as sugar metabolites (e.g., glucose, fold-change 1.22, p < 0.05) were predominantly increased, whereas amino acids (e.g., leucine, fold-change 0.8, p < 0.05) were mainly reduced in All-AS. Interestingly, these changes appeared to be consistent amongst all AS subtypes. Distinct differences between AS subtypes were found for metabolites belonging to hemoglobin metabolism, diacylglycerols, and dihydrosphingomyelins. These findings indicate that relevant changes in substrate utilization appear to be consistent for different hemodynamic subtypes of AS and may therefore reflect common mechanisms during AS-induced heart failure. Additionally, distinct metabolites could be identified to significantly differ between certain AS subtypes. Future studies need to define their pathophysiological implications.
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Holm J, Ferrari G, Holmgren A, Vanky F, Friberg Ö, Vidlund M, Svedjeholm R. Effect of glutamate infusion on NT-proBNP after coronary artery bypass grafting in high-risk patients (GLUTAMICS II): A randomized controlled trial. PLoS Med 2022; 19:e1003997. [PMID: 35533197 PMCID: PMC9126383 DOI: 10.1371/journal.pmed.1003997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/23/2022] [Accepted: 04/22/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Animal and human data suggest that glutamate can enhance recovery of myocardial metabolism and function after ischemia. N-terminal pro-brain natriuretic peptide (NT-proBNP) reflects myocardial dysfunction after coronary artery bypass surgery (CABG). We investigated whether glutamate infusion can reduce rises of NT-proBNP in moderate- to high-risk patients after CABG. METHODS AND FINDINGS A prospective, randomized, double-blind study enrolled patients from November 15, 2015 to September 30, 2020, with a 30-day follow-up at 4 academic cardiac surgery centers in Sweden. Patients underwent CABG ± valve procedure and had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h started 10 to 20 minutes before releasing the aortic cross-clamp, then continued for another 150 minutes. Patients, staff, and investigators were blinded to the treatment. The primary endpoint was the difference between preoperative and day-3 postoperative NT-proBNP levels. Analysis was intention to treat. We studied 303 patients (age 74 ± 7 years; females 26%, diabetes 47%), 148 receiving glutamate group and 155 controls. There was no significant difference in the primary endpoint associated with glutamate administration (5,390 ± 5,396 ng/L versus 6,452 ± 5,215 ng/L; p = 0.086). One patient died ≤30 days in the glutamate group compared to 6 controls (0.7% versus 3.9%; p = 0.12). No adverse events linked to glutamate were observed. A significant interaction between glutamate and diabetes was found (p = 0.03). Among patients without diabetes the primary endpoint (mean 4,503 ± 4,846 ng/L versus 6,824 ± 5,671 ng/L; p = 0.007), and the incidence of acute kidney injury (11% versus 29%; p = 0.005) was reduced in the glutamate group. These associations remained significant after adjusting for differences in baseline data. The main limitations of the study are: (i) it relies on a surrogate marker for heart failure; and (ii) the proportion of patients with diabetes had almost doubled compared to the cohort used for the sample size estimation. CONCLUSIONS Infusion of glutamate did not significantly reduce postoperative rises of NT-proBNP. Diverging results in patients with and without diabetes agree with previous observations and suggest that the concept of enhancing postischemic myocardial recovery with glutamate merits further evaluation. TRIAL REGISTRATION ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT02592824. European Union Drug Regulating Authorities Clinical Trials Database (Eudra CT number 2011-006241-15).
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Affiliation(s)
- Jonas Holm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
| | - Gabriele Ferrari
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Health Care Research Center, Örebro University, Örebro, Sweden
| | - Anders Holmgren
- Heart Center and Department of Public Health and Clinical Medicine, Medicine, Umeå University, Umeå, Sweden
| | - Farkas Vanky
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
| | - Örjan Friberg
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Health Care Research Center, Örebro University, Örebro, Sweden
| | - Mårten Vidlund
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Health Care Research Center, Örebro University, Örebro, Sweden
- Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Rolf Svedjeholm
- Department of Thoracic and Vascular Surgery, Department of Health, Medicine and Caring Sciences, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden
- * E-mail:
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Berndt N, Eckstein J, Wallach I, Nordmeyer S, Kelm M, Kirchner M, Goubergrits L, Schafstedde M, Hennemuth A, Kraus M, Grune T, Mertins P, Kuehne T, Holzhütter HG. CARDIOKIN1: Computational Assessment of Myocardial Metabolic Capability in Healthy Controls and Patients With Valve Diseases. Circulation 2021; 144:1926-1939. [PMID: 34762513 PMCID: PMC8663543 DOI: 10.1161/circulationaha.121.055646] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. Background: Many heart diseases can result in reduced pumping capacity of the heart muscle. A mismatch between ATP demand and ATP production of cardiomyocytes is one of the possible causes. Assessment of the relation between myocardial ATP production (MVATP) and cardiac workload is important for better understanding disease development and choice of nutritional or pharmacologic treatment strategies. Because there is no method for measuring MVATP in vivo, the use of physiology-based metabolic models in conjunction with protein abundance data is an attractive approach. METHOD: We developed a comprehensive kinetic model of cardiac energy metabolism (CARDIOKIN1) that recapitulates numerous experimental findings on cardiac metabolism obtained with isolated cardiomyocytes, perfused animal hearts, and in vivo studies with humans. We used the model to assess the energy status of the left ventricle of healthy participants and patients with aortic stenosis and mitral valve insufficiency. Maximal enzyme activities were individually scaled by means of protein abundances in left ventricle tissue samples. The energy status of the left ventricle was quantified by the ATP consumption at rest (MVATP[rest]), at maximal workload (MVATP[max]), and by the myocardial ATP production reserve, representing the span between MVATP(rest) and MVATP(max). Results: Compared with controls, in both groups of patients, MVATP(rest) was increased and MVATP(max) was decreased, resulting in a decreased myocardial ATP production reserve, although all patients had preserved ejection fraction. The variance of the energetic status was high, ranging from decreased to normal values. In both patient groups, the energetic status was tightly associated with mechanic energy demand. A decrease of MVATP(max) was associated with a decrease of the cardiac output, indicating that cardiac functionality and energetic performance of the ventricle are closely coupled. Conclusions: Our analysis suggests that the ATP-producing capacity of the left ventricle of patients with valvular dysfunction is generally diminished and correlates positively with mechanical energy demand and cardiac output. However, large differences exist in the energetic state of the myocardium even in patients with similar clinical or image-based markers of hypertrophy and pump function. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03172338 and NCT04068740.
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Affiliation(s)
- Nikolaus Berndt
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Johannes Eckstein
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Biochemistry, Charitá - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Iwona Wallach
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Biochemistry, Charitá - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sarah Nordmeyer
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Department of Congenital Heart Disease - Pediatric Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany
| | - Marcus Kelm
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Department of Congenital Heart Disease - Pediatric Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung e. V. (DZHK), Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany
| | - Marieluise Kirchner
- Berlin Institute of Health (BIH), Berlin, Germany; Proteomics Platform, Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Leonid Goubergrits
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Einstein Center Digital Future, Berlin, Germany
| | - Marie Schafstedde
- Institute of Computer-assisted Cardiovascular Medicine, Charité; Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Department of Congenital Heart Disease - Pediatric Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany
| | - Anja Hennemuth
- Institute of Computer-assisted Cardiovascular Medicine, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Milena Kraus
- Digital Health Center, Hasso Plattner Institute, University of Potsdam, Germany
| | - Tilman Grune
- Deutsches Zentrum für Herz-Kreislauf-Forschung e. V. (DZHK), Berlin, Germany; Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - Philipp Mertins
- Berlin Institute of Health (BIH), Berlin, Germany; Proteomics Platform, Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Titus Kuehne
- Institute of Computer-assisted Cardiovascular Medicine, Charité; Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Department of Congenital Heart Disease - Pediatric Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung e. V. (DZHK), Berlin, Germany
| | - Hermann-Georg Holzhütter
- Institute of Biochemistry, Charitá - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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Müller J, Bertsch T, Volke J, Schmid A, Klingbeil R, Metodiev Y, Karaca B, Kim SH, Lindner S, Schupp T, Kittel M, Poschet G, Akin I, Behnes M. Narrative review of metabolomics in cardiovascular disease. J Thorac Dis 2021; 13:2532-2550. [PMID: 34012599 PMCID: PMC8107570 DOI: 10.21037/jtd-21-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cardiovascular diseases are accompanied by disorders in the cardiac metabolism. Furthermore, comorbidities often associated with cardiovascular disease can alter systemic and myocardial metabolism contributing to worsening of cardiac performance and health status. Biomarkers such as natriuretic peptides or troponins already support diagnosis, prognosis and treatment of patients with cardiovascular diseases and are represented in international guidelines. However, as cardiovascular diseases affect various pathophysiological pathways, a single biomarker approach cannot be regarded as ideal to reveal optimal clinical application. Emerging metabolomics technology allows the measurement of hundreds of metabolites in biological fluids or biopsies and thus to characterize each patient by its own metabolic fingerprint, improving our understanding of complex diseases, significantly altering the management of cardiovascular diseases and possibly personalizing medicine. This review outlines current knowledge, perspectives as well as limitations of metabolomics for diagnosis, prognosis and treatment of cardiovascular diseases such as heart failure, atherosclerosis, ischemic and non-ischemic cardiomyopathy. Furthermore, an ongoing research project tackling current inconsistencies as well as clinical applications of metabolomics will be discussed. Taken together, the application of metabolomics will enable us to gain more insights into pathophysiological interactions of metabolites and disease states as well as improving therapies of patients with cardiovascular diseases in the future.
