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Galow AM, Brenmoehl J, Hoeflich A. Synergistic effects of hormones on structural and functional maturation of cardiomyocytes and implications for heart regeneration. Cell Mol Life Sci 2023; 80:240. [PMID: 37541969 PMCID: PMC10403476 DOI: 10.1007/s00018-023-04894-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/18/2023] [Accepted: 07/22/2023] [Indexed: 08/06/2023]
Abstract
The limited endogenous regenerative capacity of the human heart renders cardiovascular diseases a major health threat, thus motivating intense research on in vitro heart cell generation and cell replacement therapies. However, so far, in vitro-generated cardiomyocytes share a rather fetal phenotype, limiting their utility for drug testing and cell-based heart repair. Various strategies to foster cellular maturation provide some success, but fully matured cardiomyocytes are still to be achieved. Today, several hormones are recognized for their effects on cardiomyocyte proliferation, differentiation, and function. Here, we will discuss how the endocrine system impacts cardiomyocyte maturation. After detailing which features characterize a mature phenotype, we will contemplate hormones most promising to induce such a phenotype, the routes of their action, and experimental evidence for their significance in this process. Due to their pleiotropic effects, hormones might be not only valuable to improve in vitro heart cell generation but also beneficial for in vivo heart regeneration. Accordingly, we will also contemplate how the presented hormones might be exploited for hormone-based regenerative therapies.
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Affiliation(s)
- Anne-Marie Galow
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), 18196, Dummerstorf, Germany.
| | - Julia Brenmoehl
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), 18196, Dummerstorf, Germany
| | - Andreas Hoeflich
- Institute of Genome Biology, Research Institute for Farm Animal Biology (FBN), 18196, Dummerstorf, Germany
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2
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Gangitano E, Barbaro G, Susi M, Rossetti R, Spoltore ME, Masi D, Tozzi R, Mariani S, Gnessi L, Lubrano C. Growth Hormone Secretory Capacity Is Associated with Cardiac Morphology and Function in Overweight and Obese Patients: A Controlled, Cross-Sectional Study. Cells 2022; 11:cells11152420. [PMID: 35954264 PMCID: PMC9367721 DOI: 10.3390/cells11152420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/30/2022] [Accepted: 08/02/2022] [Indexed: 12/10/2022] Open
Abstract
Obesity is associated with increased cardiovascular morbidity. Adult patients with growth hormone deficiency (GHD) show morpho-functional cardiological alterations. A total of 353 overweight/obese patients are enrolled in the period between 2009 and 2019 to assess the relationships between GH secretory capacity and the metabolic phenotype, cardiovascular risk factors, body composition and cardiac echocardiographic parameters. All patients underwent GHRH + arginine test to evaluate GH secretory capacity, DEXA for body composition assessment and transthoracic echocardiography. Blood samples are also collected for the evaluation of metabolic parameters. In total, 144 patients had GH deficiency and 209 patients had normal GH secretion. In comparing the two groups, we found significant differences in body fat distribution with predominantly visceral adipose tissue accumulation in GHD patients. Metabolic syndrome is more prevalent in the GHD group. In particular, fasting glycemia, triglycerides and systolic and diastolic blood pressure are found to be linearly correlated with GH secretory capacity. Epicardial fat thickness, E/A ratio and indexed ventricular mass are worse in the GHD group. In the population studied, metabolic phenotype, body composition, cardiovascular risk factors and cardiac morphology are found to be related to the GH secretory capacity. GH secretion in the obese patient seems to be an important determinant of metabolic health.
