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Harms HJ, Clemmensen T, Rosengren S, Tolbod L, Pilebro B, Wikström G, Granstam SO, Kero T, Di Carli M, Poulsen SH, Sorensen J. Association of Right Ventricular Myocardial Blood Flow With Pulmonary Pressures and Outcome in Cardiac Amyloidosis. JACC Cardiovasc Imaging 2023; 16:1193-1204. [PMID: 37052560 DOI: 10.1016/j.jcmg.2023.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/30/2022] [Accepted: 01/26/2023] [Indexed: 04/14/2023]
Abstract
BACKGROUND Cardiac amyloidosis (CA) is a restrictive and infiltrative cardiomyopathy, characterized by increased biventricular filling pressures and low output. Symptoms are predominantly of right heart origin. The role of right ventricular (RV) myocardial blood flow (MBF) in CA has not been studied. OBJECTIVES This study aimed to first associate RV MBF measured by using positron emission tomography (PET) with reference standards of RV pressures and then to explore its prognostic value in CA. METHODS Cardiac PET was performed at rest in 52 patients with CA and 9 healthy control subjects. MBF was quantified from the right and left ventricles by using 11C-acetate, 15O-water, or both (n = 25). RV pressure was measured invasively or by echocardiography. Associations between biventricular MBF toward symptoms, RV function, and outcome (death or acute heart failure) were studied in patients with CA. RESULTS MBF of the right ventricle (MBFRV) and the ratio of MBFRV and MBF of the left ventricle (MBFRV/LV) for the 2 tracers were significantly correlated (r > 0.92). MBFRV was directly correlated with RV systolic pressures with both tracers (P ≤ 0.005). MBFLV was inversely correlated with wall thickness (P < 0.0001). MBFRV/LV was significantly associated with N-terminal pro-B-type natriuretic peptide levels, NYHA functional class, RV pressures, and RV systolic function (all; P < 0.001). Twenty-six cardiac events (25 deaths) occurred during follow-up (median 44 months). MBFRV/LV higher than 56% was associated with a diagnosis of pulmonary hypertension (AUC: 0.96 [95% CI: 0.91-1.00]; P < 0.0001); and predicted outcome with HR: 9.0 (95% CI: 4.2-14.5), P < 0.0001). CONCLUSIONS Measurements of MBFRV using PET are feasible, as confirmed with 2 different tracers. Imbalance between RV and LV myocardial perfusion is associated with increased RV load and adverse events in cardiac amyloidosis.
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Affiliation(s)
- Hendrik J Harms
- Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden; Clinical Institute, Aarhus University, Aarhus, Denmark
| | | | - Sara Rosengren
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Lars Tolbod
- Clinical Institute, Aarhus University, Aarhus, Denmark
| | - Björn Pilebro
- Department of Cardiology, Umeå University, Umeå, Sweden
| | - Gerhard Wikström
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Tanja Kero
- Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden
| | | | | | - Jens Sorensen
- Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden; Clinical Institute, Aarhus University, Aarhus, Denmark.
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Sörensen J, Nordström J, Baron T, Mörner S, Granstam SO, Lubberink M, Tolbod L, van den Berg J, Flachskampf FA, Kero T, Magnusson P, Harms HJ. Diagnosis of left ventricular hypertrophy using non-ECG-gated 15O-water PET. J Nucl Cardiol 2022; 29:2361-2373. [PMID: 34286452 PMCID: PMC9553817 DOI: 10.1007/s12350-021-02734-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 06/17/2021] [Indexed: 11/30/2022]
Abstract
AIM To develop a method for diagnosing left ventricular (LV) hypertrophy from cardiac perfusion 15O-water positron emission tomography (PET). METHODS We retrospectively pooled data from 139 subjects in four research cohorts. LV remodeling patterns ranged from normal to severe eccentric and concentric hypertrophy. 15O-water PET scans (n = 197) were performed with three different PET devices. A low-end scanner (66 scans) was used for method development, and remaining scans with newer devices for a blinded evaluation. Dynamic data were converted into parametric images of perfusable tissue fraction for semi-automatic delineation of the LV wall and calculation of LV mass (LVM) and septal wall thickness (WT). LVM and WT from PET were compared to cardiac magnetic resonance (CMR, n = 47) and WT to 2D-echocardiography (2DE, n = 36). PET accuracy was tested using linear regression, Bland-Altman plots, and ROC curves. Observer reproducibility were evaluated using intraclass correlation coefficients. RESULTS High correlations were found in the blinded analyses (r ≥ 0.87, P < 0.0001 for all). AUC for detecting increased LVM and WT (> 12 mm and > 15 mm) was ≥ 0.95 (P < 0.0001 for all). Reproducibility was excellent (ICC ≥ 0.93, P < 0.0001). CONCLUSION 15O-water PET might detect LV hypertrophy with high accuracy and precision.
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Affiliation(s)
- Jens Sörensen
- Department of Surgical Sciences, Radiology & Nuclear Medicine, Uppsala University, Uppsala, Sweden.
- PET Center, Entrance 86, Uppsala University Hospital, 751 85, Uppsala, Sweden.