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Affiliation(s)
- Julian Müller
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Thomas Bertsch
- Institute of Clinical Chemistry, Laboratory Medicine and Transfusion Medicine, Nuremburg General Hospital, Paracelsus Medical University, Nuremberg, Germany
| | - Justus Volke
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Alexander Schmid
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Rebecca Klingbeil
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Yulian Metodiev
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Bican Karaca
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Seung-Hyun Kim
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Simon Lindner
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Tobias Schupp
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Maximilian Kittel
- Institute for Clinical Chemistry, Faculty of Medicine Mannheim, Heidelberg University, Mannheim, Germany
| | - Gernot Poschet
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany
| | - Ibrahim Akin
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
| | - Michael Behnes
- First Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany
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11
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The impact of glutamate infusion on postoperative NT-proBNP in patients undergoing coronary artery bypass surgery: a randomized study. J Transl Med 2020; 18:193. [PMID: 32393387 PMCID: PMC7216679 DOI: 10.1186/s12967-020-02351-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 04/25/2020] [Indexed: 12/28/2022] Open
Abstract
Background Glutamate, a key intermediate in myocardial metabolism, may enhance myocardial recovery after ischemia and possibly reduce the incidence and severity of postoperative heart failure in coronary artery bypass surgery (CABG). N-terminal pro-B-type natriuretic peptide (NT-proBNP) can be used to assess postoperative heart failure (PHF) after CABG. Our hypothesis was that glutamate enhances myocardial recovery in post-ischemic heart failure and, therefore, will be accompanied by a mitigated postoperative increase of NT-proBNP. Methods Substudy of the GLUTAmate for Metabolic Intervention in Coronary Surgery (GLUTAMICS) trial (ClinicalTrials.gov Identifier: NCT00489827) a prospective triple-center double-blind randomized clinical trial on 399 patients undergoing CABG with or without concomitant procedure for acute coronary syndrome at three Swedish Cardiac Surgery centres (Linköping, Örebro, and Karlskrona) from May 30, 2007 to November 12, 2009. Patients were randomly assigned to intravenous infusion of 0.125 M l-glutamic acid or saline (1.65 mL/kg of body weight per hour) intraoperatively and postoperatively. Plasma NT-proBNP was measured preoperatively, the first (POD1) and third postoperative morning (POD3). A Clinical Endpoints Committee, blinded to both intervention and NT-proBNP used prespecified criteria to diagnose PHF. The primary endpoints were the absolute levels of postoperative NT-proBNP and the difference between preoperative and postoperative levels of NT-proBNP. Results Overall no significant difference was detected in postoperative NT-proBNP levels between groups. However, in high-risk patients (upper quartile of EuroSCORE II ≥ 4.15; glutamate group n = 56; control group n = 45) glutamate was associated with significantly lower postoperative increase of NT-proBNP (POD3-Pre: 3900 [2995–6260] vs. 6745 [3455–12,687] ng•L−1, p = 0.012) and lower NT-proBNP POD3 (POD3: 4845 [3426–7423] vs. 8430 [5370–14,100] ng•L−1, p = 0.001). After adjusting for significant differences in preoperative demographics, NT-proBNP POD3 in the glutamate group was 0.62 times of that in the control group (p = 0.002). Patients in the glutamate group also had shorter ICU stay (21 [19–26] vs. 25 [22–46] h, p = 0.025) and less signs of myocardial injury (Troponin T POD3 (300 [170–500] vs. 560 [210–910] ng•L−1, p = 0.025). Conclusions Post hoc analysis of postoperative NT-proBNP suggests that intravenous infusion of glutamate may prevent or mitigate myocardial dysfunction in high-risk patients undergoing CABG. Further studies are necessary to confirm these findings. Trial registration Swedish Medical Products Agency 151:2003/70403 (prospectively registered with amendment about this substudy filed March 17, 2007). ClinicalTrials.gov Identifier: NCT00489827 (retrospectively registered) https://clinicaltrials.gov/ct2/show/NCT00489827?term=glutamics&draw=1&rank=1
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12
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Karlstaedt A, Schiffer W, Taegtmeyer H. Actionable Metabolic Pathways in Heart Failure and Cancer-Lessons From Cancer Cell Metabolism. Front Cardiovasc Med 2018; 5:71. [PMID: 29971237 PMCID: PMC6018530 DOI: 10.3389/fcvm.2018.00071] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 05/24/2018] [Indexed: 12/21/2022] Open
Abstract
Recent advances in cancer cell metabolism provide unprecedented opportunities for a new understanding of heart metabolism and may offer new approaches for the treatment of heart failure. Key questions driving the cancer field to understand how tumor cells reprogram metabolism and to benefit tumorigenesis are also applicable to the heart. Recent experimental and conceptual advances in cancer cell metabolism provide the cardiovascular field with the unique opportunity to target metabolism. This review compares cancer cell metabolism and cardiac metabolism with an emphasis on strategies of cellular adaptation, and how to exploit metabolic changes for therapeutic benefit.
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Affiliation(s)
- Anja Karlstaedt
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Walter Schiffer
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Heinrich Taegtmeyer
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
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13
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Contemporary Advances in Myocardial Metabolic Imaging and Their Impact on Clinical Care: a Focus on Positron Emission Tomography (PET). CURRENT CARDIOVASCULAR IMAGING REPORTS 2018. [DOI: 10.1007/s12410-018-9444-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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14
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Funk AM, Anderson BL, Wen X, Hever T, Khemtong C, Kovacs Z, Sherry AD, Malloy CR. The rate of lactate production from glucose in hearts is not altered by per-deuteration of glucose. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 284:86-93. [PMID: 28972888 PMCID: PMC5817885 DOI: 10.1016/j.jmr.2017.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/13/2017] [Accepted: 09/14/2017] [Indexed: 05/05/2023]
Abstract
This study was designed to determine whether perdeuterated glucose experiences a kinetic isotope effect (KIE) as glucose passes through glycolysis and is further oxidized in the tricarboxylic acid (TCA) cycle. Metabolism of deuterated glucose was investigated in two groups of perfused rat hearts. The control group was supplied with a 1:1 mixture of [U-13C6]glucose and [1,6-13C2]glucose, while the experimental group received [U-13C6,U-2H7]glucose and [1,6-13C2]glucose. Tissue extracts were analyzed by 1H, 2H and proton-decoupled 13C NMR spectroscopy. Extensive 2H-13C scalar coupling plus chemical shift isotope effects were observed in the proton-decoupled 13C NMR spectra of lactate, alanine and glutamate. A small but measureable (∼8%) difference in the rate of conversion of [U-13C6]glucose vs. [1,6-13C2]glucose to lactate, likely reflecting rates of CC bond breakage in the aldolase reaction, but conversion of [U-13C6]glucose versus [U-13C6,U-2H7]glucose to lactate did not differ. This shows that the presence of deuterium in glucose does not alter glycolytic flux. However, there were two distinct effects of deuteration on metabolism of glucose to alanine and oxidation of glucose in the TCA. First, alanine undergoes extensive exchange of methyl deuterons with solvent protons in the alanine amino transferase reaction. Second, there is a substantial kinetic isotope effect in metabolism of [U-13C6,U-2H7]glucose to alanine and glutamate. In the presence of [U-13C6,U-2H7]glucose, alanine and lactate are not in rapid exchange with the same pool of pyruvate. These studies indicate that the appearance of hyperpolarized 13C-lactate from hyperpolarized [U-13C6,U-2H7]glucose is not substantially influenced by a deuterium kinetic isotope effect.
