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Braga TC, de Jesus ICG, Soares KV, Guatimosim S, da Silva Neto L, da-Silva CJ, Modolo LV, Menezes Filho JER, Rhana P, Cruz JS, de Fátima Â. A novel H2S releasing-monastrol hybrid (MADTOH) inhibits L-type calcium channels. NEW J CHEM 2021. [DOI: 10.1039/d0nj04415f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A new alleged monastrol-H2S releasing hybrid, named MADTOH, was designed based on the structure of monastrol (M) and 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADTOH) and synthesized in 7.8% overall yield.
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Affiliation(s)
| | - Itamar Couto Guedes de Jesus
- Departamento de Fisiologia e Biofísica
- Instituto de Ciências Biológicas
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | | | - Silvia Guatimosim
- Departamento de Fisiologia e Biofísica
- Instituto de Ciências Biológicas
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | | | - Cristiane Jovelina da-Silva
- Departamento de Botânica
- Instituto de Ciências Biológicas
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Luzia Valentina Modolo
- Departamento de Botânica
- Instituto de Ciências Biológicas
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | | | - Paula Rhana
- Departamento de Bioquímica e Imunologia
- Instituto de Ciências Biológicas
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Jader Santos Cruz
- Departamento de Bioquímica e Imunologia
- Instituto de Ciências Biológicas
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Ângelo de Fátima
- Departamento de Química
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
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2
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Wang Y, Hu YC, Zhou Y, Zhao L, Chen D, Li LL, Jiang L, Zhang ZC, Li SN, Wen SN, Ruan YF, Liu N, Qiao Y, Lv Q, Hu R, Du X, Liu XH, Ma CS, Dong JZ, Bai R. Relationship between coronary artery calcification and calcium deposition in the myocardium. J Int Med Res 2019; 47:2910-2920. [PMID: 31117861 PMCID: PMC6683874 DOI: 10.1177/0300060519848587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Objectives To investigate the relationship between coronary artery calcification and calcium deposition in cardiomyocytes. Methods Patients who underwent valve replacement plus surgical ablation for atrial fibrillation, together with left atrial appendage resection, were included. Coronary artery calcification (CAC) score was evaluated prior to surgery using dual-source computed tomography. Samples of left atrial appendage tissue were collected to analyse the following indicators: calcium deposition, alkaline phosphatase activity, calcium content, protein levels of runt-related transcription factor 2 (Runx2), osteopontin and β-catenin, and mRNA levels of osteopontin, endothelin and ghrelin. Relationships between CAC score and various indicators were analysed by univariate logistic or linear regression. Results Out of tissue from eight patients, CAC score was not correlated with cardiomyocyte calcification (odds ratio [OR] 0.984 and OR 0.983; von Kossa or alizarin red staining, respectively). CAC score showed an inverse linear correlation with Runx2 protein (β = –0.75), but was not correlated with osteopontin (β = –0.52) or β-catenin protein (β = –0.56), mRNA levels of osteopontin, endothelin and ghrelin (β = 0.13, 0.02, and 0.02, respectively), alkaline phosphatase activity (β = 0.56), or calcium content (β = –0.22). Conclusions Coronary artery calcification was not correlated with calcium deposition in cardiomyocytes.
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Affiliation(s)
- Yue Wang
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Yu-Cai Hu
- 2 Department of Cardiology, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou, China
| | - Yuan Zhou
- 3 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Lei Zhao
- 4 Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Dong Chen
- 5 Department of Pathology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Lin-Ling Li
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Le Jiang
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Zi-Chuan Zhang
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Song-Nan Li
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Song-Nan Wen
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Yan-Fei Ruan
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Nian Liu
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Yan Qiao
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Qiang Lv
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Rong Hu
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Xin Du
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Xiao-Hui Liu
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Chang-Sheng Ma
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Jian-Zeng Dong
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
| | - Rong Bai
- 1 Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Centre for Cardiovascular Diseases, Beijing, China
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3
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Quadri JA, Sarwar S, Pinky, Kar P, Singh S, Mallick SR, Arava S, Nag TC, Roy TS, Shariff A. Fluoride induced tissue hypercalcemia, IL-17 mediated inflammation and apoptosis lead to cardiomyopathy: Ultrastructural and biochemical findings. Toxicology 2018; 406-407:44-57. [PMID: 29800585 DOI: 10.1016/j.tox.2018.05.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 02/09/2023]
Abstract
An increased prevalence of cardiac complications has been observed in residents of fluorosis endemic areas chronically exposed to fluoride. Fluoride induces soft tissue injury due to oxidative stress, lipid peroxidation (LPO) and mitochondriopathy. It was hypothesized that chronic fluoride exposure induces apoptosis in cardiomyocytes due to inflammation, lysis of extra cellular matrix and altered calcium metabolism. This study was planned to evaluate the effects of chronic fluoride exposure and the mechanism of action in the cardiac muscle. Fifteen week old male Wistar rats were administered a human equivalent dose of fluoride (50 and 100 ppm ad-libitum, HED = 5 & 10 ppm in human) for 75-days. After 75-days of fluoride exposure, the animals were euthanized and fluoride, oxidative stress (SOD, GPX, Catalase activities) and LPO were measured. Histopathological and ultrastructural pathological examinations were conducted on the cardiac tissues using light, atomic force and electron microscopies. The cardiac tissues were also assessed for apoptosis (TUNEL/Caspase assays), and tissue calcium levels (Alizarin-assay and SEM-EDX). Tissue inflammation and expression of IL-17, MMP-9, Caspase-3 and Bcl-2 were evaluated. In the fluoride exposed groups, a significant (≤0.05) increase in levels of oxidative stress, LPO and apoptosis were observed. The IL-17, MMP-9 and Caspase-3 were significantly (≤0.05) higher in the cardiac muscle after chronic fluoride exposure. The fluoride seems to have induced inflammation in the cardiac tissues, as well as an increase in tissue calcium (≤0.05). There was significant damage to cardiac muscle fibres including, thinning, distortion and neo-vasculogenesis following chronic fluoride exposure. Mitochondriopathy, lysis of ground substance, oedema, and hyper-vacuolation was seen in fluoride treated groups. Remarkable levels of distortion and bending in Z band were observed under the AFM. Many of these observed changes mimic those occurring in cardiomegaly, cardiac hypertrophy and cardiomyopathies.
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Affiliation(s)
| | - Saba Sarwar
- Department of Anatomy, AIIMS, New Delhi, India
| | - Pinky
- Department of Anatomy, AIIMS, New Delhi, India
| | - Parmita Kar
- Department of Endocrinology and Metabolism, AIIMS, New Delhi, India
| | - Seema Singh
- Department of Anatomy, AIIMS, New Delhi, India
| | | | | | | | | | - A Shariff
- Department of Anatomy, AIIMS, New Delhi, India
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4
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Yoshida K, Hasebe H, Tsumagari Y, Tsuneoka H, Ebine M, Uehara Y, Seo Y, Aonuma K, Takeyasu N. Comparison of Pulmonary Venous and Left Atrial Remodeling in Patients With Atrial Fibrillation With Hypertrophic Cardiomyopathy Versus With Hypertensive Heart Disease. Am J Cardiol 2017; 119:1262-1268. [PMID: 28214001 DOI: 10.1016/j.amjcard.2016.12.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 10/20/2022]
Abstract
Left ventricular diastolic dysfunction in hypertrophic cardiomyopathy (HC) increases susceptibility to atrial fibrillation. Although phenotypical characteristics of the hypertrophied left ventricle are clear, left atrial (LA) and pulmonary venous (PV) remodeling has rarely been investigated. This study aimed to identify differences in LA and PV remodeling between HC and hypertensive heart disease (HHD) using 3-dimensional computed tomography. Included were 33 consecutive patients with HC, 25 with HHD, and 29 without any co-morbidities who were referred for catheter ablation of atrial fibrillation. Pre-ablation plasma atrial and brain natriuretic peptide levels, post-ablation troponin T level, and LA pressure were measured, and LA and PV diameters were determined 3 dimensionally. LA transverse diameter in the control group was smaller than that in the HHD or HC group (55 ± 6 vs 63 ± 9 vs 65 ± 12 mm, p = 0.0003). PV diameter in all 4 PVs was greatest in the HC group and second greatest in the HHD group (21.0 ± 3.1 vs 23.8 ± 2.8 vs 26.8 ± 4.1 mm, p <0.0001 for left superior PV). Differences in PV size between the HHD and HC groups were enhanced by indexing to the body surface area (12.4 ± 1.9 vs 13.1 ± 1.4 vs 16.1 ± 3.3 mm/m2, p <0.0001). The PV/LA diameter ratio was greater in the HC than in the other groups (0.38 ± 0.06 vs 0.38 ± 0.05 vs 0.42 ± 0.07, p = 0.01). Atrial natriuretic peptide, brain natriuretic peptide, troponin T levels, and LA pressure were highest in the HC group (all p <0.05). In conclusion, the stiff LA caused from atrial hypertrophy may account for higher levels of biomarkers, higher LA pressure, and PV-dominant remodeling in HC.
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5
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Firuzyar T, Jalilian AR, Aboudzadeh MR, Sadeghpour H, Shafiee-Ardestani M, Khalaj A. Preparation and preclinical evaluation of 68Ga-DOTA-amlodipine for L-type calcium channel imaging. Indian J Nucl Med 2016; 31:267-273. [PMID: 27833311 PMCID: PMC5041414 DOI: 10.4103/0972-3919.190797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Aim: In order to develop a possible tracer for L-type calcium channel imaging, we here report the development of a Ga-68 amlodipine derivative for possible PET imaging. Materials and Methods: Amlodipine DOTA conjugate was synthesized, characterized and went through calcium channel blockade, toxicity, apoptosis/necrosis tests. [68Ga] DOTA AMLO was prepared at optimized conditions followed by stability tests, partition coefficient determination and biodistribution studies using tissue counting and co incidence imaging up to 2 h. Results: [68Ga] DOTA AMLO was prepared at pH 4–5 in 7–10 min at 95°C in high radiochemical purity (>99%, radio thin layer chromatography; specific activity: 1.9–2.1 GBq/mmol) and was stable up to 4 h with a log P of −0.94. Calcium channel rich tissues including myocardium, and tissues with smooth muscle cells such as colon, intestine, and lungs demonstrated significant uptake. Co incidence images supported the biodistribution data up to 2 h. Conclusions: The complex can be a candidate for further positron emission tomography imaging for L type calcium channels.