| | - Jonny Nordström
- Department of Surgical Sciences, Radiology & Nuclear Medicine, Uppsala University, Uppsala, Sweden
- Centre for Research and Development, Region Gävleborg/Uppsala University, Gävle, Sweden
| | - Tomasz Baron
- Department of Medical Sciences, Clinical Physiology and Cardiology, Uppsala University, Uppsala, Sweden
| | - Stellan Mörner
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Sven-Olof Granstam
- Department of Medical Sciences, Clinical Physiology and Cardiology, Uppsala University, Uppsala, Sweden
| | - Mark Lubberink
- Department of Surgical Sciences, Radiology & Nuclear Medicine, Uppsala University, Uppsala, Sweden
| | - Lars Tolbod
- Nuclear Medicine and PET, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jeffrey van den Berg
- Department of Surgical Sciences, Radiology & Nuclear Medicine, Uppsala University, Uppsala, Sweden
| | - Frank A Flachskampf
- Department of Medical Sciences, Clinical Physiology and Cardiology, Uppsala University, Uppsala, Sweden
| | - Tanja Kero
- Department of Surgical Sciences, Radiology & Nuclear Medicine, Uppsala University, Uppsala, Sweden
| | - Peter Magnusson
- Centre for Research and Development, Region Gävleborg/Uppsala University, Gävle, Sweden
- Cardiology Research Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Hendrik J Harms
- Department of Surgical Sciences, Radiology & Nuclear Medicine, Uppsala University, Uppsala, Sweden
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Clemmensen TS, Eiskjær H, Ladefoged B, Mikkelsen F, Sørensen J, Granstam SO, Rosengren S, Flachskampf FA, Poulsen SH. Prognostic implications of left ventricular myocardial work indices in cardiac amyloidosis. Eur Heart J Cardiovasc Imaging 2021; 22:695-704. [PMID: 32529207 DOI: 10.1093/ehjci/jeaa097] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 03/01/2020] [Indexed: 01/08/2023] Open
Abstract
AIMS Left ventricular (LV) myocardial work index (LVMWI) derived from pressure-strain analysis resembles a novel non-invasive method for LV function evaluation. LV global longitudinal strain (LVGLS) has proven beneficial for risk stratification in cardiac amyloidosis (CA) patients. This study aimed to evaluate the potential additive value of LVMWI for outcome prediction in CA patients. METHODS AND RESULTS We enrolled 100 CA patients in the period 2014-19 from Aarhus University Hospital, Denmark and Uppsala University Hospital, Sweden. All patients underwent comprehensive echocardiographic evaluation and were prospectively followed until censuring date on 31 March 2019 or death. During follow-up, we registered major adverse cardiac events (MACE) comprising heart failure requiring hospitalization and all-cause mortality. The median follow-up was 490 (228-895) days. During follow-up, a total of 42% of patients experienced MACE and 29% died. Patients with LVMWI <1043 mmHg% had higher MACE risk than patients with LVMWI >1043 mmHg% [hazard ratio (HR) 2.3, 95% confidence interval (CI) 1.2-4.3; P = 0.01]. Furthermore, patients with LVMWI <1039 mmHg% also had higher all-cause mortality risk than patients with LVMWI >1039 mmHg% (HR 2.6, 95% CI 1.2-5.5; P < 0.05). Moreover, the apical-to-basal segmental work ratio was a significant MACE and all-cause mortality predictor. By combining LVMWI and apical-to-basal segmental work ratio, we obtained an independent model for all-cause mortality prediction (high vs. low risk: HR 6.4, 95% CI 2.4-17.1; P < 0.0001). In contrast, LVGLS did not predict all-cause mortality. CONCLUSION LV myocardial work may be of prognostic value in CA patients by predicting both MACE and all-cause mortality.
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Affiliation(s)
- Tor Skibsted Clemmensen
- Department of Cardiology, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Hans Eiskjær
- Department of Cardiology, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Bertil Ladefoged
- Department of Cardiology, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Fabian Mikkelsen
- Department of Cardiology, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Jens Sørensen
- Department of Nuclear Medicine & PET Center, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.,Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala University, Akademiska sjukhuset, 751 85, Uppsala, Sweden
| | - Sven-Olof Granstam
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Akademiska sjukhuset, 751 85, Uppsala, Sweden
| | - Sara Rosengren
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Akademiska sjukhuset, 751 85, Uppsala, Sweden
| | - Frank A Flachskampf
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Akademiska sjukhuset, 751 85, Uppsala, Sweden.,Department of Cardiology, Akademiska Sjukhuset, Akademiska sjukhuset, 751 85, Uppsala, Sweden
| | - Steen Hvitfeldt Poulsen
- Department of Cardiology, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
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Rosengren S, Skibsted Clemmensen T, Tolbod L, Granstam SO, Eiskjær H, Wikström G, Vedin O, Kero T, Lubberink M, Harms HJ, Flachskampf FA, Baron T, Carlson K, Mikkelsen F, Antoni G, Frost Andersen N, Hvitfeldt Poulsen S, Sörensen J. Diagnostic Accuracy of [11C]PIB Positron Emission Tomography for Detection of Cardiac Amyloidosis. JACC Cardiovasc Imaging 2020; 13:1337-1347. [DOI: 10.1016/j.jcmg.2020.02.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 12/11/2022]
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Clemmensen TS, Eiskjær H, Mikkelsen F, Granstam SO, Flachskampf FA, Sørensen J, Poulsen SH. Left Ventricular Pressure-Strain-Derived Myocardial Work at Rest and during Exercise in Patients with Cardiac Amyloidosis. J Am Soc Echocardiogr 2020; 33:573-582. [PMID: 32061410 DOI: 10.1016/j.echo.2019.11.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 02/01/2023]
Abstract
BACKGROUND Left ventricular pressure-strain-derived myocardial work index (LVMWI) is a novel, noninvasive method for left ventricular (LV) function evaluation in relation to LV pressure dynamics. LV global longitudinal strain (LVGLS) has proven benefit for diagnosis and risk stratification in patients with cardiac amyloidosis (CA), but LVGLS does not adjust for loading conditions. The aim of the present study was to characterize LVMWI at rest and during exercise in patients with CA. METHODS A total of 155 subjects were retrospectively included. These subjects comprised 100 patients with CA and 55 healthy control subjects. All patients had previously undergone comprehensive two-dimensional echocardiographic examinations at rest. Furthermore, a subgroup 27 patients with CA and 41 control subjects was examined using semisupine exercise stress echocardiography. RESULTS Patients with CA had significantly lower LVGLS, LVMWI, and LV myocardial work efficiency (LVMWE) than control subjects (P < .0001 for all). The reduction in LV myocardial performance was more pronounced in the basal segments, which led to significant alterations in the average apical-to-basal segmental ratios between patients with CA and control subjects (LVGLS, 2.6 [1.9 to 4.1] vs 1.3 [1.2 to 1.5]; LVMWI, 2.6 [1.7 to 3.8] vs 1.3 [1.1 to 1.5]; LVMWE, 1.1 [1.0 to 1.3] vs 1.0 [1.0 to 1.1]; P < .0001 for all). The average increase in LVMWI from rest to peak exercise was 1,974 mm Hg% (95% CI, 1,699 to 2,250 mm Hg%; P < .0001) in control subjects and 496 mm Hg% (95% CI, 156 to 835 mm Hg%; P < .01) in patients with CA. The absolute numeric LVGLS increase was 5.6% (95% CI, 3.9% to 7.3%; P < .0001) in control subjects and only 1.2% (95% CI, -0.9% to 3.3%; P = .26) in patients with CA (between groups, P < .0001) from rest to peak exercise. The LVMWI increase in patients with CA was mediated by improvement in the apical segments (P < .0001), whereas there was no significant LVMWI alterations in the midventricular or basal segments. LVMWE remained stable during exercise in control subjects (Δ -0.6%; 95% CI, -2.5% to 1.2%; P = .50) but decreased significantly in patients with CA (Δ -2.5%; 95% CI, -4.8% to -0.2%; P < .05). CONCLUSIONS Patients with CA have significantly reduced magnitude of LVMWI compared with healthy control subjects. With exercise, the differences are even more pronounced. Even though LVMWI increased with exercise, LVMWE decreased, suggesting inefficient myocardial energy exploitation in patients with CA.