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Affiliation(s)
- Alexander M Funk
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Brian L Anderson
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Xiaodong Wen
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Thomas Hever
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Chalermchai Khemtong
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Zoltan Kovacs
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States; Department of Chemistry, University of Texas at Dallas, Richardson, TX, United States
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States; Veterans Affairs North Texas Healthcare System, Dallas, TX, United States.
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15
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Zhang JY, Kong LH, Lai D, Jin ZX, Gu XM, Zhou JJ. Glutamate protects against Ca(2+) paradox-induced injury and inhibits calpain activity in isolated rat hearts. Clin Exp Pharmacol Physiol 2017; 43:951-9. [PMID: 27279457 DOI: 10.1111/1440-1681.12605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 04/25/2016] [Accepted: 06/02/2016] [Indexed: 01/13/2023]
Abstract
This study determined the effects of glutamate on the Ca(2+) paradoxical heart, which is a model for Ca(2+) overload-induced injury during myocardial ischaemia and reperfusion, and evaluated its effect on a known mediator of injury, calpain. An isolated rat heart was retrogradely perfused in a Langendorff apparatus. Ca(2+) paradox was elicited via perfusion with a Ca(2+) -free Krebs-Henseleit (KH) solution for 3 minutes followed by Ca(2+) -containing normal KH solution for 30 minutes. The Ca(2+) paradoxical heart exhibited almost no viable tissue on triphenyltetrazolium chloride staining and markedly increased LDH release, caspase-3 activity, cytosolic cytochrome c content, and apoptotic index. These hearts also displayed significantly increased LVEDP and a disappearance of LVDP. Glutamate (5 and 20 mmol/L) significantly alleviated Ca(2+) paradox-induced injury. In contrast, 20 mmol/L mannitol had no effect on Ca(2+) paradox. Ca(2+) paradox significantly increased the extent of the translocation of μ-calpain to the sarcolemmal membrane and the proteolysis of α-fodrin, which suggests calpain activation. Glutamate also blocked these effects. A non-selective inhibitor of glutamate transporters, dl-TBOA (10 μmol/L), had no effect on control hearts, but it reversed glutamate-induced cardioprotection and reduction in calpain activity. Glutamate treatment significantly increased intracellular glutamate content in the Ca(2+) paradoxical heart, which was also blocked by dl-TBOA. We conclude that glutamate protects the heart against Ca(2+) overload-induced injury via glutamate transporters, and the inhibition of calpain activity is involved in this process.
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Affiliation(s)
- Jian-Ying Zhang
- Department of Physiology, The Fourth Military Medical University, Xi'an, China
| | - Ling-Heng Kong
- Department of Physiology, The Fourth Military Medical University, Xi'an, China.,Institute of Basic Medical Science, Xi'an Medical College, Xi'an, China
| | - Dong Lai
- Department of Physiology, The Fourth Military Medical University, Xi'an, China
| | - Zhen-Xiao Jin
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Xiao-Ming Gu
- Department of Physiology, The Fourth Military Medical University, Xi'an, China
| | - Jing-Jun Zhou
- Department of Physiology, The Fourth Military Medical University, Xi'an, China
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16
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The Emerging Role of Metabolomics in the Diagnosis and Prognosis of Cardiovascular Disease. J Am Coll Cardiol 2017; 68:2850-2870. [PMID: 28007146 DOI: 10.1016/j.jacc.2016.09.972] [Citation(s) in RCA: 224] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/09/2016] [Indexed: 12/12/2022]
Abstract
Perturbations in cardiac energy metabolism are major contributors to a number of cardiovascular pathologies. In addition, comorbidities associated with cardiovascular disease (CVD) can alter systemic and myocardial metabolism, often contributing to the worsening of cardiac function and health outcomes. State-of-the-art metabolomic technologies give us the ability to measure thousands of metabolites in biological fluids or biopsies, providing us with a metabolic fingerprint of individual patients. These metabolic profiles may serve as diagnostic and/or prognostic tools that have the potential to significantly alter the management of CVD. Herein, the authors review how metabolomics can assist in the interpretation of perturbed metabolic processes, and how this has improved our ability to understand the pathology of ischemic heart disease, atherosclerosis, and heart failure. Taken together, the integration of metabolomics with other "omics" platforms will allow us to gain insight into pathophysiological interactions of metabolites, proteins, genes, and disease states, while advancing personalized medicine.
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Abstract
The heart is a biological pump that converts chemical to mechanical energy. This process of energy conversion is highly regulated to the extent that energy substrate metabolism matches energy use for contraction on a beat-to-beat basis. The biochemistry of cardiac metabolism includes the biochemistry of energy transfer, metabolic regulation, and transcriptional, translational as well as posttranslational control of enzymatic activities. Pathways of energy substrate metabolism in the heart are complex and dynamic, but all of them conform to the First Law of Thermodynamics. The perspectives expand on the overall idea that cardiac metabolism is inextricably linked to both physiology and molecular biology of the heart. The article ends with an outlook on emerging concepts of cardiac metabolism based on new molecular models and new analytical tools. © 2016 American Physiological Society. Compr Physiol 6:1675-1699, 2016.
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Affiliation(s)
- Heinrich Taegtmeyer
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston
| | - Truong Lam
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston
| | - Giovanni Davogustto
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston
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18
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1 H NMR-derived metabolomics of filtered serum of myocardial ischemia in unstable angina patients. Clin Chim Acta 2016; 456:56-62. [DOI: 10.1016/j.cca.2016.02.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/01/2016] [Accepted: 02/25/2016] [Indexed: 11/22/2022]
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Malik A, Sharma U, Lakshmy R, Narang R, Jagannathan NR. Biochemical characterization of blood plasma of coronary artery disease patients by in vitro high-resolution proton NMR spectroscopy. J Biosci 2015; 40:31-9. [DOI: 10.1007/s12038-014-9493-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Abstract
Heart failure is a leading cause of morbidity and mortality worldwide, currently affecting 5 million Americans. A syndrome defined on clinical terms, heart failure is the end result of events occurring in multiple heart diseases, including hypertension, myocardial infarction, genetic mutations and diabetes, and metabolic dysregulation, is a hallmark feature. Mounting evidence from clinical and preclinical studies suggests strongly that fatty acid uptake and oxidation are adversely affected, especially in end-stage heart failure. Moreover, metabolic flexibility, the heart's ability to move freely among diverse energy substrates, is impaired in heart failure. Indeed, impairment of the heart's ability to adapt to its metabolic milieu and associated metabolic derangement are important contributing factors in the heart failure pathogenesis. Elucidation of molecular mechanisms governing metabolic control in heart failure will provide critical insights into disease initiation and progression, raising the prospect of advances with clinical relevance.
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21
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Piao L, Fang YH, Parikh K, Ryan JJ, Toth PT, Archer SL. Cardiac glutaminolysis: a maladaptive cancer metabolism pathway in the right ventricle in pulmonary hypertension. J Mol Med (Berl) 2013; 91:1185-97. [PMID: 23794090 DOI: 10.1007/s00109-013-1064-7] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 05/09/2013] [Accepted: 06/06/2013] [Indexed: 11/24/2022]
Abstract
UNLABELLED The rapid growth of cancer cells is permitted by metabolic changes, notably increased aerobic glycolysis and increased glutaminolysis. Aerobic glycolysis is also evident in the hypertrophying myocytes in right ventricular hypertrophy (RVH), particularly in association with pulmonary arterial hypertension (PAH). It is unknown whether glutaminolysis occurs in the heart. We hypothesized that glutaminolysis occurs in RVH and assessed the precipitating factors, transcriptional mechanisms, and physiological consequences of this metabolic pathway. RVH was induced in two models, one with PAH (Monocrotaline-RVH) and the other without PAH (pulmonary artery banding, PAB-RVH). Despite similar RVH, ischemia as determined by reductions in RV VEGFα, coronary blood flow, and microvascular density was greater in Monocrotaline-RVH versus PAB-RVH. A sixfold increase in (14)C-glutamine metabolism occurred in Monocrotaline-RVH but not in PAB-RVH. In the RV working heart model, the glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON) decreased glutaminolysis, caused a reciprocal increase in glucose oxidation, and elevated cardiac output. Consistent with the increased glutaminolysis in RVH, RV expressions of glutamine transporters (SLC1A5 and SLC7A5) and mitochondrial malic enzyme were elevated (Monocrotaline-RVH > PAB-RVH > control). Capillary rarefaction and glutamine transporter upregulation also occurred in RVH in patients with PAH. cMyc and Max, known to mediate transcriptional upregulation of glutaminolysis, were increased in Monocrotaline-RVH. In vivo, DON (0.5 mg/kg/day × 3 weeks) restored pyruvate dehydrogenase activity, reduced RVH, and increased cardiac output (89 ± 8, vs. 55 ± 13 ml/min, p < 0.05) and treadmill distance (194 ± 71, vs. 36 ±7 m, p < 0.05) in Monocrotaline-RVH. Glutaminolysis is induced in the RV in PAH by cMyc-Max, likely as a consequence of RV ischemia. Inhibition of glutaminolysis restores glucose oxidation and has a therapeutic benefit in vivo. KEY MESSAGE Patients with pulmonary artery hypertension (PAH) have evidence of cardiac glutaminolysis. Cardiac glutaminolysis is associated with microvascular rarefaction/ischemia. As in cancer, cardiac glutaminolysis results from activation of cMyc-Max. The specific glutaminolysis inhibitor DON regresses right ventricular hypertrophy. DON improves cardiac function and exercise capacity in an animal model of PAH.