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Affiliation(s)
- Tahereh Firuzyar
- Nuclear Medicine and Molecular Imaging Research Center, Shiraz University of Medical Science, Shiraz, Iran
| | - Amir Reza Jalilian
- Department of Medicinal Chemistry, Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
| | - Mohammad Reza Aboudzadeh
- Department of Medicinal Chemistry, Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
| | - Hossein Sadeghpour
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahdi Shafiee-Ardestani
- Nuclear Medicine and Molecular Imaging Research Center, Shiraz University of Medical Science, Shiraz, Iran
| | - Ali Khalaj
- Nuclear Medicine and Molecular Imaging Research Center, Shiraz University of Medical Science, Shiraz, Iran
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7
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Effect of Left Ventricular Outflow Tract Obstruction on Left Atrial Mechanics in Hypertrophic Cardiomyopathy. BIOMED RESEARCH INTERNATIONAL 2015; 2015:481245. [PMID: 26788503 PMCID: PMC4695661 DOI: 10.1155/2015/481245] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/19/2015] [Indexed: 12/31/2022]
Abstract
Left atrial (LA) volumes are known to be increased in hypertrophic cardiomyopathy (HCM) and are a predictor of adverse outcome. In addition, LA function is impaired and is presumed to be due to left ventricular (LV) diastolic dysfunction as a result of hypertrophy and myocardial fibrosis. In the current study, we assess the incremental effect of outflow tract obstruction (and concomitant mitral regurgitation) on LA function as assessed by LA strain. Patients with HCM (50 obstructive, 50 nonobstructive) were compared to 50 normal controls. A subset of obstructive patients who had undergone septal myectomy was also studied. Utilising feature-tracking software applied to cardiovascular magnetic resonance images, LA volumes and functional parameters were calculated. LA volumes were significantly elevated and LA ejection fraction and strain were significantly reduced in patients with HCM compared with controls and were significantly more affected in patients with obstruction. LA volumes and function were significantly improved after septal myectomy. LVOT obstruction and mitral regurgitation appear to further impair LA mechanics. Septal myectomy results in a significant reduction in LA volumes, paralleled by an improvement in function.
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8
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Olbrich HG, Michaelis H, Vandeplassche G, Borgers M, Oremek G, Krause E, Satter P, Kober G, Mutschler E, Kaltenbach M. Ultrastructural calcium distribution and myocardial calcium content in human idiopathic dilated cardiomyopathy. Cardiovasc Pathol 2015; 2:127-36. [PMID: 25990607 DOI: 10.1016/1054-8807(93)90024-v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/1992] [Accepted: 12/31/1992] [Indexed: 02/07/2023] Open
Abstract
Myocardial calcium overload in chronic heart failure is still a debatable issue. The aim of this study was to investigate the myocardial calcium content and intracellular calcium distribution in end-stage dilated cardiomyopathy. The explanted hearts of 13 patients (9 male, 4 female, mean age 49 ± 12 years) undergoing heart transplantation because of end-stage dilated cardiomyopathy were examined. Samples were obtained from the right and left ventricular free wall and from the septum. Calcium and magnesium content were measured by atomic absorption spectrophotometry. Ultrastructural calcium distribution was examined in dilated cardiomyopathy using the phosphate-pyroantimonate method. Ultrastructural calcium distribution was also examined in left ventricular biopsies obtained from 3 patients (male, mean age 47 ± 3.6 years) with nonfailing hearts. The number of mitochondrial calcium precipitates was estimated morphometrically by a point counting method. Myocardial calcium and magnesium content in dilated cardiomyopathy did not differ significantly among the right and left ventricles and septum ranging from 8.5 to 10.8 mmol/kg dry weight. The phosphate-pyroantimonate method visualized calcium precipitates being confined to the sarcolemma, T-tubules, intercalated disks, and mitochondria in both nonfailing myocardium and dilated cardiomyopathy. Because mitochondria may act as buffers of cytoplasmic calcium, mitochondrial calcium precipitates served as a criterion for a possible cellular calcium overload. No differences in the amount of mitochondrial calcium deposits were observed between dilated cardiomyopathy and nonfailing hearts. The data suggest that there is no global myocardial calcium overload in human eng-stage dilated cardiomyopathy.
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Affiliation(s)
- H G Olbrich
- Zentrum der Inneren Medizin, Universität Frankfurt, Germany
| | - H Michaelis
- Zentrum der Inneren Medizin, Universität Frankfurt, Germany
| | | | - M Borgers
- Zentrum der Chirurgie, Universität Frankfurt, Germany
| | - G Oremek
- Zentrum der Inneren Medizin, Universität Frankfurt, Germany
| | - E Krause
- Janssen Research Foundation, Beerse, Belgium
| | - P Satter
- Janssen Research Foundation, Beerse, Belgium
| | - G Kober
- Zentrum der Inneren Medizin, Universität Frankfurt, Germany
| | - E Mutschler
- Pharmakologisches Institut für Naturwissenschaftler, Universität Frankfurt, Germany
| | - M Kaltenbach
- Zentrum der Inneren Medizin, Universität Frankfurt, Germany
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9
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Development of an 111In-labeled dihydropyridine complex for L-type calcium channel imaging. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3656-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Yakar Tuluce S, Kayikcioglu M, Tuluce K, Yilmaz MG, Ozdogan O, Aydın M, Hasdemir C. Assessment of Left Atrial Appendage Function during Sinus Rhythm in Patients with Hypertrophic Cardiomyopathy: Transesophageal Echocardiography and Tissue Doppler Study. J Am Soc Echocardiogr 2010; 23:1207-16. [DOI: 10.1016/j.echo.2010.08.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Indexed: 11/29/2022]
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11
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Sun YG, Cao YX, Wang WW, Ma SF, Yao T, Zhu YC. Hydrogen sulphide is an inhibitor of L-type calcium channels and mechanical contraction in rat cardiomyocytes. Cardiovasc Res 2008; 79:632-41. [PMID: 18524810 DOI: 10.1093/cvr/cvn140] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
AIMS Hydrogen sulphide (H(2)S) is an endogenously generated gaseous transmitter that has recently been suggested to regulate cardiovascular functions. To date, there is no direct evidence for a potential role of H(2)S in regulating calcium channels in the heart. The present study aims to examine the hypothesis that H(2)S is a novel inhibitor of the L-type calcium channel current (I(Ca,L)). METHODS AND RESULTS Electrophysiological measurements were performed in cardiomyocytes isolated from Wistar-Kyoto and spontaneously hypertensive rats. Bath application of 100 microM NaHS (a H(2)S donor) significantly reduced the time required for the repolarization of the action potential. Inhibition of the peak I(Ca,L) by NaHS was determined to be concentration-dependent (25, 50, 100, 200, and 400 microM). NaHS inhibited the recovery from depolarization-induced inactivation. Electric field-induced [Ca(2+)]i transients and contraction of single cardiomyocytes and isolated papillary muscles were reduced by NaHS treatment. In contrast, caffeine induced an increase in [Ca(2+)]i that was not altered by NaHS. NaHS had no effect on the K(ATP) current or on the levels of cAMP and cGMP in the current study. CONCLUSION H(2)S is a novel inhibitor of L-type calcium channels in cardiomyocytes. Moreover, H(2)S-induced inhibition of [Ca(2+)]i appears to be a secondary effect owing to its initial action towards I(Ca,L). The inhibitory effect of H(2)S on I(Ca,L) requires further investigation, particularly in the exploration of new pathways involved in cardiac calcium homeostasis and disease pathology.
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Affiliation(s)
- Ying-Gang Sun
- Key Laboratory of Molecular Medicine, The Ministry of Education, Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, 138 Yi Xue Yuan Road, Shanghai 200032, P.R. China
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12
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Holschbach M, Roden W, Hamkens W. Synthesis of carbon-11 labelled calcium channel antagonists. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580290408] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Somura F, Izawa H, Iwase M, Takeichi Y, Ishiki R, Nishizawa T, Noda A, Nagata K, Yamada Y, Yokota M. Reduced myocardial sarcoplasmic reticulum Ca(2+)-ATPase mRNA expression and biphasic force-frequency relations in patients with hypertrophic cardiomyopathy. Circulation 2001; 104:658-63. [PMID: 11489771 DOI: 10.1161/hc3101.093869] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The relationship between left ventricular (LV) contractile functional reserve and gene expression of Ca(2+)-handling proteins in patients with hypertrophic cardiomyopathy (HCM) remains to be clarified. METHODS AND RESULTS We calculated the maximum first derivative of LV pressure (LV dP/dt(max)) and the LV pressure half-time (T(1/2)) during pacing in 14 patients with nonobstructive HCM (LV ejection fraction >55%) and 7 control subjects. Endomyocardial tissue was obtained, and mRNA levels of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2), ryanodine receptor-2, phospholamban, calsequestrin, and Na(+)/Ca(2+) exchanger were quantified by use of a real-time quantitative reverse transcription-polymerase chain reaction method. Group A consisted of 7 HCM patients who showed a progressive rise in the LV dP/dt(max) with increased heart rate. Group B consisted of 7 HCM patients in whom the heart rate-LV dP/dt(max) relation was biphasic at physiological pacing rates. Both the mean maximal wall thickness and the LV hypertrophy score in group B were greater than in group A (20+/-5 versus 15+/-3 mm and 7+/-1 versus 5+/-2 points, respectively). SERCA2 mRNA levels were significantly lower in group B (SERCA2/GAPDH ratio 0.34+/-0.15) compared with group A (0.72+/-0.27) and control subjects (0.85+/-0.47), whereas the mRNA expression of ryanodine receptor-2, phospholamban, calsequestrin, and Na(+)/Ca(2+) exchanger were similar in all groups. CONCLUSIONS These results suggest that downregulation of SERCA2 mRNA, resulting in altered Ca(2+) handling, may contribute to impaired LV contractile reserve in HCM patients with severe hypertrophy, even in the absence of detectable baseline systolic dysfunction.