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Affiliation(s)
- Elena Gangitano
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Giuseppe Barbaro
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Martina Susi
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Rebecca Rossetti
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Maria Elena Spoltore
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Davide Masi
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Rossella Tozzi
- Department of Molecular Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Stefania Mariani
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Lucio Gnessi
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Carla Lubrano
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy
- Correspondence:
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3
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Ratku B, Sebestyén V, Erdei A, Nagy EV, Szabó Z, Somodi S. Effects of adult growth hormone deficiency and replacement therapy on the cardiometabolic risk profile. Pituitary 2022; 25:211-228. [PMID: 35106704 PMCID: PMC8894188 DOI: 10.1007/s11102-022-01207-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/10/2022] [Indexed: 12/12/2022]
Abstract
Adult growth hormone deficiency (AGHD) is considered a rare endocrine disorder involving patients with childhood-onset and adult-onset growth hormone deficiency (AoGHD) and characterized by adverse cardiometabolic risk profile. Besides traditional cardiovascular risk factors, endothelial dysfunction, low-grade inflammation, impaired adipokine profile, oxidative stress and hypovitaminosis D may also contribute to the development of premature atherosclerosis and higher cardiovascular risk in patients with AGHD. Growth hormone replacement has been proved to exert beneficial effects on several cardiovascular risk factors, but it is also apparent that hormone substitution in itself does not eliminate all cardiometabolic abnormalities associated with the disease. Novel biomarkers and diagnostic techniques discussed in this review may help to evaluate individual cardiovascular risk and identify patients with adverse cardiometabolic risk profile. In the absence of disease-specific guidelines detailing how to assess the cardiovascular status of these patients, we generally recommend close follow-up of the cardiovascular status as well as low threshold for a more detailed evaluation.
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Affiliation(s)
- Balázs Ratku
- Department of Emergency Medicine, Faculty of Medicine, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary
- Doctoral School of Health Sciences, University of Debrecen, Debrecen, Hungary
- Department of Emergency and Oxyology, Faculty of Health, University of Debrecen, Debrecen, Hungary
| | - Veronika Sebestyén
- Department of Emergency Medicine, Faculty of Medicine, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary
- Doctoral School of Health Sciences, University of Debrecen, Debrecen, Hungary
| | - Annamária Erdei
- Division of Endocrinology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre V Nagy
- Division of Endocrinology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Szabó
- Department of Emergency Medicine, Faculty of Medicine, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary
| | - Sándor Somodi
- Department of Emergency Medicine, Faculty of Medicine, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary.
- Division of Endocrinology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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4
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Hinojosa-Amaya JM, Varlamov EV, Yedinak CG, Cetas JS, McCartney S, Banskota S, Fleseriu M. Echocardiographic findings in acromegaly: prevalence of concentric left ventricular remodeling in a large single-center cohort. J Endocrinol Invest 2021; 44:2665-2674. [PMID: 33893617 DOI: 10.1007/s40618-021-01579-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/13/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE Acromegaly is a rare disease and is associated with increased cardiovascular (CV) morbidity and mortality, especially in patients with uncontrolled disease. We aimed to analyze the prevalence and severity of cardiomyopathy and valvular heart disease in a large cohort of patients with a confirmed acromegaly diagnosis, at baseline and after treatment. METHODS We retrospectively reviewed an institutional approved database; 190 patients with confirmed acromegaly and follow-up data available (years 2006-2018). Patients with at least one baseline echocardiogram, were included. Demographic, disease control and echocardiogram variables were collected for analysis. RESULTS Of the 190 patients 110 (58%) had a baseline echocardiogram and 43 (39.1%) had at least one follow-up echocardiogram after surgical, medical or multimodal treatment. Baseline left ventricular hypertrophy (LVH) prevalence was 17.8% (64.7% concentric; 35.3% eccentric), diastolic and systolic dysfunction, and overt cardiomyopathy with heart failure were 15.8, 7.9, and 3.0%, respectively. Concentric remodeling of the left ventricle (LV) was noted in 31.4% of patients without LVH. Valve defects were found in 87.3% of patients (14.6% with significant valvular heart disease). CONCLUSION Early diagnosis of acromegaly and disease control should be attempted to prevent LVH/LV dysfunction and development of valvular heart disease. Concentric LV remodeling develops prior to obvious LV hypertrophy in almost a third of patients with acromegaly, which is a novel finding. Similar to other epidemiological studies, we found a high prevalence of LVH/LV dysfunction. Although possible, reversal of systolic and diastolic dysfunction is sporadic after treatment of acromegaly.