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Affiliation(s)
- Lin Piao
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, IL, USA
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22
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Chinopoulos C. Which way does the citric acid cycle turn during hypoxia? The critical role of α-ketoglutarate dehydrogenase complex. J Neurosci Res 2013; 91:1030-43. [PMID: 23378250 DOI: 10.1002/jnr.23196] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 11/19/2012] [Accepted: 11/28/2012] [Indexed: 01/15/2023]
Abstract
The citric acid cycle forms a major metabolic hub and as such it is involved in many disease states involving energetic imbalance. In spite of the fact that it is being branded as a "cycle", during hypoxia, when the electron transport chain does not oxidize reducing equivalents, segments of this metabolic pathway remain operational but exhibit opposing directionalities. This serves the purpose of harnessing high-energy phosphates through matrix substrate-level phosphorylation in the absence of oxidative phosphorylation. In this Mini-Review, these segments are appraised, pointing to the critical importance of the α-ketoglutarate dehydrogenase complex dictating their directionalities.
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Affiliation(s)
- Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary.
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Drake KJ, Sidorov VY, McGuinness OP, Wasserman DH, Wikswo JP. Amino acids as metabolic substrates during cardiac ischemia. Exp Biol Med (Maywood) 2012; 237:1369-78. [PMID: 23354395 PMCID: PMC3816490 DOI: 10.1258/ebm.2012.012025] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The heart is well known as a metabolic omnivore in that it is capable of consuming fatty acids, glucose, ketone bodies, pyruvate, lactate, amino acids and even its own constituent proteins, in order of decreasing preference. The energy from these substrates supports not only mechanical contraction, but also the various transmembrane pumps and transporters required for ionic homeostasis, electrical activity, metabolism and catabolism. Cardiac ischemia - for example, due to compromise of the coronary vasculature or end-stage heart failure - will alter both electrical and metabolic activity. While the effects of myocardial ischemia on electrical propagation and stability have been studied in depth, the effects of ischemia on metabolic substrate preference has not been fully appreciated: oxygen deprivation during ischemia will significantly alter the relative ability of the heart to utilize each of these substrates. Although changes in cardiac metabolism are understood to be an underlying component in almost all cardiac myopathies, the potential contribution of amino acids in maintaining cardiac electrical conductance and stability during ischemia is underappreciated. Despite clear evidence that amino acids exert cardioprotective effects in ischemia and other cardiac disorders, their role in the metabolism of the ischemic heart has yet to be fully elucidated. This review synthesizes the current literature of the metabolic contribution of amino acids during ischemia by analyzing relevant historical and recent research.
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Affiliation(s)
- Kenneth J. Drake
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, TN 37235
| | - Veniamin Y. Sidorov
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, TN 37235
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235
| | - Owen P. McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, TN 37235
| | - David H. Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - John P. Wikswo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, TN 37235
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235
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Karlstädt A, Fliegner D, Kararigas G, Ruderisch HS, Regitz-Zagrosek V, Holzhütter HG. CardioNet: a human metabolic network suited for the study of cardiomyocyte metabolism. BMC SYSTEMS BIOLOGY 2012; 6:114. [PMID: 22929619 PMCID: PMC3568067 DOI: 10.1186/1752-0509-6-114] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Accepted: 08/16/2012] [Indexed: 02/08/2023]
Abstract
Background Availability of oxygen and nutrients in the coronary circulation is a crucial determinant of cardiac performance. Nutrient composition of coronary blood may significantly vary in specific physiological and pathological conditions, for example, administration of special diets, long-term starvation, physical exercise or diabetes. Quantitative analysis of cardiac metabolism from a systems biology perspective may help to a better understanding of the relationship between nutrient supply and efficiency of metabolic processes required for an adequate cardiac output. Results Here we present CardioNet, the first large-scale reconstruction of the metabolic network of the human cardiomyocyte comprising 1793 metabolic reactions, including 560 transport processes in six compartments. We use flux-balance analysis to demonstrate the capability of the network to accomplish a set of 368 metabolic functions required for maintaining the structural and functional integrity of the cell. Taking the maintenance of ATP, biosynthesis of ceramide, cardiolipin and further important phospholipids as examples, we analyse how a changed supply of glucose, lactate, fatty acids and ketone bodies may influence the efficiency of these essential processes. Conclusions CardioNet is a functionally validated metabolic network of the human cardiomyocyte that enables theorectical studies of cellular metabolic processes crucial for the accomplishment of an adequate cardiac output.
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Affiliation(s)
- Anja Karlstädt
- Institute of Biochemistry, Charité-Universitätsmedizin Berlin, Charitéplatz 1/Virchowweg 6, 10117 Berlin, Germany.
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HANET C, ROUSSEAU MF, VINCENT MARIEFRANCOISE, POULEUR H. Effects of nicardipine on myocardial metabolism and coronary haemodynamics: A review. Br J Clin Pharmacol 2012. [DOI: 10.1111/j.1365-2125.1986.tb00324.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Osterholt M, Sen S, Dilsizian V, Taegtmeyer H. Targeted metabolic imaging to improve the management of heart disease. JACC Cardiovasc Imaging 2012; 5:214-26. [PMID: 22340831 DOI: 10.1016/j.jcmg.2011.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/14/2011] [Accepted: 11/28/2011] [Indexed: 10/14/2022]
Abstract
Tracer techniques are powerful methods for assessing rates of biological processes in vivo. A case in point is intermediary metabolism of energy providing substrates, a central feature of every living cell. In the heart, the tight coupling between metabolism and contractile function offers an opportunity for the simultaneous assessment of cardiac performance at different levels in vivo: coronary flow, myocardial perfusion, oxygen delivery, metabolism, and contraction. Noninvasive imaging techniques used to identify the metabolic footprints of either normal or perturbed cardiac function are discussed.
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Affiliation(s)
- Moritz Osterholt
- Department of Internal Medicine/Division of Cardiology, University of Texas Medical School at Houston, Houston, Texas 77030, USA
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Strigun A, Wahrheit J, Niklas J, Heinzle E, Noor F. Doxorubicin increases oxidative metabolism in HL-1 cardiomyocytes as shown by 13C metabolic flux analysis. Toxicol Sci 2011; 125:595-606. [PMID: 22048646 DOI: 10.1093/toxsci/kfr298] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Doxorubicin (DXR), an anticancer drug, is limited in its use due to severe cardiotoxic effects. These effects are partly caused by disturbed myocardial energy metabolism. We analyzed the effects of therapeutically relevant but nontoxic DXR concentrations for their effects on metabolic fluxes, cell respiration, and intracellular ATP. (13)C isotope labeling studies using [U-(13)C(6)]glucose, [1,2-(13)C(2)]glucose, and [U-(13)C(5)]glutamine were carried out on HL-1 cardiomyocytes exposed to 0.01 and 0.02 μM DXR and compared with the untreated control. Metabolic fluxes were calculated by integrating production and uptake rates of extracellular metabolites (glucose, lactate, pyruvate, and amino acids) as well as (13)C-labeling in secreted lactate derived from the respective (13)C-labeled substrates into a metabolic network model. The investigated DXR concentrations (0.01 and 0.02 μM) had no effect on cell viability and beating of the HL-1 cardiomyocytes. Glycolytic fluxes were significantly reduced in treated cells at tested DXR concentrations. Oxidative metabolism was significantly increased (higher glucose oxidation, oxidative decarboxylation, TCA cycle rates, and respiration) suggesting a more efficient use of glucose carbon. These changes were accompanied by decrease of intracellular ATP. We conclude that DXR in nanomolar range significantly changes central carbon metabolism in HL-1 cardiomyocytes, which results in a higher coupling of glycolysis and TCA cycle. The myocytes probably try to compensate for decreased intracellular ATP, which in turn may be the result of a loss of NADH electrons via either formation of reactive oxygen species or electron shunting.