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Affiliation(s)
- F Somura
- Cardiovascular Division, Department of Clinical Pathophysiology, the First Department of Internal Medicine, Nagoya University, Japan
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14
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Muth JN, Bodi I, Lewis W, Varadi G, Schwartz A. A Ca(2+)-dependent transgenic model of cardiac hypertrophy: A role for protein kinase Calpha. Circulation 2001; 103:140-7. [PMID: 11136699 DOI: 10.1161/01.cir.103.1.140] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Calcium imbalances have been implicated as an underlying mechanism of human cardiac dysfunction. The voltage-dependent calcium channel plays a critical role in calcium regulation in the heart. Thus, aberrant calcium signaling arising from this channel could initiate the calcium imbalances observed in heart failure. In the present study, we used a transgenic mouse with an increased number of L-type calcium channels to identify the role of an increased, sustained ingress of calcium as an initiator of hypertrophy. METHODS AND RESULTS Whole-heart histology and electrophysiology in isolated cardiomyocytes identified calcium-channel overexpression in the hearts of transgenic mice. Calcium-channel density was increased in 2-, 4-, and 8-month-old transgenic cardiomyocytes. Ventricular fibrosis, damage, and remodeling became more pronounced as the transgenic mice aged. Apoptosis was also present in transgenic hearts at 8 months of age. Increased protein kinase Calpha activation was elevated before the development of hypertrophy and failure. CONCLUSIONS Transgenic mice developed hypertrophy and severe cardiomyopathy as a function of age, thus confirming that changes in channel density are sufficient to induce disease. The small, sustained increase in the ingress of Ca(2+) through the calcium channel elevated protein kinase Calpha before the development of hypertrophy, suggesting that protein kinase Calpha plays an important role in triggering hypertrophy.
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Affiliation(s)
- J N Muth
- Institute of Molecular Pharmacology and Biophysics, Department of Cell Biology, Neurobiology, and Anatomy, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0828, USA
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15
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Walker CA, Crawford FA, Spinale FG. Myocyte contractile dysfunction with hypertrophy and failure: relevance to cardiac surgery. J Thorac Cardiovasc Surg 2000; 119:388-400. [PMID: 10649220 DOI: 10.1016/s0022-5223(00)70199-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- C A Walker
- Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, SC 29425, USA
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16
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Morgan PE, Aiello EA, Chiappe de Cingolani GE, Mattiazzi AR, Cingolani HE. Chronic administration of nifedipine induces up-regulation of functional calcium channels in rat myocardium. J Mol Cell Cardiol 1999; 31:1873-83. [PMID: 10525425 DOI: 10.1006/jmcc.1999.1019] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies from our laboratory demonstrated the up-regulation of cardiac dihydropyridine (DHP) receptors in rabbits chronically treated with nifedipine (NIFE). The goal of the present study was to further examine the functionality of this increased number of receptors by analysing different steps of excitation contraction coupling mechanism in adult rats chronically treated with NIFE (a single 10-mg oral dose/kg/day for 28 days). Ca2+ channel density was assessed by specific binding at the DHP receptors with [methyl-(3)H]PN 200-110 in rat ventricular membranes. Chronic NIFE treatment produced up-regulation of Ca2+ channels, being the maximal binding capacities 222+/-19 fmol/mg protein (n=14) and 310+/-21 fmol/mg protein (n=11) in untreated and treated animals, respectively (P<0.05). The functional consequences of this up-regulation of Ca2+ channels were determined in isolated ventricular myocytes by measuring L-type Ca2+ currents (I(Ca)) with the whole-cell configuration of patch-clamp technique and by intracellular Ca2+ (Ca2+(i)) transients estimated by the Indo-1/AM fluorescence ratio (410/482) simultaneously monitored with cell shortening. Peak I(Ca) density recorded at 0 mV was 32% greater in myocytes isolated from the treated group than in those obtained from the untreated group (-10.43+/-0.73 pA/pF (n=13) vs-7.10+/-0.59 pA/pF (n=12) P<0.05). Ca2+(i) transient amplitude and cell shortening, explored at 1 and 2 mM extracellular calcium ([Ca]0) were significantly higher in ventricular myocytes obtained fom NIFE-treated rats than in myocytes isolated from untreated animals. At 2 mM [Ca]0, the values of Ca2+(i) transient and shortening were 460+/-61 nM and 11+/-1 % of resting length (L(0)) in myocytes from treated rats (n=9) and 212+/-22 nM and 5.3+/-0.5% of L(0) in myocytes from control rats (n=6, P<0.05). The results demonstrate an up-regulation of functionally-active cardiac Ca2+ channels after NIFE treatment, and offer a possible explanation for a "withdrawal effect" at myocardial level after the suppression of the treatment with this drug.
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Affiliation(s)
- P E Morgan
- Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, 1900, Argentina
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17
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Abstract
"Remodeling" implies changes that result in rearrangement of normally existing structures. This review focuses only on permanent modifications in relation to clinical dysfunction in cardiac remodeling (CR) secondary to myocardial infarction (MI) and/or arterial hypertension and includes a special section on the senescent heart, since CR is mainly a disease of the elderly. From a biological point of view, CR is determined by 1 ) the general process of adaptation which allows both the myocyte and the collagen network to adapt to new working conditions; 2) ventricular fibrosis, i.e., increased collagen concentration, which is multifactorial and caused by senescence, ischemia, various hormones, and/or inflammatory processes; 3) cell death, a parameter linked to fibrosis, which is usually due to necrosis and apoptosis and occurs in nearly all models of CR. The process of adaptation is associated with various changes in genetic expression, including a general activation that causes hypertrophy, isogenic shifts which result in the appearance of a slow isomyosin, and a new Na+-K+-ATPase with a low affinity for sodium, reactivation of genes encoding for atrial natriuretic factor and the renin-angiotensin system, and a diminished concentration of sarcoplasmic reticulum Ca2+-ATPase, beta-adrenergic receptors, and the potassium channel responsible for transient outward current. From a clinical point of view, fibrosis is for the moment a major marker for cardiac failure and a crucial determinant of myocardial heterogeneity, increasing diastolic stiffness, and the propensity for reentry arrhythmias. In addition, systolic dysfunction is facilitated by slowing of the calcium transient and the downregulation of the entire adrenergic system. Modifications of intracellular calcium movements are the main determinants of the triggered activity and automaticity that cause arrhythmias and alterations in relaxation.
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Affiliation(s)
- B Swynghedauw
- Institut National de la Sante et de la Recherche Medicale U. 127, Hopital Lariboisiere, Paris, France
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18
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Jung WI, Sieverding L, Breuer J, Hoess T, Widmaier S, Schmidt O, Bunse M, van Erckelens F, Apitz J, Lutz O, Dietze GJ. 31P NMR spectroscopy detects metabolic abnormalities in asymptomatic patients with hypertrophic cardiomyopathy. Circulation 1998; 97:2536-42. [PMID: 9657474 DOI: 10.1161/01.cir.97.25.2536] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) often causes sudden, unexpected death in adolescents and young adults. Alterations in myocardial metabolism are considered to be causes for contractile dysfunction. We examined the question of whether metabolic abnormalities antedate the manifestation of symptoms in patients with HCM. METHODS AND RESULTS Proton-decoupled 31P NMR spectroscopy of the anterior left ventricular wall of the heart of 14 young, asymptomatic patients with HCM was performed with a 1.5-T whole-body imager. Spectra of the phosphate metabolites were compared with those of normal control subjects. The patients exhibited a significantly reduced (P<0.02) ratio of phosphocreatine (PCr) to ATP of 1.98+/-0.37 (mean+/-SD), compared with 2.46+/-0.53 obtained in 11 normal control subjects. In addition, the group of patients with severe hypertrophy of the interventricular septum (n=8) showed a significantly increased (P<0.05) Pi-to-PCr ratio, with a Pi x 100/PCr of 20.0+/-8.3 versus 9.7+/-7.2 in control subjects. Both abnormalities are similar to those found in ischemic myocardium. This view is also supported by a significantly increased (P<0.01) phosphomonoester (PME)-to-PCr ratio, with a PME x 100/PCr of 20.7+/-11.2 compared with 8.4+/-6.7 in control subjects, indicating altered glucose metabolism. CONCLUSIONS 31P NMR spectroscopy detects alterations of myocardial metabolism in asymptomatic patients with HCM. These alterations may contribute to the understanding of the pathophysiology and natural history of the disease.
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Affiliation(s)
- W I Jung
- Hypertension and Diabetes Research Unit, Max Grundig Clinic, Bühl, Germany
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19
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Yashar PR, Fransua M, Frishman WH. The sodium-calcium ion membrane exchanger: physiologic significance and pharmacologic implications. J Clin Pharmacol 1998; 38:393-401. [PMID: 9602949 DOI: 10.1002/j.1552-4604.1998.tb04442.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The Na(+)-Ca2+ exchanger is a non-ATP-dependent protein that, under steady-state conditions, extrudes Ca2+ from the interior of the cell into the extracellular space via facilitated transport. The activity of the exchanger seems to be reduced in myocardial ischemia, leading to increased intracellular Ca2+ in the ischemic heart, which can result in arrhythmia, myocardial stunning, and necrosis. In contrast, congestive heart failure and myocardial hypertrophy are associated with increased exchanger activity and a decreased inotropic state. Pharmacologic agents are being developed to modulate sodium ion levels in the cell, which could enhance or reduce sodium-calcium exchange as needed in various pathophysiologic states. At this time there are no available drugs that act specifically on the Na(+)-Ca2+ exchanger itself. The exchanger has been cloned, and inhibitory peptides of the exchanger may soon be available for possible use in treatment of congestive heart failure.