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Affiliation(s)
- J M Hinojosa-Amaya
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Endocrinology Division, Department of Medicine, Hospital Universitario "Dr. José E. González", Universidad Autonóma de Nuevo León, Monterrey, Nuevo León, Mexico
| | - E V Varlamov
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Department of Medicine (Endocrinology, Diabetes and Clinical Nutrition), Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR, 97239, USA
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
| | - C G Yedinak
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
| | - J S Cetas
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Operative Care Division, Portland Veterans Administration Hospital, 3710 SW US Veterans Hospital Road, Portland, OR, USA
| | - S McCartney
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
| | - S Banskota
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA
| | - M Fleseriu
- Department of Neurological Surgery, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA.
- Department of Medicine (Endocrinology, Diabetes and Clinical Nutrition), Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR, 97239, USA.
- Pituitary Center, Oregon Health & Science University, Mail Code CH8N, 3303 South Bond Ave, Portland, OR, 97239, USA.
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Çetin E. Protective effect of ghrelin against tilmicosin-induced left ventricular dysfunction in rats. Can J Physiol Pharmacol 2019; 97:407-412. [DOI: 10.1139/cjpp-2018-0511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This study was conducted to investigate the possible protective effects of ghrelin against tilmicosin-induced acute ventricular dysfunction in rats. Forty adult male Sprague Dawley rats were randomly divided into 4 equal groups: control, ghrelin, tilmicosin, and ghrelin + tilmicosin. The left ventricular structural and functional parameters together with cardiac biomarker levels were evaluated. The results showed that tilmicosin treatment alone significantly decreased the left ventricular fractional shortening, left ventricular ejection fraction, left ventricular stroke volume, and cardiac output when compared with control group. In addition, tilmicosin led to a significant increase in left ventricular internal dimension in systole and left ventricular fractional end-systolic volume. At the same time, serum lactate dehydrogenase, creatine kinase, and creatine kinase-myocardial B fraction levels were significantly increased in tilmicosin-treated group when compared with control group. However, ghrelin pretreatment significantly prevented the left ventricular internal dimension in systole, left ventricular fractional end-systolic volume, left ventricular stroke volume, left ventricular ejection fraction, left ventricular fractional shortening, and cardiac output changes caused by tilmicosin. Moreover, ghrelin pretreatment could reduce significantly serum lactate dehydrogenase, creatine kinase, and creatine kinase-myocardial B fraction levels. These data indicated that ghrelin treatment may provide a protective effect against tilmicosin-induced left ventricular systolic dysfunction.
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Affiliation(s)
- Ebru Çetin
- Department of Physiology, Faculty of Veterinary Medicine, Erciyes University, 38039, Kayseri, Turkey
- Department of Physiology, Faculty of Veterinary Medicine, Erciyes University, 38039, Kayseri, Turkey
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Gadelha MR, Kasuki L, Lim DST, Fleseriu M. Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update. Endocr Rev 2019; 40:268-332. [PMID: 30184064 DOI: 10.1210/er.2018-00115] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/26/2018] [Indexed: 12/19/2022]
Abstract
Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.