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Affiliation(s)
- Alexander Strigun
- Biochemical Engineering Institute, Saarland University, Saarbruecken, Germany
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Smith AC, Robinson AJ. A metabolic model of the mitochondrion and its use in modelling diseases of the tricarboxylic acid cycle. BMC SYSTEMS BIOLOGY 2011; 5:102. [PMID: 21714867 PMCID: PMC3152903 DOI: 10.1186/1752-0509-5-102] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 06/29/2011] [Indexed: 12/17/2022]
Abstract
Background Mitochondria are a vital component of eukaryotic cells and their dysfunction is implicated in a large number of metabolic, degenerative and age-related human diseases. The mechanism or these disorders can be difficult to elucidate due to the inherent complexity of mitochondrial metabolism. To understand how mitochondrial metabolic dysfunction contributes to these diseases, a metabolic model of a human heart mitochondrion was created. Results A new model of mitochondrial metabolism was built on the principle of metabolite availability using MitoMiner, a mitochondrial proteomics database, to evaluate the subcellular localisation of reactions that have evidence for mitochondrial localisation. Extensive curation and manual refinement was used to create a model called iAS253, containing 253 reactions, 245 metabolites and 89 transport steps across the inner mitochondrial membrane. To demonstrate the predictive abilities of the model, flux balance analysis was used to calculate metabolite fluxes under normal conditions and to simulate three metabolic disorders that affect the TCA cycle: fumarase deficiency, succinate dehydrogenase deficiency and α-ketoglutarate dehydrogenase deficiency. Conclusion The results of simulations using the new model corresponded closely with phenotypic data under normal conditions and provided insight into the complicated and unintuitive phenotypes of the three disorders, including the effect of interventions that may be of therapeutic benefit, such as low glucose diets or amino acid supplements. The model offers the ability to investigate other mitochondrial disorders and can provide the framework for the integration of experimental data in future studies.
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Affiliation(s)
- Anthony C Smith
- The Medical Research Council, Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
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Metabolic profiling using HPLC allows classification of drugs according to their mechanisms of action in HL-1 cardiomyocytes. Toxicol Appl Pharmacol 2011; 252:183-91. [DOI: 10.1016/j.taap.2011.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/31/2011] [Accepted: 02/06/2011] [Indexed: 10/18/2022]
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Nielsen TT, Støttrup NB, Løfgren B, Bøtker HE. Metabolic fingerprint of ischaemic cardioprotection: importance of the malate-aspartate shuttle. Cardiovasc Res 2011; 91:382-91. [PMID: 21349875 DOI: 10.1093/cvr/cvr051] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The convergence of cardioprotective intracellular signalling pathways to modulate mitochondrial function as an end-target of cytoprotective stimuli is well described. However, our understanding of whether the complementary changes in mitochondrial energy metabolism are secondary responses or inherent mechanisms of ischaemic cardioprotection remains incomplete. In the heart, the malate-aspartate shuttle (MAS) constitutes the primary metabolic pathway for transfer of reducing equivalents from the cytosol into the mitochondria for oxidation. The flux of MAS is tightly linked to the flux of the tricarboxylic acid cycle and the electron transport chain, partly by the amino acid l-glutamate. In addition, emerging evidence suggests the MAS is an important regulator of cytosolic and mitochondrial calcium homeostasis. In the isolated rat heart, inhibition of MAS during ischaemia and early reperfusion by the aminotransferase inhibitor aminooxyacetate induces infarct limitation, improves haemodynamic responses, and modulates glucose metabolism, analogous to effects observed in classical ischaemic preconditioning. On the basis of these findings, the mechanisms through which MAS preserves mitochondrial function and cell survival are reviewed. We conclude that the available evidence is supportive of a down-regulation of mitochondrial respiration during lethal ischaemia with a gradual 'wake-up' during reperfusion as a pivotal feature of ischaemic cardioprotection. Finally, comments on modulating myocardial energy metabolism by the cardioprotective amino acids glutamate and glutamine are given.
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Affiliation(s)
- Torsten Toftegaard Nielsen
- Department of Cardiology, Skejby Hospital, Aarhus University Hospital, Brendstrupgaardsvej 100, Aarhus N, Denmark.
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Løfgren B, Povlsen JA, Rasmussen LE, Støttrup NB, Solskov L, Krarup PM, Kristiansen SB, Bøtker HE, Nielsen TT. Amino acid transamination is crucial for ischaemic cardioprotection in normal and preconditioned isolated rat hearts--focus on L-glutamate. Exp Physiol 2009; 95:140-52. [PMID: 19717487 DOI: 10.1113/expphysiol.2009.049452] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have found that cardioprotection by l-glutamate mimics protection by classical ischaemic preconditioning (IPC). We investigated whether the effect of IPC involves amino acid transamination and whether IPC modulates myocardial glutamate metabolism. In a glucose-perfused, isolated rat heart model subjected to 40 min global no-flow ischaemia and 120 min reperfusion, the effects of IPC (2 cycles of 5 min ischaemia and 5 min reperfusion) and continuous glutamate (20 mm) administration during reperfusion on infarct size and haemodynamic recovery were studied. The effect of inhibiting amino acid transamination was evaluated by adding the amino acid transaminase inhibitor amino-oxyacetate (AOA; 0.025 mm) during reperfusion. Changes in coronary effluent, interstitial (microdialysis) and intracellular glutamate ([GLUT](i)) concentrations were measured. Ischaemic preconditioning and postischaemic glutamate administration reduced infarct size to the same extent (41 and 40%, respectively; P < 0.05 for both), without showing an additive effect. Amino-oxyacetate abolished infarct reduction by IPC and glutamate, and increased infarct size in both control and IPC hearts in a dose-dependent manner. Ischaemic preconditioning increased [GLUT](i) before ischaemia (P < 0.01) and decreased the release of glutamate during the first 10 min of reperfusion (P = 0.03). A twofold reduction in [GLUT](i) from the preischaemic state to 45 min of reperfusion (P = 0.0001) suggested increased postischaemic glutamate utilization in IPC hearts. While IPC and AOA changed haemodynamics in accordance with infarct size, glutamate decreased haemodynamic recovery despite reduced infarct size. In conclusion, ischaemic cardioprotection of the normal and IPC-protected heart depends on amino acid transamination and activity of the malate-aspartate shuttle during reperfusion. Underlying mechanisms of IPC include myocardial glutamate metabolism.
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Affiliation(s)
- Bo Løfgren
- Department of Cardiology B, Arhus University Hospital, Skejby, 8200 Arhus N, Denmark
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Abstract
Cardioplegic solutions rich in the hydrophilic, basic amino acids, glutamate and aspartate, have enhanced myocardial preservation and left ventricular function. This has been demonstrated in assorted animal preparations involving ischemia with and without reperfusion. Published clinical data, though limited, strongly support the contention that these amino acids have myocardial protective properties. Several biochemical mechanisms exist by which certain amino acids may attenuate ischemic or reperfusion injury. Glutamate and aspartate may become preferred myocardial fuels in the setting of ischemia. They may also reduce myocardial ammonia production and reduce cytoplasmic lactate levels, thereby deinhibiting glycolysis. Some amino acids may become substrate for the citric acid cycle. Glutamate and aspartate also move reducing equivalents from cytoplasm to mitochondria where they are necessary for oxidative phosphorylation and energy generation. A rationale exists for the use of an amino acid-rich cardioplegia-like solution in myocardial infarction. These solutions are safe and inexpensive.
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Affiliation(s)
- M Arsenian
- Department of Medicine, Addison-Gilbert Hospital, Gloucester, Massachusetts, USA
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Lewis GD, Wei R, Liu E, Yang E, Shi X, Martinovic M, Farrell L, Asnani A, Cyrille M, Ramanathan A, Shaham O, Berriz G, Lowry PA, Palacios IF, Taşan M, Roth FP, Min J, Baumgartner C, Keshishian H, Addona T, Mootha VK, Rosenzweig A, Carr SA, Fifer MA, Sabatine MS, Gerszten RE. Metabolite profiling of blood from individuals undergoing planned myocardial infarction reveals early markers of myocardial injury. J Clin Invest 2008; 118:3503-12. [PMID: 18769631 DOI: 10.1172/jci35111] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 07/09/2008] [Indexed: 11/17/2022] Open
Abstract
Emerging metabolomic tools have created the opportunity to establish metabolic signatures of myocardial injury. We applied a mass spectrometry-based metabolite profiling platform to 36 patients undergoing alcohol septal ablation treatment for hypertrophic obstructive cardiomyopathy, a human model of planned myocardial infarction (PMI). Serial blood samples were obtained before and at various intervals after PMI, with patients undergoing elective diagnostic coronary angiography and patients with spontaneous myocardial infarction (SMI) serving as negative and positive controls, respectively. We identified changes in circulating levels of metabolites participating in pyrimidine metabolism, the tricarboxylic acid cycle and its upstream contributors, and the pentose phosphate pathway. Alterations in levels of multiple metabolites were detected as early as 10 minutes after PMI in an initial derivation group and were validated in a second, independent group of PMI patients. A PMI-derived metabolic signature consisting of aconitic acid, hypoxanthine, trimethylamine N-oxide, and threonine differentiated patients with SMI from those undergoing diagnostic coronary angiography with high accuracy, and coronary sinus sampling distinguished cardiac-derived from peripheral metabolic changes. Our results identify a role for metabolic profiling in the early detection of myocardial injury and suggest that similar approaches may be used for detection or prediction of other disease states.