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Affiliation(s)
- P R Yashar
- Department of Medicine, Cedars-Sinai Medical Center, UCLA School of Medicine, USA
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20
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Izawa H, Yokota M, Takeichi Y, Inagaki M, Nagata K, Iwase M, Sobue T. Adrenergic control of the force-frequency and relaxation-frequency relations in patients with hypertrophic cardiomyopathy. Circulation 1997; 96:2959-68. [PMID: 9386163 DOI: 10.1161/01.cir.96.9.2959] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Exercise-induced enhancement of the force-frequency and relaxation-frequency relations has been studied in conscious animals but not in intact diseased human hearts. METHODS AND RESULTS We evaluated left ventricular (LV) isovolumic contraction (dP/dt(max)) and relaxation (tau) during atrial pacing and dynamic exercise in 13 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 7 control subjects to investigate the influence of exercise on the force-frequency and relaxation-frequency relations. Group A consisted of 6 patients in whom the heart rate (HR)-dP/dt(max) relation was markedly enhanced during exercise (88+/-30%) compared with during pacing (34+/-15%). Group B consisted of 7 patients in whom the HR-dP/dt(max) relation showed similar enhancement during exercise (28+/-7%) and atrial pacing (28+/-11%). There was no difference in the HR-tau (derivative method [TD] and pressure half-time method [T(1/2)]) relation between pacing and exercise in groups A and B. Both the mean maximal wall thickness and the hypertrophy score in group B were greater than in group A (27+/-5 versus 19+/-2 mm and 7+/-1 versus 5+/-1 points, respectively; both P<.01). There was no difference in the LV peak systolic pressure, end-diastolic pressure, or the plasma level of catecholamines at baseline, at 50 W of exercise, and at peak pacing between groups A and B. The HR-dP/dt(max) relation in the control group was markedly enhanced during exercise (80+/-27%) compared with during pacing (32+/-14%). The HR-tau relation in the control group was enhanced during exercise (TD, 35+/-9%; T(1/2), 34+/-8%) compared with during pacing (TD, 12+/-7%; T(1/2), 14+/-7%). CONCLUSIONS Exercise-induced enhancement of the relaxation-frequency relation was inhibited in all HCM patients, regardless of the degree of LV hypertrophy. The patients without exercise-induced enhancement of the force-frequency relation had more severe LV hypertrophy than the patients with the enhancement, indicating that the adrenergic control of the force-frequency relation may, at least in part, depend on the severity of LV hypertrophy or the stage of HCM.
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Affiliation(s)
- H Izawa
- First Department of Internal Medicine, Nagoya University School of Medicine, Japan
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21
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Li RK, Li G, Mickle DA, Weisel RD, Merante F, Luss H, Rao V, Christakis GT, Williams WG. Overexpression of transforming growth factor-beta1 and insulin-like growth factor-I in patients with idiopathic hypertrophic cardiomyopathy. Circulation 1997; 96:874-81. [PMID: 9264495 DOI: 10.1161/01.cir.96.3.874] [Citation(s) in RCA: 153] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Idiopathic hypertrophic cardiomyopathy (HCM) is characterized by regional myocardial hypertrophy. To investigate involvement of growth factors on myocardial hypertrophy in HCM patients, we evaluated gene expression and cellular localization of transforming growth factor-beta1 (TGF-beta1), insulin-like growth factors (IGF-I and IGF-II), and platelet-derived growth factor-B (PDGF-B) in ventricular biopsies obtained from patients with HCM (n=8), aortic stenosis (AS) (n=8), or stable angina (SA) (n=8) and from explanted hearts with ischemic cardiomyopathy (TM) (n=7). METHODS AND RESULTS Levels of TGF-beta1, IGF-I, IGF-II, and PDGF-B transcripts were quantified with the use of multiplex RT-PCR. Glyceraldehyde 3-phosphate dehydrogenase was used as an internal standard. Antibodies against TGF-beta and IGF-I were used to localize their peptides within the myocardium. Antisense and sense (control) cRNA probes of TGF-beta1 and IGF-I, labeled with digoxigenin, were used to localize the growth factor transcripts by in situ hybridization. mRNA levels (densitometric ratio of growth factor/glyceraldehyde-3-phosphate dehydrogenase) of TGF-beta1 and IGF-I in HCM (0.75+/-0.05 and 0.85+/-0.15, respectively; mean+/-1 SEM) were significantly (P<.01 for all groups) elevated in comparison with non-HCM myocardium (AS: 0.38+/-0.07, 0.29+/-0.06; SA: 0.32+/-0.04, 0.18+/-0.05; TM: 0.25+/-0.03, 0.15+/-0.03). mRNA levels of TGF-beta1 and IGF-I in the hypertrophic AS myocardium were greater (P=.02, P=.05) than those in the explanted myocardium (TM). Immunohistochemical and in situ hybridization studies showed increased expression of TGF-beta1 and IGF-I in the HCM cardiomyocytes. CONCLUSIONS Gene expression of TGF-beta1 and IGF-I was enhanced in idiopathic hypertrophic cardiomyopathy and may be associated with its development.
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Affiliation(s)
- R K Li
- Department of Clinical Biochemistry, and The Centre for Cardiovascular Research, The Toronto Hospital-General Division, University of Toronto, Ontario, Canada.
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22
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Krasnow N. Subaortic septal bulge simulates hypertrophic cardiomyopathy by angulation of the septum with age, independent of focal hypertrophy. An echocardiographic study. J Am Soc Echocardiogr 1997; 10:545-55. [PMID: 9203495 DOI: 10.1016/s0894-7317(97)70009-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Focal hypertrophy of the basal anterior septum occurs not infrequently in elderly patients and is considered by some to be a significant form of hypertrophic cardiomyopathy; others consider it to be an unimportant anatomic variant associated with an angulated septum, called a septal bulge (SB). We analyzed 94 cases of SB collected prospectively and compared them with 88 patients with extensive hypertrophic cardiomyopathy (HCM), 20 patients with hypertrophic cardiomyopathy limited to the entire septum (ASH), and 20 age-matched controls. The SB cases were also divided into three groups, with marked, moderate, or no basal septal hypertrophy associated with the occurrence of an SB. All groups of SB patients had increased fractional shortening compared with controls (0.48 +/- 0.07 versus controls 0.40 +/- 0.07), comparable with HCM (0.48 +/- 0.12), and increased left ventricular outflow tract velocity both at rest and especially after amyl nitrite inhalation (3.42 +/- 1.35 versus 1.55 +/- 0.60 m/sec [controls]). Other features of HCM were not present: normal wall thickness except for the basal septal hypertrophy, no anterior malposition in SB patients, no age-independent reversal of ratio of early to late mitral inflow velocity (E/A), and no decrease in end-diastolic dimension. It is concluded that outflow tract narrowing by an angulated septum is the primary mechanism responsible for the increased outflow tract velocity, rather than the hypertrophic septum. The resultant increase in convective acceleration simulates the dynamics of hypertrophic cardiomyopathy. The focal hypertrophy may be secondary and contributory to the enhanced ventricular dynamics, but it does not appear to be a primary cardiomyopathy.
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Affiliation(s)
- N Krasnow
- Division of Cardiology, State University of New York Health Sciences Center at Brooklyn, USA
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23
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Ohya Y, Abe I, Fujii K, Kobayashi K, Onaka U, Fujishima M. Intima-media thickness of the carotid artery in hypertensive subjects and hypertrophic cardiomyopathy patients. Hypertension 1997; 29:361-5. [PMID: 9039128 DOI: 10.1161/01.hyp.29.1.361] [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: 02/03/2023]
Abstract
While hypertension is known to cause left ventricular and vascular hypertrophy, the relationship between alterations of vascular and cardiac structures in patients with hypertrophic cardiomyopathy has not been fully clarified. We measured intima-media thickness of carotid arteries by ultrasonography in patients with hypertrophic cardiomyopathy (n = 16), normotensive subjects (n = 358), and hypertensive subjects (n = 386) in a cohort of 7940 male employees of a bus company. Our object was to determine whether vascular alteration occurs in hypertrophic cardiomyopathy similarly as in hypertension. Hypertrophic cardiomyopathy (wall thickness > or = 15 mm; asymmetrical hypertrophy without hypertension) was screened with family history and electrocardiography followed by echocardiography. The intima-media thickness in patients with hypertrophic cardiomyopathy (mean, 0.61 mm) did not differ from that of normotensive subjects (0.60 mm) but was significantly less than that of hypertensive subjects with left ventricular hypertrophy (wall thickness > or = 14 mm; n = 22; 0.73 mm). In a scatterplot of intima-media thickness versus interventricular septal thickness, these two parameters were significantly correlated in normotensives and hypertensives. The patients with hypertrophic cardiomyopathy distributed outside the 95% confidence range of the normotensive and hypertensive subjects. In summary, the increase in intima-media thickness of the carotid artery paralleled left ventricular hypertrophy in normotensive and hypertensive subjects. Patients with hypertrophic cardiomyopathy had a normal intima-media thickness regardless of the hypertrophied left ventricle. Thus, information on intima-media thickness may be useful in differentiating hypertensive left ventricular hypertrophy from hypertrophic cardiomyopathy.
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Affiliation(s)
- Y Ohya
- Second Department of Internal Medicine, Kyushu University, Faculty of Medicine, Fukuoka, Japan.
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24
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Izawa H, Yokota M, Nagata K, Iwase M, Sobue T. Impaired response of left ventricular relaxation to exercise-induced adrenergic stimulation in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol 1996; 28:1738-45. [PMID: 8962560 DOI: 10.1016/s0735-1097(96)00378-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES We investigated the effect of adrenergic stimulation on left ventricular relaxation in patients with hypertrophic cardiomyopathy. BACKGROUND Exercise-induced decreases in acceleration of left ventricular relaxation have been observed in patients with hypertrophic cardiomyopathy. However, data on sequential changes in left ventricular relaxation during exercise are limited. METHODS We measured right (fluid filled) and left (high fidelity micromanometer) ventricular pressures during moderate supine ergometer exercise and during rapid right atrial pacing in four groups of patients: 9 with severe hypertrophic cardiomyopathy, 9 with moderate hypertrophic cardiomyopathy, 10 with hypertension and moderate hypertrophy and 5 control subjects. RESULTS There was a curvilinear relation between the time constant of relaxation (tau) and heart rate in all groups during exercise. There was no difference in the slope of this relation between the two hypertrophic cardiomyopathy subgroups. Although the slope of this relation between tau and heart rate was steeper in the hypertensive than the moderate hypertrophic cardiomyopathy group (p < 0.001, analysis of covariance), the decrease in tau during right atrial pacing was similar in both groups. There were no significant differences in plasma levels of catecholamines at rest or at peak exercise among groups or in maximal heart rate during pacing. CONCLUSIONS Pacing-induced changes in tau in hypertrophic cardiomyopathy were similar to those in hypertensive hypertrophy, but remarkable decrease in exercise-induced acceleration of tau were observed only in hypertrophic cardiomyopathy. Our results may indicate a depressed left ventricular relaxation response to exercise-induced adrenergic stimulation in hypertrophic cardiomyopathy.