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Affiliation(s)
- Mônica R Gadelha
- Neuroendocrinology Research Center/Endocrine Section and Medical School, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Neuroendocrine Section, Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, Brazil.,Neuropathology and Molecular Genetics Laboratory, Instituto Estadual do Cérebro Paulo Niemeyer, Rio de Janeiro, Brazil
| | - Leandro Kasuki
- Neuroendocrinology Research Center/Endocrine Section and Medical School, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Neuroendocrine Section, Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, Brazil.,Endocrine Unit, Hospital Federal de Bonsucesso, Rio de Janeiro, Brazil
| | - Dawn S T Lim
- Department of Endocrinology, Singapore General Hospital, Singapore, Singapore
| | - Maria Fleseriu
- Department of Endocrinology, Diabetes and Metabolism, Oregon Health and Science University, Portland, Oregon.,Department of Neurological Surgery, Oregon Health and Science University, Portland, Oregon.,Northwest Pituitary Center, Oregon Health and Science University, Portland, Oregon
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7
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Gonzalez S, Windram JD, Sathyapalan T, Javed Z, Clark AL, Atkin SL. Effects of human recombinant growth hormone on exercise capacity, cardiac structure, and cardiac function in patients with adult-onset growth hormone deficiency. J Int Med Res 2017; 45:1708-1719. [PMID: 28856940 PMCID: PMC5805223 DOI: 10.1177/0300060517723798] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Objective Epidemiological studies suggest that adult-onset growth hormone deficiency
(AGHD) might increase the risk of death from cardiovascular causes. Methods This was a 6-month double-blind, placebo-controlled, randomised, cross-over
trial followed by a 6-month open-label phase. Seventeen patients with AGHD
received either recombinant human growth hormone (rGH) (0.4 mg injection
daily) or placebo for 12 weeks, underwent washout for 2 weeks, and were then
crossed over to the alternative treatment for a further 12 weeks. Cardiac
magnetic resonance imaging, echocardiography, and cardiopulmonary exercise
testing were performed at baseline, 12 weeks, 26 weeks, and the end of the
open phase (12 months). The results were compared with those of 16 age- and
sex-matched control subjects. Results At baseline, patients with AGHD had a significantly higher systolic blood
pressure, ejection fraction, and left ventricular mass than the control
group, even when corrected for body surface area. Treatment with rGH
normalised the insulin-like growth factor 1 concentration without an effect
on exercise capacity, cardiac structure, or cardiac function. Conclusion Administration of rGH therapy for 6 to 9 months failed to normalise the
functional and structural cardiac differences observed in patients with AGHD
when compared with a control group.
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Affiliation(s)
- S Gonzalez
- 1 Department of Diabetes, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, West Yorkshire, UK
| | - J D Windram
- 2 Department of Academic Cardiology, Hull Royal Infirmary, Kingston upon Hull, UK
| | - T Sathyapalan
- 3 Academic Endocrinology, Diabetes and Metabolism, 12195 Hull York Medical School , University of Hull, UK
| | - Z Javed
- 3 Academic Endocrinology, Diabetes and Metabolism, 12195 Hull York Medical School , University of Hull, UK
| | - A L Clark
- 2 Department of Academic Cardiology, Hull Royal Infirmary, Kingston upon Hull, UK
| | - S L Atkin
- 4 Weill Cornell Medical College Qatar, Doha, Qatar
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Weeks KL, Bernardo BC, Ooi JYY, Patterson NL, McMullen JR. The IGF1-PI3K-Akt Signaling Pathway in Mediating Exercise-Induced Cardiac Hypertrophy and Protection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1000:187-210. [PMID: 29098623 DOI: 10.1007/978-981-10-4304-8_12] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Regular physical activity or exercise training can lead to heart enlargement known as cardiac hypertrophy. Cardiac hypertrophy is broadly defined as an increase in heart mass. In adults, cardiac hypertrophy is often considered a poor prognostic sign because it often progresses to heart failure. Heart enlargement in a setting of cardiac disease is referred to as pathological cardiac hypertrophy and is typically characterized by cell death and depressed cardiac function. By contrast, physiological cardiac hypertrophy, as occurs in response to chronic exercise training (i.e. the 'athlete's heart'), is associated with normal or enhanced cardiac function. The following chapter describes the morphologically distinct types of heart growth, and the key role of the insulin-like growth factor 1 (IGF1) - phosphoinositide 3-kinase (PI3K)-Akt signaling pathway in regulating exercise-induced physiological cardiac hypertrophy and cardiac protection. Finally we summarize therapeutic approaches that target the IGF1-PI3K-Akt signaling pathway which are showing promise in preclinical models of heart disease.