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Affiliation(s)
- Gregory D Lewis
- Cardiology Division and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
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Kristiansen SB, Lfgren B, Stttrup NB, Kimose HH, Nielsen-Kudsk JE, Btker HE, Nielsen TT. CARDIOPROTECTION BY l-GLUTAMATE DURING POSTISCHAEMIC REPERFUSION: REDUCED INFARCT SIZE AND ENHANCED GLYCOGEN RESYNTHESIS IN A RAT INSULIN-FREE HEART MODEL. Clin Exp Pharmacol Physiol 2008; 35:884-8. [DOI: 10.1111/j.1440-1681.2008.04914.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Vánky FB, Håkanson E, Jorfeldt L, Svedjeholm R. Does glutamate influence myocardial and peripheral tissue metabolism after aortic valve replacement for aortic stenosis? Clin Nutr 2006; 25:913-22. [PMID: 16737761 DOI: 10.1016/j.clnu.2006.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Revised: 03/01/2006] [Accepted: 04/03/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND & AIMS Glutamate plays an important role for myocardial metabolism in association with ischaemia. Patients with coronary artery disease characteristically demonstrate increased uptake of glutamate. Improved recovery of myocardial metabolism and haemodynamic state after coronary surgery has been reported in patients treated with glutamate infusion. However, the effect of glutamate has not been studied after other cardiac surgical procedures. In addition, the effects of glutamate on peripheral tissue metabolism remain to be described. METHODS Twenty patients undergoing surgery for aortic stenosis were studied after randomisation to blinded infusion of glutamate or saline during 1h immediately after skin closure. Myocardial and leg tissue metabolism were assessed with organ balance techniques. RESULTS Postoperative glutamate infusion induced a marked increase in myocardial and leg tissue uptake of glutamate. This was associated with a significant uptake of lactate in the heart. The negative arterial-venous differences of amino acids and free fatty acids across the leg were significantly smaller in the glutamate group. Haemodynamic state remained stable and did not differ between groups. CONCLUSION The heart and peripheral tissues consumed the exogenously administered glutamate after surgery for aortic stenosis. Potentially favourable effects of glutamate on myocardial and peripheral tissue metabolism are suggested.
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Affiliation(s)
- Farkas B Vánky
- Department of Cardiothoracic Surgery, Linköping Heart Centre, University Hospital, SE-581 85 Linköping, Sweden
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Amark K, Berggren H, Björk K, Ekroth A, Ekroth R, Nilsson K, Sunnegårdh J. Myocardial Metabolism is Better Preserved After Blood Cardioplegia in Infants. Ann Thorac Surg 2006; 82:172-8. [PMID: 16798209 DOI: 10.1016/j.athoracsur.2006.01.093] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Revised: 01/22/2006] [Accepted: 01/26/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND We have previously reported improved hemodynamic function after blood cardioplegia in comparison with crystalloid cardioplegia. Furthermore, lactate was released from the heart after crystalloid cardioplegia but not after blood cardioplegia. The purpose of this study was to determine whether the difference in substrate metabolism between the two cardioplegia methods was restricted to lactate, or whether the difference in metabolic derangement was more extensive. METHODS Thirty consecutive infants with complete atrioventricular septal defects were included in this prospective, randomized, controlled study. Arterial and coronary sinus blood concentrations of substrates and amino acids were measured after weaning from bypass. RESULTS After crystalloid cardioplegia, there was a myocardial uptake of glutamate (p = 0.003), leucine (p = 0.03), lysine (p = 0.003), and beta-hydroxybutyrate (p = 0.004), whereas lactate was released (p = 0.03). After blood cardioplegia, there was a myocardial uptake of free fatty acids (p = 0.01) but no uptake of amino acids and no release of lactate. CONCLUSIONS There are differences in myocardial substrate metabolism between blood cardioplegia and crystalloid cardioplegia, which involve carbohydrates and amino acids. The differences may include lipids but our data in this respect are not conclusive.
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Affiliation(s)
- Kerstin Amark
- Department of Pediatrics, The Queen Silvia Children's Hospital, Göteborg, Sweden.
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Stanley WC, Recchia FA, Lopaschuk GD. Myocardial substrate metabolism in the normal and failing heart. Physiol Rev 2005; 85:1093-129. [PMID: 15987803 DOI: 10.1152/physrev.00006.2004] [Citation(s) in RCA: 1406] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The alterations in myocardial energy substrate metabolism that occur in heart failure, and the causes and consequences of these abnormalities, are poorly understood. There is evidence to suggest that impaired substrate metabolism contributes to contractile dysfunction and to the progressive left ventricular remodeling that are characteristic of the heart failure state. The general concept that has recently emerged is that myocardial substrate selection is relatively normal during the early stages of heart failure; however, in the advanced stages there is a downregulation in fatty acid oxidation, increased glycolysis and glucose oxidation, reduced respiratory chain activity, and an impaired reserve for mitochondrial oxidative flux. This review discusses 1) the metabolic changes that occur in chronic heart failure, with emphasis on the mechanisms that regulate the changes in the expression of metabolic genes and the function of metabolic pathways; 2) the consequences of these metabolic changes on cardiac function; 3) the role of changes in myocardial substrate metabolism on ventricular remodeling and disease progression; and 4) the therapeutic potential of acute and long-term manipulation of cardiac substrate metabolism in heart failure.
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Affiliation(s)
- William C Stanley
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106-4970, USA.
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Abstract
The pathophysiology of myocardial hibernation is characterized as a situation of reduced regional contractile function distal to a coronary artery stenosis that recovers after removal of the coronary stenosis. A subacute "downregulation" of contractile function in response to reduced regional myocardial blood flow exists, which normalizes regional energy and substrate metabolism but does not persist for more than 12-24 h. Chronic hibernation develops in response to one or more episodes of myocardial ischemia-reperfusion, possibly progressing from repetitive stunning with normal blood flow to hibernation with reduced blood flow. An upregulation of a protective gene program is seen in hibernating myocardium, putting it into the context of preconditioning. The morphology of hibernating myocardium is characterized by both adaptive and degenerative features.
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Affiliation(s)
- Gerd Heusch
- Institut für Pathophysiologie, Zentrum für Innere Medizin, Universitätsklinikum Essen, Hufelandstr. 55, 45122 Essen, Germany.
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Abstract
Amino acids are essential for body protein synthesis. Moreover, they can be used to produce energy within the cells. For protein turnover, normal plasma amino acid concentration enhances proteolytic suppression by insulin; furthermore, hyperaminoacidemia can stimulate protein synthesis both in the presence of baseline insulin and in hyperinsulinemic subjects with type 1 diabetes. In humans, the availability of amino acids represents a factor more important than insulin in maintaining protein synthesis in skeletal muscle. Among amino acids, branched-chain amino acids exert an anabolic effect on heart protein metabolism, and their uptake by the myocardium is increased by increasing their circulating concentrations. An important aspect of branched-chain amino acid metabolism in the heart (mainly in the ischemic heart) is that branch-chain amino acid infusion can diminish myocardial lactate; in this way, the inhibition of anaerobic energy phosphate caused by accumulation of lactate can be overridden. Plasma amino acid availability plays an important role in promoting protein synthesis and in energy production, both in peripheral skeletal muscle and in the myocardium.
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Affiliation(s)
- Roberto Aquilani
- Service of Metabolic and Nutritional Pathophysiology, Salvatore Maugeri Foundation, IRCCS, Medical Center of Montescano, Pavia, Italy.