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Affiliation(s)
| | - Hans Eiskjær
- Department of Cardiology, Aarhus University Hospital, Skejby, Denmark
| | - Fabian Mikkelsen
- Department of Cardiology, Aarhus University Hospital, Skejby, Denmark
| | - Sven-Olof Granstam
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden
| | - Frank A Flachskampf
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden; Department of Cardiology, Akademiska Sjukhuset, Uppsala, Sweden
| | - Jens Sørensen
- Department of Nuclear Medicine & PET Center, Aarhus University Hospital, Skejby, Denmark; Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
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Rosengren S, Skibsted Clemmensen T, Tolbod L, Granstam SO, Eiskjaer H, Wikstrom G, Vedin O, Kero T, Lubberink M, Harms HJ, Flachskampf FA, Antoni G, Frost Andersen N, Hvitfeldt Poulsen S, Sorensen J. 37Diagnostic accuracy of [11C]PIB positron emission tomography for detection of cardiac amyloidosis. Eur Heart J Cardiovasc Imaging 2019. [DOI: 10.1093/ehjci/jez135.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- S Rosengren
- Uppsala University, Department of Medical Sciences, Haematology, Uppsala, Sweden
| | | | - L Tolbod
- Aarhus University Hospital, Department of Nuclear Medicine and PET, Aarhus, Denmark
| | - S O Granstam
- Uppsala University, Department of Medical Sciences, Clinical Physiology, Uppsala, Sweden
| | - H Eiskjaer
- Aarhus University Hospital, Department of Cardiology, Aarhus, Denmark
| | - G Wikstrom
- Uppsala University, Department of Medical Sciences, Cardiology, Uppsala, Sweden
| | - O Vedin
- Uppsala University, Department of Medical Sciences, Cardiology, Uppsala, Sweden
| | - T Kero
- Uppsala University, Department of Surgical Sciences, Radiology, Uppsala, Sweden
| | - M Lubberink
- Uppsala University, Department of Surgical Sciences, Radiology, Uppsala, Sweden
| | - H J Harms
- Aarhus University Hospital, Department of Nuclear Medicine and PET, Aarhus, Denmark
| | - F A Flachskampf
- Uppsala University, Department of Medical Sciences, Clinical Physiology, Uppsala, Sweden
| | - G Antoni
- Uppsala University, Department of Medical Chemistry, Uppsala, Sweden
| | - N Frost Andersen
- Aarhus University Hospital, Department of Haematology, Aarhus, Denmark
| | | | - J Sorensen
- Uppsala University, Department of Surgical Sciences, Radiology, Uppsala, Sweden
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Sorensen J, Harms HJ, Wikstrom G, Pilebro B, Vedin O, Granstam SO, Rosengren S. 240Symptomatic transthyretin cardiac amyloidosis is associated with chronic myocardial ischemia at rest and early death. Eur Heart J Cardiovasc Imaging 2019. [DOI: 10.1093/ehjci/jez145.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- J Sorensen
- Uppsala University, Surgical Sciences, Nuclear Medicine, Uppsala, Sweden
| | - H J Harms
- Aarhus University, Clinical Institute, Aarhus, Denmark
| | - G Wikstrom
- Uppsala University, Medical sciences, Uppsala, Sweden
| | - B Pilebro
- Umea University Hospital, Cardiology, Umea, Sweden
| | - O Vedin
- Uppsala University, Medical sciences, Uppsala, Sweden
| | - S O Granstam
- Uppsala University, Medical sciences, Uppsala, Sweden
| | - S Rosengren
- Uppsala University, Medical sciences, Uppsala, Sweden
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Henrohn D, Björkstrand K, Lundberg JO, Granstam SO, Baron T, Ingimarsdóttir IJ, Hedenström H, Malinovschi A, Wernroth ML, Jansson M, Hedeland M, Wikström G. Effects of Oral Supplementation With Nitrate-Rich Beetroot Juice in Patients With Pulmonary Arterial Hypertension-Results From BEET-PAH, an Exploratory Randomized, Double-Blind, Placebo-Controlled, Crossover Study. J Card Fail 2018; 24:640-653. [PMID: 30244181 DOI: 10.1016/j.cardfail.2018.09.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 09/06/2018] [Accepted: 09/13/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND The nitrate-nitrite-nitric oxide (NO) pathway may represent a potential therapeutic target in patients with pulmonary arterial hypertension (PAH). We explored the effects of dietary nitrate supplementation, with the use of nitrate-rich beetroot juice (BRJ), in patients with PAH. METHODS AND RESULTS We prospectively studied 15 patients with PAH in an exploratory randomized, double-blind, placebo-controlled, crossover trial. The patients received nitrate-rich beetroot juice (∼16 mmol nitrate per day) and placebo in 2 treatment periods of 7 days each. The assessments included; exhaled NO and NO flow-independent parameters (alveolar NO and bronchial NO flux), plasma and salivary nitrate and nitrite, biomarkers and metabolites of the NO-system, N-terminal pro-B-type natriuretic peptide, echocardiography, ergospirometry, diffusing capacity of the lung for carbon monoxide, and the 6-minute walk test. Compared with placebo ingestion of BRJ resulted in increases in; fractional exhaled NO at all flow-rates, alveolar NO concentrations and bronchial NO flux, and plasma and salivary levels of nitrate and nitrite. Plasma ornithine levels decreased and indices of relative arginine availability increased after BRJ compared to placebo. A decrease in breathing frequency was observed during ergospirometry after BRJ. A tendency for an improvement in right ventricular function was observed after ingestion of BRJ. In addition a tendency for an increase in the peak power output to peak oxygen consumption ratio (W peak/VO2 peak) was observed, which became significant in patients reaching an increase of plasma nitrite >30% (responders). CONCLUSIONS BRJ administered for 1 week increases pulmonary NO production and the relative arginine bioavailability in patients with PAH, compared with placebo. An increase in the W peak/VO2 peak ratio was observed after BRJ ingestion in plasma nitrite responders. These findings indicate that supplementation with inorganic nitrate increase NO synthase-independent NO production from the nitrate-nitrite-NO pathway.