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Affiliation(s)
- H Izawa
- First Department of Internal Medicine and Department of Clinical Laboratory Medicine, Nagoya University School of Medicine, Japan
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25
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Flesch M, Schwinger RH, Schiffer F, Frank K, Südkamp M, Kuhn-Regnier F, Arnold G, Böhm M. Evidence for functional relevance of an enhanced expression of the Na(+)-Ca2+ exchanger in failing human myocardium. Circulation 1996; 94:992-1002. [PMID: 8790037 DOI: 10.1161/01.cir.94.5.992] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The present study aimed at investigating the expression of the Na(+)-Ca2+ exchanger and its functional role in human failing myocardium. METHODS AND RESULTS Na(+)-Ca2+ exchanger mRNA and protein levels were examined in nonfailing (NF, n = 8) and failing human myocardium (New York Heart Association functional class IV) with idiopathic dilated cardiomyopathy (DCM, n = 8) or ischemic heart disease (ICM, n = 6). The inotropic effect of the Na+ channel activator BDF 9148 was determined in electrically driven left ventricular papillary muscle strip preparations (1 Hz, 37 degrees C) from nonfailing (n = 8) and failing (n = 8) human hearts. Na(+)-Ca2+ exchanger mRNA levels were significantly increased, by 79% (P < .001) in DCM and by 58% (P < .01) in ICM compared with NF; protein levels increased by 36% (P < .001) and by 20% (P < .05), respectively. BDF 9148 increased the force of contraction concentration dependently, with a similar maximal effect in NYHA class IV and NF, but was more potent in NYHA class IV as demonstrated by a significantly smaller (P < .01) EC50 value (NYHA class IV, 0.18 [0.16 to 0.22] mumol/L; NF, 1.65 [1.3 to 3.0] mumol/L). In NYHA class IV, BDF 9148 (0.1 mumol/L) restored the positive force-frequency relationship and reduced the frequency-dependent increase in diastolic tension in relation to force of contraction. CONCLUSIONS The increased expression of the Na(+)-Ca2+ exchanger is a possible explanation for the increased inotropic potency of the Na+ channel activator BDF 9148 in failing human myocardium. The increase in exchanger molecules could be of functional relevance for the modulation of cardiac contractility by agents that increase the intracellular Na+ concentration. Enhancement of Na(+)-Ca2+ exchanger activity might be a powerful mechanism for increasing cardiac contractility in chronic heart failure.
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Affiliation(s)
- M Flesch
- Klinik III für Innere Medizin Universität zu Köln, FRG
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26
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Gengo PJ. Physiologic and emerging pathophysiologic role of cardiac calcium channels. Heart Fail Rev 1996. [DOI: 10.1007/bf00126379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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27
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DAUBERT JCLAUDE, PAVIN DOMINIQUE, GRAS DANIEL, PLACE CHRISTIANDE, LECLERCQ CHRISTOPHE, LE BRETON HERVÉ, MABO PHILIPPE. Importance of Atrial Contraction in Hypertrophic Obstructive Cardiomyopathy: Implications for Pacing Therapy. J Interv Cardiol 1996. [DOI: 10.1111/j.1540-8183.1996.tb00639.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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28
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Schwinger RH, Müller-Ehmsen J, Frank K, Koch A, Erdmann E. Enhanced sensitivity of the failing human myocardium to cardiac glycosides and Na(+)-channel activators. Am Heart J 1996; 131:988-93. [PMID: 8615321 DOI: 10.1016/s0002-8703(96)90184-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cardiac glycosides and Na+ -channel activators increase intracellular Na+ and thereby enhance the transport rate of the sarcolemmal Na+/Ca2+ exchanger. We tested the hypothesis of whether increased expression of the Na+/Ca2+ exchanger in failing human myocardium is accompanied by enhanced sensitivity of the failing human myocardium toward cardiac glycosides and Na+ -channel activators. We studied the positive inotropic effects of the new Na+ -channel activator BDF and the cardiac glycoside ouabain in human failing (New York Heart Association [NYHA] functional class IV, heart transplants for dilated cardiomyopathy, n = 11) and nonfailing (donor hearts, n = 5) myocardium on electrically driven left ventricular papillary muscle strips (1 Hz, 37 degrees C). The effectiveness of ouabain and BDF to increase force of contraction was similar in human nonfailing and failing myocardium. BDF was more potent to increase force of contraction in failing than in nonfailing tissue (p < 0.05). The time until maximal inotropic effect developed after ouabain was significantly shorter in NYHA IV (mean 150 +/- 16 min) than in nonfailing myocardium (mean 240 +/- 20 min). These results suggest that human failing myocardium exerts and enhanced sensitivity to cardiac glycosides and Na+ -channel activators, possibly because of enhanced expression of the Na+/Ca2+ exchanger or because of an altered intracellular Na+ -homeostasis.
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Affiliation(s)
- R H Schwinger
- Medizinische Klinik III, Universitat zu Köln, Germany
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29
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Haase H, Kresse A, Hohaus A, Schulte HD, Maier M, Osterziel KJ, Lange PE, Morano I. Expression of calcium channel subunits in the normal and diseased human myocardium. J Mol Med (Berl) 1996; 74:99-104. [PMID: 8820405 DOI: 10.1007/bf00196785] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We investigated the expression of alpha1 and beta subunits of the L-type Ca2+ channel on the protein level in cardiac preparations from normal human heart ventricles and from the hypertrophied septum of patients with hypertrophic obstructive cardiomyopathy (HOCM). 1,4-Dihydropyridine (DHP) binding and immunorecognition by polyclonal antibodies directed against the C-terminal amino acid sequences of the beta2 and beta3 subunits were used for detection and quantification of alpha1, beta2, and beta3 subunits. Bmax of high-affinity DHP binding was 35 +/- 2 fmol/mg protein in HOCM and 20 +/- 2 fmol/mg protein in normal human hearts (P<0.05). In rabbit hearts the anti-beta2 subunit antibody immunoprecipitated 80% of the total amount of DHP-labeled Ca2+ channels present in the assay. Under identical experimental conditions 25% of labeled Ca2+ channels were recovered in the immunoprecipitates of both normal and HOCM ventricles. A similar partial immunoprecipitation was observed in pig hearts. Immunoblot analysis demonstrated that the beta2 subunit was associated with the DHP receptor/Ca2+ channel in cardiac muscle of rabbit, pig, and human heart. In neither of these purified cardiac Ca2+ channels was the beta3 subunit isoform detected. Our results suggest that both alpha1 and beta2 subunit expression is upregulated in HOCM in a coordinate manner.
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Affiliation(s)
- H Haase
- Max-Delbruck Center for Molecular Medicine, Berlin, Germany
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30
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Abstract
Calcium antagonists continue to be used to treat congestive heart failure (CHF), despite clinical evidence that they may exacerbate the disease. The systemic vasodilatory actions of these drugs make them potentially attractive for use as afterload reducing agents in patients with CHF. Newer calcium antagonists of the 1,4-dihydropyridine class, with claims of little or no negative inotropic properties and minimal effects on the sympathetic nervous system, seem a promising treatment of this disease. All calcium antagonists, however, consistent with their ability to block transmembrane calcium transport in cardiac muscle cells, are intrinsically negative inotropes. Moreover, clinical trial data are inconclusive about the ability of these newer calcium antagonists to activate the sympathetic nervous system. The relatively small numbers of patients with CHF, the differing degrees of CHF in different patient groups, and the variation in route of administration, dosage, and schedule of hemodynamic measurements make analyses of published data difficult. Although some patients with CHF respond positively to treatment with calcium antagonists, there is great individual variability of response, and the majority of patients show deterioration of myocardial function when taking calcium antagonists. Until conclusive clinical evidence of the safety and effectiveness of calcium antagonists in the treatment CHF is available, they should not be used to treat this disease unless individual patient characteristics clearly indicate a positive benefit/risk ratio.
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Affiliation(s)
- R W Piepho
- School of Pharmacy, University of Missouri-Kansas City 64110-2499, USA
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31
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Brodde OE, Adamczyk M, Busch F, Bossaller C, Duske E, Fleck E, Götze S, Auch-Schwelk W. Selective downregulation of rat cardiac beta 1-adrenoceptors by cyclosporine A: prevention by diltiazem or angiotensin-converting enzyme inhibitors. J Am Coll Cardiol 1995; 25:761-7. [PMID: 7860926 DOI: 10.1016/0735-1097(94)00425-p] [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: 01/27/2023]
Abstract
OBJECTIVES This study attempted to determine whether long-term treatment with cyclosporine A in rats affects cardiac beta 1-adrenoceptors and whether this can be prevented by angiotensin-converting enzyme inhibitors or calcium-entry blocking agents. BACKGROUND In the transplanted human heart the density of beta 1-adrenoceptors decreases with time after transplantation, whereas that of beta 2-adrenoceptors does not. Because heart transplant recipients are treated with cyclosporine A, we studied whether administration of cyclosporine A in rats might cause this beta 1-adrenoceptor downregulation. METHODS We performed two studies. First, we treated groups of 10 male normotensive Wistar rats orally with 30 mg/kg body weight per day of cyclosporine A, 10 mg/kg per day of enalapril and 60 mg/kg per day of diltiazem, alone or in combination, for 6 weeks each. Second, we treated groups of 15 male normotensive Wistar rats orally with 15 mg/kg per day of cyclosporine A and 10 mg/kg per day of lisinopril, alone or in combination, for 6 weeks each. At the end of each treatment regimen, cardiac beta-adrenoceptor density and subtype distribution were assessed by (-)-[125I]iodocyanopindolol binding. RESULTS Both doses of cyclosporine A caused a significant decrease in cardiac beta 1-adrenoceptor density without affecting beta 2-adrenoceptor density. Although diltiazem and the angiotensin-converting enzyme inhibitors alone did not affect cardiac beta-adrenoceptors, they prevented the cyclosporine A-induced downregulation of beta 1-adrenoceptors. CONCLUSIONS In normotensive Wistar rats, cyclosporine A causes a significant decrease in cardiac beta 1-adrenoceptors without affecting beta 2-adrenoceptors. This can be prevented by diltiazem or angiotensin-converting enzyme inhibitors. In heart transplant recipients, who undergo long-term treatment with cyclosporine A, there is a very similar beta 1-adrenoceptor down-regulation with time after transplantation. Thus, administration of cyclosporine A may cause these beta-adrenoceptor subtype alterations.