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Affiliation(s)
- Kate L Weeks
- Baker Heart & Diabetes Institute, P.O. Box 6492, Melbourne, VIC, 3004, Australia.
| | - Bianca C Bernardo
- Baker Heart & Diabetes Institute, P.O. Box 6492, Melbourne, VIC, 3004, Australia
| | - Jenny Y Y Ooi
- Baker Heart & Diabetes Institute, P.O. Box 6492, Melbourne, VIC, 3004, Australia
| | - Natalie L Patterson
- Baker Heart & Diabetes Institute, P.O. Box 6492, Melbourne, VIC, 3004, Australia
| | - Julie R McMullen
- Baker Heart & Diabetes Institute, P.O. Box 6492, Melbourne, VIC, 3004, Australia.
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Isgaard J, Arcopinto M, Karason K, Cittadini A. GH and the cardiovascular system: an update on a topic at heart. Endocrine 2015; 48:25-35. [PMID: 24972804 PMCID: PMC4328125 DOI: 10.1007/s12020-014-0327-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/04/2014] [Indexed: 01/06/2023]
Abstract
In this review, the importance of growth hormone (GH) for the maintenance of normal cardiac function in adult life is discussed. Physiological effects of GH and underlying mechanisms for interactions between GH and insulin-like growth factor I (IGF-I) and the cardiovascular system are covered as well as the cardiac dysfunction caused both by GH excess (acromegaly) and by GH deficiency in adult hypopituitary patients. In both acromegaly and adult GH deficiency, there is also increased cardiovascular morbidity and mortality possibly linked to aberrations in GH status. Finally, the status of the GH/IGF-I system in relation to heart failure and the potential of GH as a therapeutic tool in the treatment of heart failure are reviewed in this article.
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Affiliation(s)
- Jörgen Isgaard
- Laboratory of Experimental Endocrinology, Department of Internal Medicine, Sahlgrenska Academy, University of Gothenburg, Gröna Stråket 8, 413 45, Göteborg, Sweden,
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Chang PC, Wo HT, Lee HL, Wen MS, Chou CC. Paradoxical effects of KB-R7943 on arrhythmogenicity in a chronic myocardial infarction rabbit model. J Cardiol 2014; 66:80-7. [PMID: 25241015 DOI: 10.1016/j.jjcc.2014.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 07/22/2014] [Accepted: 08/05/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Na(+)/Ca(2+) exchanger blockade has been reported to be anti-arrhythmic in different models. The effects of KB-R7943, a Na(+)/Ca(2+) exchanger blocker, on arrhythmogenesis in hearts with chronic myocardial infarction (MI) remain unclear. METHODS Dual voltage and intracellular Ca(2+) (Cai) optical mapping was performed in nine rabbit hearts with chronic MI and four control hearts. Electrophysiology studies including inducibility of ventricular tachyarrhythmias, ventricular fibrillation dominant frequency, action potential, Cai alternans, Cai decay, and conduction velocity were performed. The same protocol was repeated in the presence of KB-R7943 (0.5, 1, and 5μM) after the baseline studies. RESULTS KB-R7943 was effective in suppressing afterdepolarizations and spontaneous ventricular tachyarrhythmias in hearts with chronic MI. Surprisingly, KB-R7943 increased the inducibility of ventricular tachyarrhythmias in a dose-dependent manner (11%, 11%, 22%, and 56% at baseline and with 0.5, 1, and 5μM KB-R7943, respectively, p=0.02). Optical mapping analysis revealed that the underlying mechanisms of the induced ventricular tachyarrhythmias were probably spatially discordant alternans with wave breaks and rotors. Further analysis showed that KB-R7943 significantly enhanced both action potential (p=0.033) and Cai (p=0.001) alternans, prolonged Cai decay (tau value) in a dose-dependent manner (p=0.004), and caused heterogeneous conduction delay especially at peri-infarct zones during rapid burst pacing. In contrast, KB-R7943 had insignificant effects in control hearts. CONCLUSIONS In this chronic MI rabbit model, KB-R7943 has contrasting effects on arrhythmogenesis, suppressing afterdepolarizations and spontaneous ventricular tachyarrhythmias, but enhancing the inducibility of tachyarrhythmias. The mechanism is probably the enhanced spatially discordant alternans because of prolonged Cai decay and heterogeneous conduction delay.