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Affiliation(s)
- Dan Henrohn
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden.
| | - Kristoffer Björkstrand
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
| | - Jon O Lundberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Sven-Olof Granstam
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
| | - Tomasz Baron
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden; Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden; Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden
| | - Inga J Ingimarsdóttir
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
| | - Hans Hedenström
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
| | - Andrei Malinovschi
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
| | - Mona-Lisa Wernroth
- Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden; Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Martin Jansson
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
| | - Mikael Hedeland
- Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute, (SVA), Uppsala, Sweden; Division of Analytical Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Gerhard Wikström
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
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Leonard D, Svenungsson E, Sandling JK, Berggren O, Jönsen A, Bengtsson C, Wang C, Jensen-Urstad K, Granstam SO, Bengtsson AA, Gustafsson JT, Gunnarsson I, Rantapää-Dahlqvist S, Nordmark G, Eloranta ML, Syvänen AC, Rönnblom L. Coronary heart disease in systemic lupus erythematosus is associated with interferon regulatory factor-8 gene variants. ACTA ACUST UNITED AC 2013; 6:255-63. [PMID: 23661672 DOI: 10.1161/circgenetics.113.000044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Patients with systemic lupus erythematosus have increased morbidity and mortality in coronary heart disease (CHD). We asked whether there was a genetic influence on CHD in systemic lupus erythematosus. METHODS AND RESULTS The association between single-nucleotide polymorphisms (SNPs) and CHD in 2 populations of patients with systemic lupus erythematosus was assessed. Patients were genotyped on a custom 12k Illumina Array. The allele frequencies were compared between patients with (n=66) and without (n=509) CHD. We found 61 SNPs with an association (P<0.01) to CHD, with the strongest association for 3 SNPs located in the interferon regulatory factor-8 (IRF8) gene. Comparison of the allele frequencies of these 61 SNPs in patients with (n=27) and without (n=212) CHD in the second study population revealed that 2 SNPs, rs925994 and rs10514610 in IRF8 (linkage disequilibrium, r²=0.84), were associated with CHD in both study populations. Meta-analysis of the SNP rs925994 gave an odds ratio of 3.6 (2.1-6.3), P value 1.9×10⁻⁶. The identified IRF8 allele remained as a risk factor for CHD after adjustment for traditional CHD risk factors. The IRF8 risk allele was associated with the presence of carotid plaques (P<0.001) and increased intima-media thickness (P=0.01). By electrophoretic mobility shift assays, we show weaker binding of protein to the risk allele of the highly linked SNP rs11117415, and by flow cytometry, a reduced frequency of circulating B cells was detected in patients with the IRF8 risk allele. CONCLUSIONS There is a considerable genetic component for CHD in systemic lupus erythematosus, with IRF8 as a strong susceptibility locus.
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Affiliation(s)
- Dag Leonard
- Section of Rheumatology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
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Granstam SO, Rosengren S, Vedin O, Kero T, Sörensen J, Carlson K, Flachskampf FA, Wikström G. Evaluation of patients with cardiac amyloidosis using echocardiography, ECG and right heart catheterization. Amyloid 2013; 20:27-33. [PMID: 23339421 DOI: 10.3109/13506129.2012.761967] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS To characterize patients with cardiac amyloidosis using echocardiography, electrocardiogram (ECG) and right heart catheterization (RHC). METHODS AND RESULTS Fourteen patients with biopsy verified light chain or transthyretin cardiac amyloidosis were included. All patients had heart failure with markedly elevated NT-proBNP. Echocardiography demonstrated biventricular hypertrophy, left atrial enlargement and normal to slightly reduced left ventricular ejection fraction. Tissue Doppler septal é was low and median E/é was high. Within 6 months RHC was performed in eight of the patients. The restrictive filling pattern demonstrated by echocardiography corresponded well to median pulmonary wedge pressure (21 mmHg). Systolic pulmonary artery pressure (SPAP) was increased, whereas cardiac output and stroke volume were seen to be decreased with both methods. ECG demonstrated: low voltage (36%), abnormal R-progression (65%), ST-T abnormalities (71%) and high incidence of fibrillation (36%). In addition, a case report following the treatment of melphalan and dexamethasone is presented with improvement of hypertrophy, SPAP, left ventricular mass and é. CONCLUSION These findings should lead to a suspicion of cardiac amyloidosis and suggest further investigation.
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Affiliation(s)
- Sven-Olof Granstam
- Department of Medical Sciences: Clinical Physiology, Uppsala University, Uppsala, Sweden.
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Granstam SO, Björklund E, Wikström G, Roos MW. Use of echocardiographic pulmonary acceleration time and estimated vascular resistance for the evaluation of possible pulmonary hypertension. Cardiovasc Ultrasound 2013; 11:7. [PMID: 23445525 PMCID: PMC3600025 DOI: 10.1186/1476-7120-11-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 02/15/2013] [Indexed: 12/02/2022] Open
Abstract
Background During ultrasound examination, tricuspid regurgitation may be absent or gives a signal that is not reliable for the estimation of systolic pulmonary pressure. The aim of this study was to evaluate the usefulness of acceleration time (AT) from the right ventricular outflow tract (RVOT) as an estimation of the trans-tricuspid valve gradient (TTVG) and to investigate the correlation between estimated and invasive pulmonary vascular resistance (PVR). Methods The AT was correlated to the TTVG measured with routine standard echocardiography in 121 patients. In a subgroup of 29 patients, systolic pulmonary pressure (SPAP) and mean pulmonary arterial pressure (MPAP) were obtained from recent right heart catheterization (RHC). Results We found no significant correlation between the estimation of right atrial pressure (RAP) by echocardiography and the RAP obtained by RHC. Estimated SPAP (TTGV + RAP mean from RHC) showed a good linear relation to invasively measured SPAP. TTVG and AT showed a non-linear relation, similar to SPAP and MPAP measured by catheterization and AT. For detection of SPAP above 38 mmHg a cut-off for AT of 100 ms resulted in a sensitivity of 89% and a specificity of 84%. For detection of MPAP above 25 mmHg a cut-off for AT of 100 ms resulted in similar sensitivity and specificity. Invasive PVR and the ratio of TTVG and the time velocity integral of the RVOT (TVI RVOT ) had a strong linear relation. Conclusions Our study confirms that AT appears to be useful for the evaluation of pulmonary hypertension. In high risk patients, an AT of less than 100 ms indicates a high probability of pulmonary hypertension. Furthermore, PVR estimation by ultrasound seems preferably be done by using the ratio of TTVG and TVI RVOT.