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Affiliation(s)
- O E Brodde
- Department of Internal Medicine, University of Essen, Germany
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Vatner DE, Sato N, Kiuchi K, Shannon RP, Vatner SF. Decrease in myocardial ryanodine receptors and altered excitation-contraction coupling early in the development of heart failure. Circulation 1994; 90:1423-30. [PMID: 7522133 DOI: 10.1161/01.cir.90.3.1423] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Rapid ventricular pacing for 1 day reduced myocardial contractile function without inducing heart failure in conscious, chronically instrumented dogs. After 4 to 7 weeks of pacing, myocardial contractility was depressed further and overt signs of congestive heart failure, eg, ascites, dyspnea, and edema, were evident. METHODS AND RESULTS The mechanical restitution response, a physiological index of calcium release, was depressed at 1 day of rapid ventricular pacing. Postextrasystolic potentiation was also depressed by a similar amount, 14 +/- 3%, at 1 day after pacing. The response to isoproterenol 0.2 microgram/kg per minute was depressed by a significantly greater amount (P < .05), 52 +/- 7%, at 1 day after pacing. 3H-ryanodine receptor binding fell from 1013 +/- 25 to 808 +/- 42 fmol/mg after 1 day of pacing and remained depressed at similar levels (782 +/- 61 fmol/mg) at 4 to 7 weeks when heart failure was manifest. Ryanodine receptor affinity was unchanged from control values. Neither dihydropyridine binding nor affinity for 3H-PN200-110 was changed from control levels. Within 5 days after recovery from 1 day of pacing, physiological responses to isoproterenol, postextrasystolic potentiation, and mechanical restitution recovered, as did 3H-ryanodine binding density. CONCLUSIONS These findings suggest that the changes in excitation-contraction coupling and potentially the sarcoplasmic reticulum calcium release channel occur early in the development of heart failure and therefore may be important in the pathogenesis of the contractile abnormalities in this disease state.
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Affiliation(s)
- D E Vatner
- Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, Mass
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Bingisser R, Candinas R, Schneider J, Hess OM. Risk factors for systolic dysfunction and ventricular dilatation in hypertrophic cardiomyopathy. Int J Cardiol 1994; 44:225-33. [PMID: 8077068 DOI: 10.1016/0167-5273(94)90286-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The history of an 18-year-old male with hypertrophic cardiomyopathy (HCM) and ventricular dilatation is presented and the literature on systolic dysfunction and ventricular dilatation in patients with HCM is statistically analyzed in search of risk factors. The patient was followed for 7 years when he developed recurrent ventricular fibrillation, left ventricular dilatation and low cardiac output. An automatic cardioverter-defibrillator was implanted but the patient died of electro-mechanical dissociation. In order to define risk factors for systolic dysfunction and ventricular dilatation in HCM, the literature data of 17 patients with this complication were compared to a group of 139 consecutive patients with HCM from our hospital. The risk factors identified were a more markedly increased septal (20.1 vs. 18.0 mm, P < 0.05) and posterior wall thickness (13.6 vs. 11.0 mm, P < 0.001) in the patients subsequently developing systolic dysfunction and ventricular dilatation, whereas age, sex and the ratio between septal and posterior wall thickness were not significantly different between the two groups. A severely increased ventricular mass appears to be a risk factor for the development of systolic dysfunction with ventricular dilatation in HCM. Prognosis is usually poor and the reported case showed fatal ventricular arrhythmia despite the implantation of an automatic cardioverter-defibrillator.
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Affiliation(s)
- R Bingisser
- Department of Internal Medicine, University Hospital, Zurich, Switzerland
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Abstract
Calcium antagonists comprise a diverse group of chemically unrelated agents that interact with voltage-operated calcium channels (L-type) and thereby inhibit smooth muscle and cardiac contractility. Although they interact with the alpha 1 subunit of voltage-operated calcium channels, all calcium antagonists are not identical pharmacological agents. They are not only different from a chemical point of view, but also because some of them exhibit tissue selectivity, being more powerful blockers of the contraction of arteries than of cardiac muscle. The current view that their major therapeutic action is related to vasodilation is an oversimplification, as their action is more complex and may be related to factors other than hemodynamic ones.
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Affiliation(s)
- T Godfraind
- Laboratoire de Pharmacologie, Université Catholique de Louvain, Bruxelles, Belgium
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Arai M, Matsui H, Periasamy M. Sarcoplasmic reticulum gene expression in cardiac hypertrophy and heart failure. Circ Res 1994; 74:555-64. [PMID: 8137493 DOI: 10.1161/01.res.74.4.555] [Citation(s) in RCA: 245] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M Arai
- Molecular Cardiology Laboratory, University of Cincinnati College of Medicine, Ohio
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Galinier M, Sénard JM, Valet P, Arias A, Daviaud D, Glock Y, Bounhoure JP, Montastruc JL. Cardiac beta-adrenoceptors and adenylyl cyclase activity in human left ventricular hypertrophy due to pressure overload. Fundam Clin Pharmacol 1994; 8:90-9. [PMID: 8181801 DOI: 10.1111/j.1472-8206.1994.tb00784.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of left ventricular hypertrophy (LVH) due to chronic pressure overload on right atrial (RA) and left ventricular (LV) myocardial beta-adrenergic receptor (beta-AR) density and subtypes, adenylyl cyclase (AC) activity and ADP-pertussis toxin ribosylated proteins was investigated in humans with LVH due to aortic stenosis and in patients without LVH undergoing heart surgery for mitral stenosis or coronary artery disease taken as controls. Both groups presented normal systolic function or plasma catecholamine levels. In LVH and controls, beta-AR density was similar in RA (62 +/- 6 vs 77 +/- 12 fmol.mg-1 protein) and LV (39 +/- 7 vs 32 +/- 2 fmol.mg-1 protein). In LVH, beta 1-AR percentage was < than in controls in LV (35 +/- 11 vs 73 +/- 5%, P < 0.05) but not in RA (79 +/- 5 vs 73 +/- 8%). Basal AC activity in RA (19 +/- 4 vs 21 +/- 6 pmol.mg-1 protein) and LV (22 +/- 5 vs 27 +/- 3 pmol.mg-1 protein) was similar in LVH and in controls. Isoprenaline-induced stimulation of AC in RA was similar in LVH and in controls (51 +/- 18 vs 36 +/- 18%) but < in LV of LVH (7 +/- 6 vs 45 +/- 6%, P < 0.05). In the presence of ICI-118,551 (a beta 2-adrenoceptor antagonist), isoprenaline failed to induce any increase in cAMP in LVH. The quantification of ADP-pertussis toxin ribosylated proteins indicated a lower concentration of substrates in LV myocardial membranes from LVH. These data indicate that in LVH due to pressure overload, there is a down-regulation of beta 1-AR and an increase in beta 2-AR density. This is associated with alterations of the transmembrane signalling marked by a decreased capacity of isoprenaline to stimulate AC and an impaired expression of Gi proteins.
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Affiliation(s)
- M Galinier
- Service de Cardiologie et de Chirurgie Cardiovasculaire, Centre Hospitalier Universitaire Rangueil, Toulouse, France
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Valette H, Crouzel C, Syrota A, Fuseau C, Bourachot ML. Canine myocardial dihydropyridine binding sites: a positron emission tomographic study with the calcium channel inhibitor 11C-S11568. Life Sci 1994; 55:1471-7. [PMID: 7968214 DOI: 10.1016/0024-3205(94)00688-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The in vivo determination of the density of dihydropyridine (DHP) binding sites will allow the assessment of pathophysiological changes associated with heart disease. The calcium channel antagonist S 11568: (+/-)(amino-7 dioxa-2,5 heptyl)-2(dichloro -2,3 phenyl) -4 methyl-6dihydro -1,4 pyridine has an in vitro profile of high potency and of high selectivity for the L-type Ca2+ channel. S 11568 was labelled by a reaction between 11C-diazomethane and the precursor 6-(7-amino-2,5-dioxa heptyl)-4-(2,3-dichloro phenyl)-5-(ethoxycarbonyl)-2 methyl-1,4 dihydro nicotinic acid. (+)-PN 200 110, a DHP with in vitro high affinity for the L-type Ca2+ channel, was also radiolabeled. Positron emission tomographic (PET) studies of both 11C-DHP myocardial uptake were performed in Beagle dogs. 11C-(+)-PN 200 110 had a rapid wash-out from myocardium. In contrary, after a bolus injection, 11C-S 11568 myocardial concentration increased to reach a maximum in 1-2 minutes and then remained in a plateau with a slight downslope while the blood concentration fell rapidly. Myocardial uptake was 2 to 4 fold higher than lung uptake, leading to a good contrast on PET images. Pre-treatment with unlabeled S 11568 (2 mumol/kg or 6 mumol/kg over 15 minutes) reduced myocardial uptake by 60% and 80%, respectively. Specific binding was estimated during a displacement experiment: bolus of unlabeled S 11568: 1 mumol/kg followed by a continuous infusion of 3 mumol/kg over 2 hours. It was found to represent 80% of the total binding. To assess influence of S 11568 on coronary blood flow and therefore on the myocardial tracer delivery, coronary blood flow was measured using 15O-H2O and PET at baseline and following bolus injections of 0.4, 0.8, 2 mumol/kg of S 11568. Only the higher dose increased coronary blood flow. This is the in vivo demonstration of the binding characteristics to myocardial tissue of a DHP ligand. Such properties make S 11568 suitable for PET experiments. The studies of DHP binding sites will provided new insights concerning physiological situations as well as heart disease.