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Affiliation(s)
- Po-Cheng Chang
- Division of Cardiology, Department of Internal Medicine, Linko, Chang Gung Memorial Hospital, Taipei, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Hung-Ta Wo
- Division of Cardiology, Department of Internal Medicine, Linko, Chang Gung Memorial Hospital, Taipei, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Hui-Ling Lee
- Chang Gung University College of Medicine, Taoyuan, Taiwan; Department of Anesthesia, Chang Gung Memorial Hospital, Taipei, Taiwan
| | - Ming-Shien Wen
- Division of Cardiology, Department of Internal Medicine, Linko, Chang Gung Memorial Hospital, Taipei, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Chung-Chuan Chou
- Division of Cardiology, Department of Internal Medicine, Linko, Chang Gung Memorial Hospital, Taipei, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan.
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11
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Lu D, Liu J, Jiao J, Long B, Li Q, Tan W, Li P. Transcription factor Foxo3a prevents apoptosis by regulating calcium through the apoptosis repressor with caspase recruitment domain. J Biol Chem 2013; 288:8491-8504. [PMID: 23382383 DOI: 10.1074/jbc.m112.442061] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Apoptosis can occur in the myocardium under a variety of pathological conditions, including myocardial infarction and heart failure. The forkhead family of transcription factor Foxo3a plays a pivotal role in apoptosis; however, its role in regulating cardiac apoptosis remains to be fully elucidated. We showed that enforced expression of Foxo3a inhibits cardiomyocyte apoptosis, whereas knockdown of endogenous Foxo3a sensitizes cardiomyocytes to undergo apoptosis. The apoptosis repressor with caspase recruitment domain (ARC) is a potent anti-apoptotic protein. Here, we demonstrate that it attenuates the release of calcium from the sarcoplasmic reticulum and inhibits calcium elevations in the cytoplasm and mitochondria provoked by oxidative stress in cardiomyocytes. Furthermore, Foxo3a is shown to maintain cytoplasmic and mitochondrial calcium homeostasis through ARC. We observed that Foxo3a knock-out mice exhibited enlarged myocardial infarction sizes upon ischemia/reperfusion, and ARC transgenic mice demonstrated reduced myocardial infarction and balanced calcium levels in mitochondria and sarcoplasmic reticulum. Moreover, we showed that Foxo3a activates ARC expression by directly binding to its promoter. This study reveals that Foxo3a maintains calcium homeostasis and inhibits cardiac apoptosis through trans-activation of the ARC promoter. These findings provided novel evidence that Foxo3a and ARC constitute an anti-apoptotic pathway that regulates calcium homeostasis in the heart.
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Affiliation(s)
- Daoyuan Lu
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinping Liu
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianqin Jiao
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Long
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qian Li
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiqi Tan
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Peifeng Li
- College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612.
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12
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Stengel A, Taché Y. Ghrelin - a pleiotropic hormone secreted from endocrine x/a-like cells of the stomach. Front Neurosci 2012; 6:24. [PMID: 22355282 PMCID: PMC3280431 DOI: 10.3389/fnins.2012.00024] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Accepted: 01/29/2012] [Indexed: 12/13/2022] Open
Abstract
The gastric X/A-like endocrine cell receives growing attention due to its peptide products with ghrelin being the best characterized. This peptide hormone was identified a decade ago as a stimulator of food intake and to date remains the only known peripherally produced and centrally acting orexigenic hormone. In addition, subsequent studies identified numerous other functions of this peptide including the stimulation of gastrointestinal motility, the maintenance of energy homeostasis and an impact on reproduction. Moreover, ghrelin is also involved in the response to stress and assumed to play a role in coping functions and exert a modulatory action on immune pathways. Our knowledge on the regulation of ghrelin has markedly advanced during the past years by the identification of the ghrelin acylating enzyme, ghrelin-O-acyltransferase, and by the description of changes in expression, activation, and release under different metabolic as well as physically and psychically challenging conditions. However, our insight on regulatory processes of ghrelin at the cellular and subcellular levels is still very limited and warrants further investigation.