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Affiliation(s)
- Sven-Olof Granstam
- Department of Medical Sciences Clinical Physiology, Uppsala University, Uppsala, Sweden.
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12
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Antoni G, Lubberink M, Estrada S, Axelsson J, Carlson K, Lindsjö L, Kero T, Långström B, Granstam SO, Rosengren S, Vedin O, Wassberg C, Wikström G, Westermark P, Sörensen J. In vivo visualization of amyloid deposits in the heart with 11C-PIB and PET. J Nucl Med 2012; 54:213-20. [PMID: 23238792 DOI: 10.2967/jnumed.111.102053] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Cardiac amyloidosis is a differential diagnosis in heart failure and is associated with high mortality. There is currently no noninvasive imaging test available for specific diagnosis. N-[methyl-(11)C]2-(4'-methylamino-phenyl)-6-hydroxybenzothiazole ((11)C-PIB) PET is used in the evaluation of brain amyloidosis. We evaluated the potential use of (11)C-PIB PET in systemic amyloidosis affecting the heart. METHODS Patients (n = 10) diagnosed with systemic amyloidosis-including heart involvement of either monoclonal immunoglobulin light-chain (AL) or transthyretin (ATTR) type-and healthy volunteers (n = 5) were investigated with PET/CT using (11)C-PIB to study cardiac amyloid deposits and with (11)C-acetate to measure myocardial blood flow to study the impact of global and regional perfusion on PIB retention. RESULTS Myocardial (11)C-PIB uptake was visually evident in all patients 15-25 min after injection and was not seen in any volunteer. A significant difference in (11)C-PIB retention in the heart between patients and healthy controls was found. The data indicate that myocardial amyloid deposits in patients diagnosed with systemic amyloidosis could be visualized with (11)C-PIB. No correlation between (11)C-PIB retention index and myocardial blood flow as measured with (11)C-acetate was found on the global level, whereas a positive correlation on the segmental level was seen in a single patient. CONCLUSION (11)C-PIB and PET could be a method to study systemic amyloidosis of type AL and ATTR affecting the heart and should be investigated further both as a diagnostic tool and as a noninvasive method for treatment follow-up.
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Affiliation(s)
- Gunnar Antoni
- Platform for Preclinical PET, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden.
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13
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Granstam SO, Granstam E. Endothelin-induced changes in blood flow in STZ-diabetic and non-diabetic rats: relation to nitric oxide synthase and cyclooxygenase inhibition. J Physiol Sci 2011; 61:497-505. [PMID: 21881977 PMCID: PMC3204103 DOI: 10.1007/s12576-011-0171-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/09/2011] [Indexed: 01/18/2023]
Abstract
In this study, using the microsphere method, the hemodynamic response to endothelin-1 (ET-1) in healthy and streptozotocin (STZ)-diabetic rats was evaluated as well as the influences of inhibition of nitric oxide (NO)-synthase using L-NAME (Nω-nitro-L: -arginine methyl ester) and the cyclooxygenase inhibitor indomethacin. Blood flow (Q) was measured in tissues of interest for vascular complications in diabetes such as kidney, eye, brain, heart and skeletal muscle with the main focus on ophthalmic circulation. Under resting conditions, evidence for renal vasoconstriction was found in diabetic animals. In both groups, administration of L-NAME reduced Q in all investigated tissues indicating a basal NO influence. In the normal rats, ET-1 induced a significant increase in blood pressure and intense vasoconstriction in all tissues except in the choroid of the eye and in the brain, where it induced an increased Q. In the STZ-diabetic rats, effects of ET-1 were less pronounced. Pretreatment with L-NAME, but not the cyclooxygenase inhibitor, abolished the ET-1-induced vasodilation in the choroid of both groups. Administration of ET A receptor antagonist BQ-123 reduced the ET-1-induced vasodilation in the choroid only in diabetic animals. In conclusion, evidence for altered vascular endothelial response to ET-1 in STZ-diabetic animals was found particularly in the ophthalmic circulation. The findings suggest differential involvement of receptors in the response to ET-1 in normal and STZ-diabetic animals.
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Affiliation(s)
- Sven-Olof Granstam
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden.
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Nordmark J, Johansson J, Sandberg D, Granstam SO, Huzevka T, Covaciu L, Mörtberg E, Rubertsson S. Assessment of intravascular volume by transthoracic echocardiography during therapeutic hypothermia and rewarming in cardiac arrest survivors. Resuscitation 2009; 80:1234-9. [PMID: 19716641 DOI: 10.1016/j.resuscitation.2009.06.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 05/13/2009] [Accepted: 06/07/2009] [Indexed: 10/20/2022]
Abstract
AIM To study haemodynamic effects and changes in intravascular volume during hypothermia treatment, induced by ice-cold fluids and maintained by ice-packs followed by rewarming in patients after resuscitation from cardiac arrest. MATERIALS AND METHODS In 24 patients following successful restoration of spontaneous circulation (ROSC), hypothermia was induced with infusion of 4 degrees C normal saline and maintained with ice-packs for 26 h after ROSC. This was followed by passive rewarming. Transthoracic echocardiography was performed at 12, 24 and 48 h after ROSC to evaluate ejection fraction and intravascular volume status. Central venous pressure (CVP), central venous oxygen saturation (ScvO(2)) and serum lactate were measured. Fluid balance was calculated. RESULTS Twelve hours after ROSC, two separate raters independently estimated that 10 and 13 out of 23 patients had a decreased intravascular volume using transthoracic echocardiography. After 24 and 48 h this number had increased further to 14 and 13 out of 19 patients and 13 and 12 out of 21 patients. Calculated fluid balance was positive (4000 ml the day 1 and 2500 ml day 2). There was no difference in ejection fraction between the recording time points. Serum lactate and ScvO(2) were in the normal range when echocardiography exams were performed. CVP did not alter over time. CONCLUSIONS Our results support the hypothesis that inducing hypothermia following cardiac arrest, using cold intravenous fluid infusion does not cause serious haemodynamic side effects. Serial transthoracic echocardiographic estimation of intravascular volume suggests that many patients are hypovolaemic during therapeutic hypothermia and rewarming in spite of a positive fluid balance.