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Affiliation(s)
- H Valette
- Service Hospitalier Frédéric Joliot, DRIPP-CEA, Orsay, France
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Lefroy DC, de Silva R, Choudhury L, Uren NG, Crake T, Rhodes CG, Lammertsma AA, Boyd H, Patsalos PN, Nihoyannopoulos P. Diffuse reduction of myocardial beta-adrenoceptors in hypertrophic cardiomyopathy: a study with positron emission tomography. J Am Coll Cardiol 1993; 22:1653-60. [PMID: 8227834 DOI: 10.1016/0735-1097(93)90591-n] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES This study was conducted to determine the myocardial beta-adrenoceptor density as a marker of sympathetic function in patients with hypertrophic cardiomyopathy and normal control subjects. BACKGROUND Although some cases of hypertrophic cardiomyopathy are familial with an autosomal dominant pattern of inheritance, there remains a substantial proportion of cases in which neither a family history nor genetic abnormalities can be demonstrated. Additional abnormalities, both genetic and acquired, may be important in the phenotypic expression of this condition. Clinical features of the disease and metabolic studies suggest an increased activity of the sympathetic nervous system. METHODS Eleven patients with hypertrophic cardiomyopathy, none of whom had previously received beta-blocking drugs, and eight normal control subjects underwent positron emission tomography to evaluate regional left ventricular beta-adrenoceptor density and myocardial blood flow using carbon-11-labeled CGP 12177 and oxygen-15-labeled water as tracers. Plasma catecholamines were also measured. RESULTS Mean (+/- SD) myocardial beta-adrenoceptor density was significantly less in the hypertrophic cardiomyopathy group than in the control group (7.70 +/- 1.86 vs. 11.50 +/- 2.18 pmol/g tissue, p < 0.001). Myocardial blood flow was similar in both groups (0.91 +/- 0.22 vs. 0.91 +/- 0.21 ml/min per g, p = NS). The distribution of beta-adrenoceptor density was uniform throughout the left ventricle in both groups. In the hypertrophic cardiomyopathy group, there was no correlation between regional wall thickness and myocardial beta-adrenoceptor density. There were no significant differences in either plasma norepinephrine or epinephrine concentrations between the two groups. CONCLUSIONS There is a diffuse reduction in myocardial beta-adrenoceptor density in patients with hypertrophic cardiomyopathy in the absence of significantly elevated circulating catecholamine concentrations. This most likely reflects downregulation of myocardial beta-adrenoceptors secondary to increased myocardial concentrations of norepinephrine and is consistent with the hypothesis that cardiac sympathetic drive is increased in this condition.
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Affiliation(s)
- D C Lefroy
- Medical Research Council (MRC) Cyclotron Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, England, United Kingdom
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Abstract
Diastolic dysfunction is an important cause of symptoms in patients with various types of cardiac disease. Increased left ventricular diastolic pressure may lead to pulmonary congestion, even in the setting of normal left ventricular systolic function. Although the physiology of diastolic function is complex, left ventricular diastolic pressure may become elevated through one of three broad mechanisms. Abnormalities intrinsic to the left ventricle may include 1) impaired left ventricular relaxation, a finding that is common in most cardiac diseases and may be particularly important during ischemia; 2) increased left ventricular wall thickness relative to cavity volume, which will shift the diastolic pressure-volume relation such that the same volume is associated with a higher pressure; and 3) increased myocardial stiffness, which is thought to be associated with interstitial fibrosis or scar tissue formation. In addition, diastolic pressures may become elevated because of factors extrinsic to the left ventricle. These may include 1) increased central blood volume, which will increase left ventricular pressure without altering the left ventricular pressure-volume relation; and 2) ventricular interaction mediated by pericardial restraint, which may cause a parallel upward shift of the diastolic pressure-volume relation. Treatment of the factors extrinsic to the left ventricle tends to be much more successful than treating abnormalities that are intrinsic to the ventricle. Improved understanding of myocardial relaxation at the cellular level and delineation of the molecular regulation of myocyte hypertrophy and fibroblast proliferation may lead to new and innovative approaches to the treatment of heart failure.
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Affiliation(s)
- S E Litwin
- Charles A. Dana Research Institute, Boston, Massachusetts
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Willens HJ, Kessler KM. Severe pulmonary hypertension associated with diastolic left ventricular dysfunction. Chest 1993; 103:1877-83. [PMID: 8404117 DOI: 10.1378/chest.103.6.1877] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- H J Willens
- Department of Medicine, University of Miami School of Medicine, FLA
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Sanada H, Shimizu M, Sugihara N, Shimizu K, Ino H, Takeda R. Increased left atrial chamber stiffness in hypertrophic cardiomyopathy. BRITISH HEART JOURNAL 1993; 69:31-5. [PMID: 8457391 PMCID: PMC1024912 DOI: 10.1136/hrt.69.1.31] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To investigate left atrial chamber stiffness and its influence on left atrial and left ventricular functions in hypertrophic cardiomyopathy. DESIGN Prospective study. SETTING Department of internal medicine in a university teaching hospital. PATIENTS Five control subjects, six patients with essential hypertension, and 11 patients with hypertrophic cardiomyopathy. INTERVENTIONS Measurement of left atrial pressure by a tip micromanometer and of real-time left atrial volume from left atrial cineangiograms. MAIN OUTCOME MEASURE Left atrial stiffness constant determined by fitting the ascending limb of the v loop of the left atrial pressure-volume relation to an exponential curve. RESULTS The mean (SD) left atrial chamber stiffness constant was significantly larger in patients with hypertrophic cardiomyopathy than in controls (0.063 (0.018) v 0.041 (0.006), p < 0.05) and was correlated with left ventricular wall thickness (r = 0.560, p < 0.01). Left atrial reservoir volume (left atrial emptying volume before atrial contraction) was significantly smaller in patients with hypertrophic cardiomyopathy than in the controls (7.3 (2.1) v 12.5 (4.4) ml/m2, p < 0.01) and was inversely correlated with the left atrial chamber stiffness constant (r = -0.598, p < 0.01). The cardiac index was inversely correlated with the left atrial chamber stiffness constant (r = -0.542, p < 0.01). CONCLUSIONS Left atrial chamber stiffness was increased in patients with hypertrophic cardiomyopathy and this affected the left atrial reservoir function. This may in turn have affected cardiac output.
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Affiliation(s)
- H Sanada
- Second Department of Internal Medicine, School of Medicine, Kanazawa University, Japan
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Miller JA, Chmielewski PA, Rampe D. [3H]PN200-110 and [3H]glibenclamide binding in normal and cardiomyopathic hamsters. GENERAL PHARMACOLOGY 1992; 23:1153-7. [PMID: 1336750 DOI: 10.1016/0306-3623(92)90304-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
1. We examined the binding of the Ca2+ channel ligand [3H]PN200-110 and the ATP-sensitive K+ channel ligand [3H]glibenclamide to brain and heart from cardiomyopathic hamsters and compared them to controls. 2. We found that [3H]PN200-110 binding site density was elevated in the heart, but not in the brain, of 30- and 180-day old cardiomyopathic hamsters when compared to controls. 3. [3H]Glibenclamide binding site density was greatly reduced in the heart of 180-day old cardiomyopathic animals compared with all other groups. 4. Quantitative autoradiography revealed that [3H]glibenclamide binding was elevated in several brain areas of 30-day old cardiomyopathic hamsters relative to controls. 5. It is concluded that alterations in both Ca2+ and K+ channels exist in the cardiomyopathic hamster.
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Affiliation(s)
- J A Miller
- Marion Merrell Dow Research Institute, Cincinnati, OH 45215
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44
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Takahashi T, Allen PD, Lacro RV, Marks AR, Dennis AR, Schoen FJ, Grossman W, Marsh JD, Izumo S. Expression of dihydropyridine receptor (Ca2+ channel) and calsequestrin genes in the myocardium of patients with end-stage heart failure. J Clin Invest 1992; 90:927-35. [PMID: 1326001 PMCID: PMC329948 DOI: 10.1172/jci115969] [Citation(s) in RCA: 165] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cytoplasmic free calcium ions (Ca2+) play a central role in excitation-contraction coupling of cardiac muscle. Abnormal Ca2+ handling has been implicated in systolic and diastolic dysfunction in patients with end-stage heart failure. The current study tests the hypothesis that expression of genes encoding proteins regulating myocardial Ca2+ homeostasis is altered in human heart failure. We analyzed RNA isolated from the left ventricular (LV) myocardium of 30 cardiac transplant recipients with end-stage heart failure (HF) and five organ donors (normal control), using cDNA probes specific for the cardiac dihydropyridine (DHP) receptor (the alpha 1 subunit of the DHP-sensitive Ca2+ channel) and cardiac calsequestrin of sarcoplasmic reticulum (SR). In addition, abundance of DHP binding sites was assessed by ligand binding techniques (n = 6 each for the patients and normal controls). There was no difference in the level of cardiac calsequestrin mRNA between the HF patients and normal controls. In contrast, the level of mRNA encoding the DHP receptor was decreased by 47% (P less than 0.001) in the LV myocardium from the patients with HF compared to the normal controls. The number of DHP binding sites was decreased by 35-48%. As reported previously, expression of the SR Ca(2+)-ATPase mRNA was also diminished by 50% (P less than 0.001) in the HF group. These data suggest that expression of the genes encoding the cardiac DHP receptor and SR Ca(2+)-ATPase is reduced in the LV myocardium from patients with HF. Altered expression of these genes may be related to abnormal Ca2+ handling in the failing myocardium, contributing to LV systolic and diastolic dysfunction in patients with end-stage heart failure.