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Affiliation(s)
- Andreas Stengel
- Division Psychosomatic Medicine and Psychotherapy, Department of Medicine, Charité - Universitätsmedizin Berlin Berlin, Germany
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A crucial role of activin A-mediated growth hormone suppression in mouse and human heart failure. PLoS One 2011; 6:e27901. [PMID: 22216087 PMCID: PMC3247209 DOI: 10.1371/journal.pone.0027901] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 10/27/2011] [Indexed: 12/15/2022] Open
Abstract
Infusion of bone marrow-derived mononuclear cells (BMMNC) has been reported to ameliorate cardiac dysfunction after acute myocardial infarction. In this study, we investigated whether infusion of BMMNC is also effective for non-ischemic heart failure model mice and the underlying mechanisms. Intravenous infusion of BMMNC showed transient cardioprotective effects on animal models with dilated cardiomyopathy (DCM) without their engraftment in heart, suggesting that BMMNC infusion improves cardiac function via humoral factors rather than their differentiation into cardiomyocytes. Using conditioned media from sorted BMMNC, we found that the cardioprotective effects were mediated by growth hormone (GH) secreted from myeloid (Gr-1(+)) cells and the effects was partially mediated by signal transducer and activator of transcription 3 in cardiomyocytes. On the other hand, the GH expression in Gr-1(+) cells was significantly downregulated in DCM mice compared with that in healthy control, suggesting that the environmental cue in heart failure might suppress the Gr-1(+) cells function. Activin A was upregulated in the serum of DCM models and induced downregulation of GH levels in Gr-1(+) cells and serum. Furthermore, humoral factors upregulated in heart failure including angiotensin II upregulated activin A in peripheral blood mononuclear cells (PBMNC) via activation of NFκB. Similarly, serum activin A levels were also significantly higher in DCM patients with heart failure than in healthy subjects and the GH levels in conditioned medium from PBMNC of DCM patients were lower than that in healthy subjects. Inhibition of activin A increased serum GH levels and improved cardiac function of DCM model mice. These results suggest that activin A causes heart failure by suppressing GH activity and that inhibition of activin A might become a novel strategy for the treatment of heart failure.
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Castellano G, Affuso F, Conza PD, Fazio S. The GH/IGF-1 Axis and Heart Failure. Curr Cardiol Rev 2011; 5:203-15. [PMID: 20676279 PMCID: PMC2822143 DOI: 10.2174/157340309788970306] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 01/22/2009] [Accepted: 01/23/2009] [Indexed: 01/24/2023] Open
Abstract
The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis regulates cardiac growth, stimulates myocardial contractility and influences the vascular system. The GH/IGF-1 axis controls intrinsic cardiac contractility by enhancing the intracellular calcium availability and regulating expression of contractile proteins; stimulates cardiac growth, by increasing protein synthesis; modifies systemic vascular resistance, by activating the nitric oxide system and regulating non-endothelial-dependent actions. The relationship between the GH/IGF-1 axis and the cardiovascular system has been extensively demonstrated in numerous experimental studies and confirmed by the cardiac derangements secondary to both GH excess and deficiency. Several years ago, a clinical non-blinded study showed, in seven patients with idiopathic dilated cardiomyopathy and chronic heart failure (CHF), a significant improvement in cardiac function and structure after three months of treatment with recombinant GH plus standard therapy for heart failure. More recent studies, including a small double-blind placebo-controlled study on GH effects on exercise tolerance and cardiopulmonary performance, have shown that GH benefits patients with CHF secondary to both ischemic and idiopathic dilated cardiomyopathy. However, conflicting results emerge from other placebo-controlled trials. These discordant findings may be explained by the degree of CHF-associated GH resistance. In conclusion, we believe that more clinical and experimental studies are necessary to exactly understand the mechanisms that determine the variable sensitivity to GH and its positive effects in the failing heart.