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Affiliation(s)
- Johanna Nordmark
- Department of Surgical Sciences/Anaesthesiology, Intensive Care, Uppsala University, Sweden.
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15
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Granstam SO, Ljunghusen J. [Bedside echocardiography opens new possibilities for emergency care]. Lakartidningen 2003; 100:2624-5. [PMID: 12968326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
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Lind L, Granstam SO, Millgård J. Endothelium-dependent vasodilation in hypertension: a review. Blood Press 2000; 9:4-15. [PMID: 10854002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Using both in vitro and in vivo techniques, it has repeatedly been shown that endothelium-dependent vasodilation (EDV) is impaired in different forms of experimental hypertension (SHR, Dahl salt-sensitive rat, DOCA-salt rat and renovascular hypertension). EDV has also been found to be impaired in primary, as well as in secondary forms of human hypertension. Although impaired EDV is a general finding in hypertension, the pathophysiological mechanisms might differ between different forms of hypertension and between different types of vessels and vascular beds. Impaired activity of nitric oxide synthase, increased release of endothelin-1, increased production of a prostanoid-derived contracting factor, decreased generation of endothelium-derived hyperpolarizing factor/s and impairment caused by superoxide ions have all been shown to contribute to the impairment of EDV during different conditions. While most antihypertensive treatments improve EDV in experimental hypertension, no uniform picture has been seen in human hypertension, possibly because different antihypertensive drugs have different direct actions on EDV. This review shows that while impaired EDV has been found to be a general feature of hypertension, the mechanisms involved and the therapeutic opportunities have still to be established.
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Affiliation(s)
- L Lind
- Department of Medicine, University Hospital, Uppsala, Sweden
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17
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Abstract
PURPOSE In experimental and human diabetes mellitus evidence for an impaired function of the vascular endothelial cells has been found. The purpose of the present experiments was to measure uveal and retinal blood flow and vascular resistance at an early stage of experimental diabetes mellitus and to evaluate the effects of acetylcholine and L-arginine in control and L-NAME-pretreated animals. METHOD The radioactively labelled microsphere method was applied to normal Sprague-Dawley rats and rats with STZ-induced diabetes of three weeks duration. RESULTS In the present study, similar blood flow and vascular resistance were observed in the uvea of normal and STZ-diabetic rats. Evidence for a basal vasodilating NO-tone was found both in the uvea and in the retina of both groups. In the normal rats as well as in the diabetic animals, acetylcholine induced choroidal vasodilation. Local blood flow increased from 54 +/- 17 to 142 +/- 32 mg x min(-1) in normal rats and from 57 +/- 18 to 112 +/- 23 mg x min(-1) in diabetic rats (P < 0.05 respectively). No hemodynamic changes were observed in the anterior uvea, demonstrating a difference in reactivity between these vascular beds. In animals pretreated with the NO-synthase inhibitor L-NAME, acetylcholine did not significantly affect local blood flow in the choroid, suggesting NO as a mediator of the vasodilation. CONCLUSION The results indicate a normal action of NO in the ocular vascular beds at this stage of experimental diabetes mellitus in the rat.
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Affiliation(s)
- E Granstam
- Department of Neuroscience/Ophthalmology, University Hospital, Uppsala, Sweden.
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18
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Granstam SO, Granstam E, Fellström B, Lind L. Effects of endothelin receptor type A antagonism and nitric oxide synthase inhibition on cerebral blood flow in hypertensive rats. Acta Physiol Scand 1998; 164:213-8. [PMID: 9805108 DOI: 10.1046/j.1365-201x.1998.00419.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Effects of the endothelin receptor type A antagonist BQ 123 and the NO synthase inhibitor L-NMMA on cerebral blood flow were studied in vivo in anaesthetized hypertensive (SHR) and normotensive (WKY) rats. The effects of acetylcholine following pre-treatment with these drugs were also studied with the microsphere method for blood flow determination in the cortex, thalamus, caudatus, pons, medulla, cerebellum and hypophysis. BQ 123 (1 mg kg-1) induced only minor effects on cerebral blood flow in both strains (n = 8), whereas L-NMMA (N = 8; 20 mg kg-1) reduced regional cerebral blood flow significantly in most regions (21-54%) in the hypertensive, but not in the normotensive rat. In normotensive rats pre-treated with BQ 123 intravenous administration of acetylcholine (2 micrograms kg-1 min-1) induced a widespread significant increase (20-50%) in cerebral blood flow despite a reduction of the mean arterial blood pressure, while no significant effects were seen in hypertensive animals. Intravenous infusion of acetylcholine in animals pre-treated with L-NMMA did not affect cerebral blood flow in most regions in either of the two rat strains. In conclusion, a vasodilatory response to acetylcholine was found following endothelin receptor A antagonism in the WKY rat only, suggesting a role for endothelin in the control of cerebral blood flow in this strain. Furthermore, a higher basal vasodilating nitric oxide-tone seems to be present in the hypertensive rat compared with the normotensive rat.