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Affiliation(s)
- T Takahashi
- Indursky Laboratory of Molecular Cardiology, Beth Israel Hospital, Boston, Massachusetts 02215
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Hoehner PJ, Blanck TJ, Roy R, Rosenthal RE, Fiskum G. Alteration of voltage-dependent calcium channels in canine brain during global ischemia and reperfusion. J Cereb Blood Flow Metab 1992; 12:418-24. [PMID: 1314842 DOI: 10.1038/jcbfm.1992.59] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Elevated intracellular calcium (iCa2+) plays an important role in the pathophysiology of ischemic brain damage. The mechanisms by which iCa2+ increases are uncertain. Recent evidence implicates the voltage-dependent calcium channel (VDCC) as a likely site for the alteration in Ca2+ homeostasis during ischemia. The purpose of this study was to determine whether VDCCs are altered by global ischemia and reperfusion in a canine cardiac arrest, resuscitation model. We employed the radioligand, [3H]PN200-110, to quantitate the equilibrium binding characteristics of the VDCCs in the cerebral cortex. Twenty-five adult beagles were separated into four experimental groups: (a) nonischemic controls, (b) those undergoing 10-min ventricular fibrillation and apnea, (c) those undergoing 10-min ventricular fibrillation and apnea followed by spontaneous circulation and controlled respiration for 2 and (d) 24 h. Brain cortex samples were taken prior to killing of the animal, frozen immediately in liquid nitrogen, and crude synaptosomal membranes isolated by differential centrifugation/filtration. After 10 min of ischemia the maximal binding (Bmax) of [3H]PN200-110 increased to greater than 250% of control values (control Bmax 11.16 +/- 0.98; ischemic 28.35 +/- 2.78 fmol/mg protein; p less than 0.05). Bmax returned to near control values after 2 h of reperfusion but remained significantly greater than the control at 24 h. Although the affinity constant (Kd) (control = 0.12 +/- 0.03 nM) appeared to increase with ischemia and normalize with reperfusion, the changes were not statistically significant. We conclude that the binding of [3H]PN200-110 to L-type VDCCs is increased after 10 min of global ischemia/anoxia produced by ventricular fibrillation and apnea in the dog.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P J Hoehner
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD
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Brodde OE, Hundhausen HJ, Zerkowski HR, Michel MC. Lack of effect of chronic calcium antagonist treatment on beta 1- and beta 2-adrenoceptors in right atria from patients with or without heart failure. Br J Clin Pharmacol 1992; 33:269-74. [PMID: 1315561 PMCID: PMC1381274 DOI: 10.1111/j.1365-2125.1992.tb04034.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
1. We studied the effects of chronic calcium antagonist (calcium entry blocker, CEB; nifedipine, verapamil, diltiazem) treatment on beta-adrenoceptor density (assessed by (-)-[125I]-iodocyanopindolol [ICYP] binding) and subtype distribution in right atria from 65 patients without apparent heart failure undergoing elective coronary artery bypass grafting (CAD-patients) and from 13 patients with moderate heart failure (NYHA class III to class III-IV) undergoing mitral valve replacement (MVD-patients). 2. In CAD-patients atrial beta-adrenoceptor density was 79.3 +/- 7.9 fmol ICYP bound mg-1 protein (n = 18), the beta 1:beta 2-adrenoceptor ratio 69:31%. Chronic CEB-treatment did not affect either atrial beta-adrenoceptor density or beta 1:beta 2-adrenoceptor ratio. 3. In contrast, in CAD-patients chronically treated with beta 1-adrenoceptor antagonists (atenolol, bisoprolol, metoprolol) and CEB, atrial beta-adrenoceptor density was significantly increased (108.6 +/- 10.5 fmol ICYP bound mg-1 protein, n = 21); this increase was due to a selective increase in beta 1-adrenoceptors. 4. In MVD-patients atrial beta-adrenoceptor density (55.5 +/- 8.7 fmol ICYP bound mg-1 protein, n = 7) was significantly lower (P less than 0.05) than in CAD-patients; beta 1:beta 2-adrenoceptor ratio, however, was not changed (67:33%). Chronic CEB-treatment of MVD-patients did not prevent the decrease in atrial beta-adrenoceptors. 5. We conclude that chronic CEB-treatment does not affect human right atrial beta-adrenoceptor density, either in patients without apparent heart failure or in patients with moderate heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- O E Brodde
- Department of Internal Medicine, University of Essen, Germany
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47
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Galinier M, Sénard JM, Valet P, Dréan G, Planat V, Arias A, Tran MA, Montastruc JL. Myocardial hypertrophy, cardiac beta-adrenoceptors and adenylate cyclase activity during sinoaortic denervation in dogs. Br J Pharmacol 1992; 105:341-6. [PMID: 1313724 PMCID: PMC1908648 DOI: 10.1111/j.1476-5381.1992.tb14256.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
1. The long-term effects of sinoaortic denervation on the development of left ventricular hypertrophy (assessed by the measurement of the ratio (R): heart weight/total body weight and LVT: left ventricular thickness), myocardial beta-adrenergic receptivity (measured by [125I]-cyanopindolol binding and adenylate cyclase activity) and plasma catecholamine levels (measured by h.p.l.c.) were investigated in three groups of dogs: normotensive controls (group 1), dogs made hypertensive by sinoaortic denervation and evaluated 1 (group 2) and 18 months (group 3) later. 2. Noradrenaline (NA) and adrenaline (A) plasma levels were 461 +/- 54 and 85 +/- 45 pg ml-1 in controls, 861 +/- 185 and 191 +/- 23 pg ml-1 in group 2 (P less than 0.05). They were normal in group 3 (426 +/- 132 and 110 +/- 16 pg ml-1). 3. R and LVT values were significantly (P less than 0.05) higher in sinoaortic denervated dogs (R = 7.7 +/- 0.1 and 7.8 +/- 0.2; LVT = 13.6 +/- 1.3 and 14.2 +/- 0.9 mm in groups 2 and 3 respectively) than in normotensive dogs (group 1: R = 6.7 +/- 0.1, LVT = 9.3 +/- 0.8 mm). 4. In group 1, the total number of beta-adrenoceptors (Bmax) was 37 +/- 11 and 29 +/- 6 fmol mg-1 protein in the left ventricle (LV) and right auricle (RA) respectively. In group 2, Bmax was significantly lower (10 +/- 3 in LV and 13 +/- 2 fmol mg-1 protein in RA, P less than 0.05) than in group 1. There was no difference between group 1 and group 3 (37 +/- 3 fmol mg-1 prot in LV and 31 +/- 3 fmol mg-1 protein in RA). 5. The percentage of beta 1-adrenoceptors was 82 +/- 4 in LV and 75 +/- 5 in RA in group 1. It was significantly lower (P less than 0.05) in groups 2 (LV: 33 +/- 6 and RA: 33 +/- 5) and 3 (LV: 59 +/- 3 and RA: 55 +/- 4). 6. Basal values of adenylate cyclase activity in LV significantly decreased after sinoaortic denervation.7. These data show that sinoaortic denervation is associated with left ventricular hypertrophy which appears early (1 month) and persists until 18 months despite the normalization of plasma catecholamine levels. The total number of myocardial beta-adrenoceptors is closely related to catecholamine levels but a selective decrease in beta 1-adrenoceptors is observed during cardiac hypertrophy. The fall in basal adenylate cyclase activity suggests that cardiac hypertrophy is associated with an impairment of transmembrane signalling.
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Affiliation(s)
- M Galinier
- Laboratoire de Pharmacologie Médicale et Clinique, INSERM U317, Faculté de Médecine, Toulouse, France
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Brodde OE, Broede A, Daul A, Kunde K, Michel MC. Receptor systems in the non-failing human heart. CELLULAR AND MOLECULAR ALTERATIONS IN THE FAILING HUMAN HEART 1992; 87 Suppl 1:1-14. [PMID: 1353955 DOI: 10.1007/978-3-642-72474-9_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Catecholamines acting through beta 1- and beta 2-adrenoceptors cause positive inotropic and chronotropic effects in the human heart. In recent years, however, evidence has accumulated that in the human heart also other receptor systems can affect heart rate and/or contractility. Positive inotropic effects can be mediated by receptor systems acting through accumulation of intracellular cAMP (Gs-protein coupled receptors such as 5-HT4-like, histamine H2, and vasoactive intestinal peptide) or by receptor systems acting independent of cAMP possibly through the phospholipase C/diacylglycerol/inositol-1,4,5-trisphosphate pathway (such as alpha 1-adrenergic, angiotensin II, and endothelin). In the non-failing human heart, however, activation of all these receptor systems induces only submaximal positive inotropic effects when compared with those caused by beta-adrenoceptor stimulation, indicating that in humans the cardiac beta-adrenoceptor-Gs-protein-adenylate cyclase pathway is the most powerful mechanism to increase heart rate and contractility. On the other hand, at least three receptor systems acting through inhibition of cAMP formation (Gi-protein coupled receptors) exist in the human heart: muscarinic M2-, adenosine A1-, and somatostatin-receptors. Activation of M2- and A1-receptors causes negative inotropic effects in the non-failing human heart: in atria activation of both receptors causes decreases in basal as well as in isoprenaline-stimulated force of contraction, but in ventricles only isoprenaline-stimulated force of contraction is depressed.
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Affiliation(s)
- O E Brodde
- Biochemisches Forschungslabor, Abteilung Nieren- und Hochdruckkrankheiten, Zentrum für Innere Medizin, Medizinische Klinik und Poliklinik, Universitätsklinikum Essen, FRG
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Bright JM, Golden AL. Evidence for or against the efficacy of calcium channel blockers for management of hypertrophic cardiomyopathy in cats. Vet Clin North Am Small Anim Pract 1991; 21:1023-34. [PMID: 1683045 DOI: 10.1016/s0195-5616(91)50110-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The positive lusitropic and direct coronary vasodilating properties of the calcium channel blocking agents are beneficial therapeutic effects not provided by the beta-adrenergic blocking agents for the management of feline HCM. Data from cats studied at the University of Tennessee suggest that diltiazem more consistently alleviates clinical signs and more effectively prolongs survival in cats with HCM than either propranolol or verapamil. Orally administered diltiazem appears to have sustained beneficial effects on left ventricular filling and cardiac performance based on its ability to reduce resting heart rate, decrease blood lactate concentration, increase venous oxygen tension, improve echocardiographic parameters, and resolve radiographic abnormalities. Long-term diltiazem administration may also reverse myocardial hypertrophy in some patients. There appear to be few if any side effects of this drug. Diltiazem, therefore, provides a safe and effective approach for the management of feline HCM.
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Affiliation(s)
- J M Bright
- University of Tennessee College of Veterinary Medicine, Knoxville
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Vasan RS. Hypertrophic cardiomyopathy: disorder to be rechristened? Int J Cardiol 1991; 32:413-4. [PMID: 1791096 DOI: 10.1016/0167-5273(91)90310-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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