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Bortone F, Mazzoni M, Repossini A, Campolo J, Ceriani R, Devoto E, Parolini M, De Maria R, Arena V, Parodi O. Myocardial lactate metabolism in relation to preoperative regional wall motion and to early functional recovery after coronary revascularization. J Cardiothorac Vasc Anesth 2003; 17:478-85. [PMID: 12968236 DOI: 10.1016/s1053-0770(03)00153-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To evaluate myocardial lactate metabolism as a marker of functional status after surgical coronary revascularization. DESIGN Single-center, prospective, cohort study. SETTING Tertiary care teaching hospital. PARTICIPANTS Fifty patients with stable angina, ejection fraction >0.40, undergoing coronary artery bypass surgery for multiple-vessel disease. MEASUREMENTS AND MAIN RESULTS Before (T1) and 30 minutes (T2) after coronary artery bypass grafting, the authors simultaneously sampled blood from artery and coronary sinus to determine myocardial lactate dynamics and performed transesophageal echocardiography (TEE) to assess segmental wall motion. Wall motion score index (WMSI) was calculated with an online/offline comparison. At T2, WMSI improved from 1.40 +/- 0.31 to 1.17 +/- 0.23 (p = 0.0001). Preoperatively, 2 patterns of lactate balance were found: 39 patients were lactate extractors (17% +/- 10%) and 11 were lactate producers (-11% +/- 11%). At T2, lactate metabolism was shifted towards a pattern opposite to the baseline: delta lactate extraction was -8% +/- 16% in extractors at T1 versus 7% +/- 9% in producers at T1 (p = 0.003). Changes in WMSI were not correlated with changes in lactate utilization. No single preoperative variable predicted postoperative WMSI or its changes from baseline. Cardiopulmonary bypass (CPB) time was the only significant predictor of postoperative lactate extraction by multivariate regression (r = -0.46, p = 0.001): at T2, patients in the highest CPB time quartile showed frank lactate production (-6% +/- 13%) when compared with those in the lowest quartile (15% +/- 11%, p = 0.005). However, postoperative WMSI was similar in different CPB time groups. CONCLUSIONS Myocardial lactate metabolism pattern is not associated with functional status before and early after successful coronary revascularization. CPB time was the only significant predictor of postoperative lactate extraction. Measurement of lactate does not appear to be a valuable tool to assess the coupling of myocardial regional function and metabolism in the setting of coronary artery surgery and mild-to-moderate functional impairment.
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Affiliation(s)
- Franco Bortone
- Department of Anesthesia and Cardiac Surgery, Humanitas Gavazzeni, Bergamo, Italy
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Us MH, Ozkan S, Oğuş T, Acar HV, Ege T, Cakir O, Gökben M, Oztürk OY. Efficacy of topically applied glutamate-aspartate and pentoxifylline solutions in decreasing myocardial damage during open-heart surgery in rats. J Int Med Res 2001; 29:497-502. [PMID: 11803733 DOI: 10.1177/147323000102900605] [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: 11/15/2022] Open
Abstract
During open-heart surgery, the period between cross-clamping and maintenance of homogeneous diastolic arrest is often accompanied by significant ischaemic-hypoxic injury. The topical application of glutamate-aspartate or pentoxifylline may reduce energy demands during this period and thus prevent myocardial damage. Fifty rats were divided into five groups. In group A (control) the pericardial cavity was opened, all inlet and outlet vasculature cross-clamped, and the heart excised after 60 s. In groups B-E, the pericardial cavity was opened, all inlet and outlet vasculature cross-clamped for 60 s (groups B and D) or 90 s (groups C and E), and the pericardial cavity filled with glutamate-aspartate solution (groups B and C) or pentoxifylline solution (groups D and E) for 2 min. Following clamping, blood was withdrawn from the right atrium for biochemical analysis, and the heart excised for histological analysis. Histopathological and biochemical analysis showed a significant reduction in ischaemic-hypoxic cardiac injury in rats treated with topically applied glutamate-aspartate or pentoxifylline.
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Affiliation(s)
- M H Us
- Department of Cardiovascular Surgery, GATA Haydarpaşa Training Hospital, Istanbul, Turkey
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Caputo M, Bryan AJ, Calafiore AM, Suleiman MS, Angelini GD. Intermittent antegrade hyperkalaemic warm blood cardioplegia supplemented with magnesium prevents myocardial substrate derangement in patients undergoing coronary artery bypass surgery. Eur J Cardiothorac Surg 1998; 14:596-601. [PMID: 9879871 DOI: 10.1016/s1010-7940(98)00247-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE The influence of the addition of magnesium on myocardial protection with intermittent antegrade warm blood hyperkalaemic cardioplegia in patients undergoing coronary artery surgery was investigated and compared with intermittent antegrade warm blood hyperkalaemic cardioplegia only. METHODS Twenty-three patients undergoing primary elective coronary revascularization were randomized to one of two different techniques of myocardial protection. In the first group, myocardial protection was induced using intermittent antegrade warm blood hyperkalaemic cardioplegia. In the second group, the same technique was used except that magnesium was added to the cardioplegia. Intracellular substrates (ATP, lactate and amino acids) were measured in left ventricular biopsies collected 5 min after institution of cardiopulmonary bypass, after 30 min of ischaemic arrest and 20 min after reperfusion. RESULTS There were no significant changes in the intracellular concentration of ATP or free amino acid pool in biopsies taken at the end of the period of myocardial ischaemia. However, the addition of magnesium prevented the significant increase in the intracellular concentration of lactate seen with intermittent antegrade warm blood hyperkalaemic cardioplegia. Upon reperfusion there was a significant fall in ATP and amino acid concentration when the technique of intermittent antegrade warm blood hyperkalaemic cardioplegia was used but not when magnesium was added to the cardioplegia. CONCLUSIONS This work shows that intermittent antegrade warm blood hyperkalaemic cardioplegia supplemented with magnesium prevents substrate derangement early after reperfusion.
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Affiliation(s)
- M Caputo
- Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, UK
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Abstract
Decreased myocardial contraction occurs as a consequence of a reduction in blood flow. The concept of hibernation implies a downregulation of contractile function as an adaptation to a reduction in myocardial blood flow that serves to maintain myocardial integrity and viability during persistent ischemia. Unequivocal evidence for this concept exists in scenarios of myocardial ischemia that lasts for several hours, and sustained perfusion-contraction matching, recovery of energy and substrate metabolism, the potential for recruitment of inotropic reserve at the expense of metabolic recovery, and lack of necrosis are established criteria of short-term hibernation. The mechanisms of short-term hibernation, apart from reduced calcium responsiveness, are not clear at present. Experimental studies with chronic coronary stenosis lasting more than several hours have failed to continuously monitor flow and function. Nevertheless, a number of studies in chronic animal models and patients have demonstrated regional myocardial dysfunction at reduced resting blood flow that recovered upon reperfusion, consistent with chronic hibernation. Further studies are required to distinguish chronic hibernation from cumulative stunning. With a better understanding of the mechanisms underlying short-term hibernation, it is hoped that these adaptive responses can be recruited and reinforced to minimize the consequences of acute myocardial ischemia and delay impending infarction. Patients with chronic hibernation must be identified and undergo adequate reperfusion therapy.
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Affiliation(s)
- G Heusch
- Department of Pathophysiology, Centre of Internal Medicine, University of Essen, School of Medicine, Germany
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Vanhanen I, Håkanson E, Jorfeldt L, Svedjeholm R. Intravenous aspartate infusion after a coronary operation: effects on myocardial metabolism and hemodynamic state. Ann Thorac Surg 1998; 65:1296-302. [PMID: 9594855 DOI: 10.1016/s0003-4975(98)00155-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND In a previous study glutamate infusion after coronary artery bypass grafting was associated with beneficial effects on myocardial metabolism and myocardial performance. It has been claimed that aspartate is more important than glutamate for the recovery of myocardial metabolism after cardioplegic arrest. Therefore, the metabolic and hemodynamic effects of aspartate were studied after coronary artery bypass grafting. METHODS Fifty to 240 mL of a 0.1 mol/L aspartic acid solution was infused intravenously during 60 minutes in 10 patients early after coronary artery bypass grafting. Myocardial metabolism was studied using the coronary sinus catheter technique. RESULTS Aspartate infusion caused a significant increase in the arterial levels of both aspartate and glutamate. This was associated with a significant increase in myocardial uptake of aspartate and a decrease in myocardial uptake of glutamate. Myocardial exchange of other substrates remained unaffected. There were no changes in hemodynamic state except an increase of heart rate and pulmonary vascular resistance. CONCLUSIONS Interactions with glutamate metabolism, compatible with competitive inhibition of myocardial glutamate uptake, which may have outweighed potential effects of aspartate, were observed. Recognition of these amino acid interactions is important as they are used together as additives in cardioplegic solutions.