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Affiliation(s)
- S O Granstam
- Department of Internal Medicine, University of Uppsala, Sweden
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Granstam SO, Fellström B, Lind L. Influences of carvedilol treatment on the effects of acetylcholine on regional haemodynamics in the spontaneously hypertensive rat. Clin Sci (Lond) 1998; 95:303-9. [PMID: 9730849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
1. In a previous report, we have shown that vasodilatation induced by acetylcholine is impaired in the kidney and the heart of the spontaneously hypertensive rat (SHR) in vivo. The present investigation was performed to study the influence of oral antihypertensive treatment with carvedilol for 6 to 10 weeks on acetylcholine-induced changes in regional haemodynamics in SHR in vivo. Cardiac output, regional blood flow and vascular resistance in organs of major importance in hypertensive disease, such as the kidney, heart, skeletal muscle, brain and eye, were measured with radioactively labelled microspheres in anaesthetized rats (aged 12-16 weeks).2. Mean arterial blood pressure was significantly lower in the carvedilol-treated SHR group (156+/-3 mmHg, n=17) than in an untreated SHR group (172+/-6 mmHg, n=13). Infusion of acetylcholine (2 microgram.min-1.kg-1) caused similar significant reductions in blood pressure in the two groups (-13+/-1% and -14+/-2%). However, acetylcholine induced a significant increase in total peripheral vascular resistance in the carvedilol group (29+/-10%, P<0.01), whereas no significant change was observed in the control group (0+/-11%).3. Acetylcholine significantly increased renal vascular resistance in the carvedilol group (+62+/-15%, P<0.01), but did not change vascular resistance in the control group (-6+/-6%). In the heart, acetylcholine did not affect vascular resistance in the carvedilol group, but reduced vascular resistance significantly in the control group (-17+/-8%, P<0.05). The circulatory changes induced by acetylcholine in the skeletal muscle, brain and ophthalmic circulation did not differ between the groups.4. In conclusion, the results demonstrate that long-term oral carvedilol treatment in the SHR did not enhance acetylcholine-induced vasodilatation, but instead pronounced renal vasoconstriction was induced by acetylcholine, which could partly be due to a decreased cardiac index.
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Affiliation(s)
- S O Granstam
- Department of Medicine, University Hospital of Uppsala, 75185 Uppsala, Sweden
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Granstam SO, Lind L, Granstam E, Fellström B. Effects of nitric oxide synthase inhibition and endothelin ETA receptor blockade on haemodynamics in hypertensive rats. Clin Exp Pharmacol Physiol 1998; 25:693-701. [PMID: 9750958 DOI: 10.1111/j.1440-1681.1998.tb02278.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. The objectives of the present study were to study regional differences in haemodynamics between spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats induced by the nitric oxide synthase (NOS) inhibitor NG-monomethyl-L-arginine (L-NMMA) and the endothelin ETA receptor antagonist BQ 123 in vivo in tissues known to be important for blood pressure (BP) regulation (heart, kidney and skeletal muscle). Furthermore, the effect of acetylcholine (ACh) infusion (2 micrograms/kg per min) was examined after L-NMMA or BQ 123. The microsphere method was used for determinations of cardiac index (CI) and regional haemodynamics. 2. NG-Monomethyl-L-arginine (20 mg/kg) increased BP (26-48%; P < 0.01) and reduced CI in both rat strains. BQ 123 (1 mg/kg) reduced BP slightly (-4 to 11%; P < 0.05). 3. NG-Monomethyl-L-arginine significantly increased myocardial and skeletal muscle vascular resistance in SHR only; however, in the kidney, L-NMMA reduced blood flow and increased vascular resistance in both rat strains. 4. BQ 123 induced minor changes in regional haemodynamics that were not significantly different between the two strains. 5. Acetylcholine following BQ 123 induced an increase in myocardial blood flow in WKY rats, but decreased blood flow in SHR. Acetylcholine following L-NMMA reduced myocardial blood flow in both strains. 6. Acetylcholine following BQ 123 induced renal vasodilation in WKY rats but, following L-NMMA, ACh did not induce renal vasodilation in either rat strain. In contrast, L-NMMA did not abolish the vasodilation of acetylcholine in skeletal muscle in WKY rats. 7. In conclusion, the contribution of nitric oxide to basal vessel tone was not impaired in the heart, skeletal muscle and kidney in SHR. Antagonism of ETA receptors caused similar haemodynamic responses in both rat strains in these organs. Furthermore, NOS inhibition, but not ETA blockade, blunted the expected ACh-induced vasodilation in the heart and kidney in WKY rats, but not in skeletal muscle in both strains.
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Affiliation(s)
- S O Granstam
- Department of Internal Medicine, University Hospital, Uppsala, Sweden.
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21
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Granstam SO, Granstam E, Fellström B, Lind L. Regional haemodynamic differences between normotensive and spontaneously hypertensive rats--a microsphere study. Physiol Res 1998; 47:9-15. [PMID: 9708695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The objective of the present study was to compare systemic and regional haemodynamics in a large series of spontaneously hypertensive rats (SHR, n=32) with normotensive Wistar-Kyoto rats (WKY, n=26) at the age of 12-16 weeks. All rats were anaesthetized with thiobutabarbital and the radioactively labelled microsphere method was used to evaluate regional blood flow with special emphasis on different cerebral areas. The high blood pressure in the SHR was mainly due to elevated total peripheral resistance, which was 90% higher in the SHR compared to the WKY. Furthermore, heart rate was 25% (p<0.001) higher, but the cardiac index was lower by 20% (p<0.01) in the SHR. Blood flow was significantly lower and vascular resistance higher in several organs such as the kidneys, other visceral organs, skeletal muscle and skin of the SHR compared to the WKY. On the contrary, blood flow in the myocardium was augmented by 40% (p<0.01) in the SHR. Blood flow was 20-50% higher in the cerebral cortex, thalamus and caudatus (p<0.05-0.001), but attenuated in the hypophysis of the SHR. In the pons, medulla and cerebellum, blood flow was similar in the two strains. In this large microsphere study, the basal cardiac index was lower in the SHR already at this relatively early stage of established hypertension. Despite this, increased blood flow in the above mentioned cerebral regions was found in the SHR compared to the WKY.
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Affiliation(s)
- S O Granstam
- Department of Internal Medicine, University Hospital, Uppsala, Sweden
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22
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Abstract
PURPOSE The effects of endothelium-related substances such as acetylcholine, a stimulator of endogenous NO-production, the NO-synthesis inhibitor L-NMMA, the exogenous NO-donor sodium nitroprusside and the endothelin (ET)A-receptor antagonist BQ123, on uveal blood flow were investigated in normotensive and hypertensive SHR rats. METHOD The radioactively-labelled microsphere method was applied for the measurement of regional blood flow in the uvea. RESULTS Under resting conditions, local blood flow was lower in the hypertensive animals. The increase in choroidal blood flow (145 +/- 50%; P < 0.01) and reduction in vascular resistance (-58 +/- 7%; P < 0.01) observed in the WKY after i.v. infusion of acetylcholine, 2 micrograms x kg bw-1 x min-1, were significantly less pronounced in animals pretreated with L-NMMA, indicating local formation of NO as a vasodilator mechanism. In contrast, acetylcholine did not induce significant vasodilation in the choroid of SHR rats. In the anterior uvea of both strains, acetylcholine did not affect local blood flow. L-NMMA, 20 mg x kg bw-1, alone reduced blood flow in the entire uvea of both strains. Intravenous injection of BQ123, 1 mg x kg bw-1, did not affect regional blood flow in the uvea of WKY or SHR animals. Infusion of acetylcholine following ETA-receptor blockade induced vasodilation in both the choroid and anterior uvea in the WKY but not in the SHR. CONCLUSIONS Acetylcholine-stimulated NO-mediated vasodilation, but not basal NO-formation, was impaired in the choroid of the SHR. Furthermore, an interaction between vasoconstricting ET and acetylcholine was found in the anterior uvea of normotensive but not hypertensive rats.
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Affiliation(s)
- E Granstam
- Department of Ophthalmology, University Hospital of Uppsala, Sweden.
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23
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Granstam SO, Granstam E, Fellström B, Lind L. Effects of acetylcholine and nitroprusside on systemic and regional hemodynamics in hypertensive rats. Clin Exp Hypertens 1998; 20:223-43. [PMID: 9533615 DOI: 10.3109/10641969809053216] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study was performed to investigate the in vivo effects of acetylcholine, a stimulator of endogenous NO production, and nitroprusside, an exogenous NO-donor, on hemodynamics in the normotensive (WKY) and the hypertensive (SHR) rat. Anesthetized rats were given microspheres for the measurement of cardiac index (CI), total vascular resistance (TPRI), regional blood flow and vascular resistance. Infusion of acetylcholine (2 microg/kg/min) caused a marked decrease in TPRI by (-35+/-5%, +/-SEM) in the WKY (n=8), whereas in the SHR (n=8) a less pronounced reduction was seen (-14+/-3%, p<0.01 between groups). CI increased by 27+/-9% in the WKY, but was unaltered in the SHR. Blood pressure decreased similarly (17-20%). Acetylcholine significantly increased blood flow by about 40% in the kidneys and the heart in the WKY, but had no significant effect in the SHR. Other tissues, such as skeletal muscle and cerebral tissues, showed no major changes. Infusion of nitroprusside (1 microg/kg/min) reduced blood pressure by 5 to 10% in the strains. The regional effects of nitroprusside did not differ between the strains. In conclusion, the acetylcholine-induced vasodilation in the kidney and the heart was attenuated in the SHR compared to the WKY. These findings might suggest a difference in the endothelial response between the SHR and the WKY in some, but not in all, tissues.
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Affiliation(s)
- S O Granstam
- Department of Internal Medicine, University Hospital of Uppsala, Sweden
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Granstam SO, Jönson C, Fändriks L, Holm L, Flemström G. Effects of cigarette smoke and nicotine on duodenal bicarbonate secretion in the rabbit and the rat. J Clin Gastroenterol 1990; 12 Suppl 1:S19-24. [PMID: 2212546 DOI: 10.1097/00004836-199001001-00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of short-time exposure to cigarette smoke on duodenal mucosal bicarbonate secretion were studied in anesthetized rabbits and rats. The bicarbonate secretion was measured by continuous titration of recirculating luminal perfusate. In artificially ventilated rabbits, intermittent exposure to cigarette smoke during two 10-min periods caused a marked (approximately 40%) decrease (p less than 0.01) in duodenal bicarbonate secretion. After the exposures, secretion gradually recovered and had returned to the pre-exposure rate after 50 min. The decrease in secretion was associated with decreases in heart rate (approximately 15%) and blood pressure (approximately 30%) that, however, were of shorter duration. Neither reduced amounts of smoke (1/6 or 1/3) nor nicotine (25-1,000 micrograms/kg, intravenously) had any major effect on the bicarbonate secretion. In the spontaneously breathing rat, smoke was administered for 1-2 breaths every 30 s during a 5-min period. This exposure resulted in a significant (p less than 0.05) decrease in bicarbonate secretion and some increase in the blood pressure. Exposure to smoke had no effect on the secretion in rats with both splanchnic nerves cut, suggesting neural sympathetic mediation of the smoke-induced inhibition.
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Affiliation(s)
- S O Granstam
- Department of Physiology and Medical Biophysics, Uppsala University, Sweden
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Granstam SO, Flemström G, Nylander O. Bicarbonate secretion by the rabbit duodenum in vivo: effects of prostaglandins, vagal stimulation and some drugs. Acta Physiol Scand 1987; 131:377-85. [PMID: 2892345 DOI: 10.1111/j.1748-1716.1987.tb08253.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Duodenal HCO-3 secretion in anaesthetized rabbits was measured by continuous titration of the recirculating luminal perfusate at pH 7.4. The segment under study started 3-4 cm distal to the pylorus and was devoid of pancreatic and biliary HCO-3 secretion. On histological examination the submucosa was seen to contain Brunner's glands, mainly of a mucous type. Duodenum in rabbit secreted HCO3- at a considerably higher basal rate (100-125 mu equiv h-1 cm-1 of intestine) than has previously been found in the rat, cat or dog. The cyclo-oxygenase inhibitor indomethacin (20 mg kg-1) reduced the secretion by 30%, while prostaglandin E2 (5-80 microM, luminal) caused a dose-dependent increase. Prostaglandins thus seem to be important in regulation of duodenal HCO3- secretion in the rabbit and may play a role in duodenal protection against acid. Carbachol (1 and 10 micrograms kg-1) and atropine (0.5 and 1 mg kg-1) had no effects whereas hexamethonium (10 mg kg-1) caused a persistent decrease (25%) in secretion. Effects of electrical stimulation of the vagal nerves or injection of the alpha 2-adrenergic agonist clonidine markedly depended on the agent used for anaesthesia. In urethane-anaesthetized animals, clonidine (0.75-75 micrograms kg-1) tended to increase the secretion whereas with nembutal, clonidine (5-150 micrograms kg-1) decreased it significantly. Electrical stimulation of the cervical vagal nerves decreased the HCO3- secretion in urethane-anaesthetized animals but had no significant effect during nembutal anaesthesia. The responses in the nembutal-anaesthetized rabbit are similar to those previously observed in the cat, rat or dog.
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Affiliation(s)
- S O Granstam
- Department of Physiology and Medical Biophysics, Uppsala University Biomedical Center, Sweden
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