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Affiliation(s)
- I Vanhanen
- Department of Cardiothoracic Surgery, Linköping Heart Center, University Hospital, Sweden
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47
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Schulz R, Kappeler C, Coenen H, Bockisch A, Heusch G. Positron emission tomography analysis of [1-(11)C] acetate kinetics in short-term hibernating myocardium. Circulation 1998; 97:1009-16. [PMID: 9529270 DOI: 10.1161/01.cir.97.10.1009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Modeling of the time-[1-(11)C]acetate activity curve assumes a constant concentration of labeled tricarboxylic acid cycle intermediates and associated metabolites, such as glutamate and aspartate, which may, however, decrease in short-term hibernating myocardium. METHODS AND RESULTS In 12 anesthetized pigs, [1-(11)C]acetate was injected as a bolus into the cannulated left anterior descending coronary artery during normoperfusion, inotropic stimulation, and early (5 to 45 minutes) and prolonged ischemia (60 to 90 minutes). Regional myocardial oxygen consumption (MVO2, microliters per minute per gram) was measured, and the absence of necrosis was verified by triphenyl tetrazolium chloride staining. Inotropic stimulation increased MVO2 from 52.5+/-7.4 to 195.4+/-36.2 (mean+/-SD) and the rate constant (kmono, minutes[-1]) of [1-(11)C]acetate clearance from 0.094+/-0.018 to 0.322+/-0.076. During early ischemia, MVO2 and kmono were decreased to 24.3+/-8.5 and 0.061+/-0.011, respectively. Kmono closely correlated to MVO2 during normoperfusion, inotropic stimulation, and early ischemia. In short-term hibernating myocardium, however, at an unchanged MVO2, kmono increased toward control values (0.080+/-0.014). Myocardial glutamate and aspartate concentrations (biopsies) decreased to 47+/-26% and 77+/-18%; the peak count rate decreased to 66+/-22% of its respective control value. After correction for the decreases in glutamate and aspartate or in peak count rate, kmono was again decreased (0.050+/-0.016 or 0.052+/-0.014, respectively), and a close relationship to MVO2 was restored. CONCLUSIONS Kmono correlates to MVO2 in short-term hibernating myocardium when the decreases in aspartate and glutamate or in peak count rate are considered.
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Affiliation(s)
- R Schulz
- Department of Pathophysiology, Center of Internal Medicine, University Essen, School of Medicine, FRG
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Ghomeshi HR, Tian G, Ye J, Sun J, Hoffenberg EF, Salerno TA, Deslauriers R. Aspartate/glutamate-enriched blood does not improve myocardial energy metabolism during ischemia-reperfusion: a 31P magnetic resonance spectroscopic study in isolated pig hearts. J Thorac Cardiovasc Surg 1997; 113:1068-77; discussion 1077-80. [PMID: 9202688 DOI: 10.1016/s0022-5223(97)70294-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Our objective was to test the effects of exogenous L-aspartate and L-glutamate on myocardial energy metabolism during ischemia-reperfusion. METHODS Phosphorus 31-magnetic resonance spectroscopy was used to observe cellular energetics and intracellular pH in isolated pig hearts perfused with blood (group A, n = 8) or blood enriched with 13 mmol/L each of L-aspartate and L-glutamate (group B, n = 6). The hearts were subjected to 30 minutes of total normothermic ischemia and then reperfused for 40 minutes. Two hearts from each group were inotropically stimulated by titration with calcium after normokalemic reperfusion. Left ventricular function was measured with the use of a compliant balloon and oxygen consumption was calculated. RESULTS Magnetic resonance spectroscopy showed no decrease in the rate of energy decline during ischemia for group B versus group A. No significant differences were observed between the two groups in terms of myocardial function, oxygen consumption, or the rate or extent of high-energy phosphate recovery after normokalemic reperfusion or inotropic stimulation. Inotropic stimulation of postischemic hearts, however, led to dramatic improvement in myocardial function in both groups (p < 0.05 for all parameters) and significant improvement in oxygen consumption (p = 0.01). CONCLUSIONS In a normal, isolated, blood-perfused pig heart subjected to 30 minutes of total normothermic ischemia, (1) enrichment of the perfusate with aspartate/glutamate before and after ischemia affects neither myocardial energy metabolism during ischemia-reperfusion nor postischemic recovery of myocardial function or oxygen consumption and (2) inotropic stimulation can recruit significant postischemic function and sufficient aerobic respiration to support it, irrespective of aspartate/glutamate enrichment.
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Affiliation(s)
- H R Ghomeshi
- Institute for Biodiagnostic, National Research Council of Canada, Winnipeg, Manitoba, Canada
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Yabe T, Mitsunami K, Inubushi T, Kinoshita M. Quantitative measurements of cardiac phosphorus metabolites in coronary artery disease by 31P magnetic resonance spectroscopy. Circulation 1995; 92:15-23. [PMID: 7788910 DOI: 10.1161/01.cir.92.1.15] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND 31P metabolite measurements in the human heart by magnetic resonance spectroscopy (MRS) have been reported previously. By use of a method in which metabolite content was quantified with reference to a standard located outside the chest, it has become possible to measure the content of phosphocreatine (PCr) and ATP in vivo in the human heart. In this study, PCr and ATP contents were measured by 31P MRS and compared in human myocardium with reversible ischemia or scar diagnosed by exercise thallium scintigraphy. METHODS AND RESULTS Forty-one subjects with stenosis of the left anterior descending coronary artery (> 50%) and 11 healthy control subjects (C) composed the present study group. Patients were divided into two groups on the basis of exercise 201Tl scintigraphy: a reversible 201Tl defect group (RD[+], n = 29) who demonstrated redistribution at late image and a fixed 201Tl defect group (RD[-], n = 12). While the subjects lay supine within the magnet, 31P MR spectra were obtained from the anterior and apical regions of the left ventricle by slice-selected one-dimensional chemical shift imaging. For metabolite quantification, a standard was placed at the center of the surface coil. ANOVA revealed significant differences among the three groups with respect to the mean (+/- SD) PCr at rest (C, 12.14 +/- 4.25 > RD[+], 7.64 +/- 3.00 > RD[-], 3.94 +/- 2.21 mumol/g wet heart tissue, P < .05) as well as a significant decrease in ATP in the RD(-) group (C, 7.72 +/- 2.97; RD[+], 6.35 +/- 3.17 > RD[-], 4.35 +/- 1.52 mumol/g wet heart tissue, P < .05). CONCLUSIONS Compared with healthy control subjects, PCr content decreased significantly in patients with both reversible and fixed 201Tl defects, and ATP content decreased significantly in subjects with fixed thallium defects. These results suggest that the measurement of ATP content in the human heart by 31P MRS is a clinically important method for the evaluation of myocardial viability.
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Affiliation(s)
- T Yabe
- First Department of Internal Medicine, Shiga University of Medical Science, Otsu, Japan
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50
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Wiese S, Askanazi J, Manner T, Katz DP, Buttrick P. Effect of substrate manipulation on reducing ischemia/reperfusion injury in isolated perfused rat hearts. Clin Nutr 1995; 14:123-8. [PMID: 16843910 DOI: 10.1016/s0261-5614(95)80032-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/1994] [Accepted: 10/31/1994] [Indexed: 11/25/2022]
Abstract
The objective of this investigation was to assess the effect of substrate manipulation on reducing ischemia/reperfusion injury (IRI). Isolated rat hearts were perfused with modified Krebs-Henseleit buffer containing either (in mM): glucose 11 (G1), glucose 22 (G2), or glucose 11 with either xylitol 11 (GX), mannitol 11 (GM), L-leucine 1 (GL), or L-glutamic acid 2 (GGA), respectively. Hearts were subjected to 10 min of global no-flow ischemia, followed by 20 min of reperfusion. Mean tissue perfusion, oxygen consumption, and peak left ventricular pressure (PLVP) were determined at baseline, in the first minute of regular heart rhythm following ischemia, and after 20 minutes of reperfusion. Reperfusion arrhythmia (in sec) was significantly (all p < 0.05) shorter in GGA (115 +/- 33) vs G1 (315 +/- 29) and G2 (273 +/- 33), and also in GL (161 +/- 26) vs G1. Dry/wet heart weight ratios were also greater in GGA (0.20), when compared with G2 (0.16), GX (0.17), GM (0.17), GM (0.17), and GL (0.17) (all p < 0.02), suggesting less cellular/interstitial edema. Percent recovery in PLVP was improved (p < 0.03) in GL (81 +/- 2) and GGA (81 +/- 2) vs. G2 (71 +/- 3), without significant alterations in oxygen consumption. Thus, cardiac IRI can be diminished by substrate manipulation, especially by augmentation of glutamate and leucine, most likely due to an improved anaerobic energy generation and utilization.
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Affiliation(s)
- S Wiese
- Department of Anesthesiology, Montefiore Medical Center, Bronx, New York, USA
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