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Affiliation(s)
- Graziella Castellano
- Department of Internal Medicine, School of Medicine, University of Naples "Federico II", Naples, Italy
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15
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Isgaard J, Granata R. Ghrelin in cardiovascular disease and atherogenesis. Mol Cell Endocrinol 2011; 340:59-64. [PMID: 21458527 DOI: 10.1016/j.mce.2011.03.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 03/01/2011] [Accepted: 03/01/2011] [Indexed: 11/16/2022]
Abstract
Although initially associated with regulation of appetite, the cardiovascular system has also been recognized as a potentially important target for ghrelin. Moreover, a limited number of clinical studies suggest a role for ghrelin in the treatment of congestive heart failure. So far reported cardiovascular effects of growth hormone secretagogues and/or ghrelin include lowering of peripheral resistance, either direct at the vascular level and/or by modulating sympathetic nervous activity. Other observed effects indicate possible improvement of contractility and cardioprotective effects both in vivo and in vitro.Taken together, these results offer an interesting perspective on the future where further studies aiming at evaluating a role of GHS and ghrelin in the treatment of cardiovascular disease are warranted.
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Affiliation(s)
- Jörgen Isgaard
- Department of Internal Medicine, The Sahlgrenska Academy at the University of Gothenburg, Gröna Stråket 8, Gothenburg, Sweden.
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16
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Groban L, Lin M, Kassik KA, Ingram RL, Sonntag WE. Early-onset growth hormone deficiency results in diastolic dysfunction in adult-life and is prevented by growth hormone supplementation. Growth Horm IGF Res 2011; 21:81-88. [PMID: 21371927 PMCID: PMC3085723 DOI: 10.1016/j.ghir.2011.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 01/27/2011] [Accepted: 01/29/2011] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The primary goal of growth hormone (GH) replacement is to promote linear growth in children with growth hormone deficiency (GHD). GH and insulin-like growth factor-1 (IGF-1) are also known to have roles in cardiac development and as modulators of myocardial structure and function in the adult heart. However, little is known about cardiac diastolic function in young adults with childhood onset GH deficiency in which GH treatment was discontinued following puberty. The aim of the study was to evaluate the effects of long standing GHD and peri-pubertal or continuous GH replacement therapy on diastolic function in the adult dwarf rat. DESIGN The dwarf rat, which possesses a mutation in a transcription factor necessary for development of the somatotroph, does not exhibit the normal peri-pubertal rise in GH around day 28 and was used to model childhood or early-onset GHD (EOGHD). In another group of male dwarfs, GH replacement therapy was initiated at 4 weeks of age when GH pulsatility normally begins. Ten weeks after initiation of injections, GH-treated dwarf rats were divided into 2 groups; continued treatment with GH for 12 weeks (GH-replete) or treatment with saline for 12 weeks. This latter group models GH supplementation during adolescence with GHD beginning in adulthood (adult-onset GHD; AOGHD). Saline-treated heterozygous (HZ) rats were used as age-matched controls. At 26 weeks of age, cardiac function was assessed using invasive or noninvasive (conventional and tissue Doppler) indices of myocardial contractility and lusitropy. RESULTS Systolic function, as determined by echocardiography, was similar among groups. Compared with HZ rats and GH-replete dwarfs, the EOGHD group exhibited significant reductions in myocardial relaxation and increases in left ventricular filling pressure, indicative of moderate diastolic dysfunction. This was further associated with a decrease in the cardiac content of sarcoplasmic reticulum Ca(2+) ATPase (SERCA2), one of the important cardiac calcium regulatory proteins. Dwarfs supplemented with GH during the peri-adolescence stage, but not beyond (AOGHD), exhibited a subtle prolongation in the deceleration time to early filling. In contrast, continual GH replacement preserved diastolic function such that the cardiac phenotype of the GH-replete dwarfs resembled that of their age-matched HZ counterpart. DISCUSSION Our data indicate that GHD during adolescence leads to overt diastolic dysfunction in early adulthood and this is prevented by continual GH replacement therapy. Since discontinuation of GH replacement following adolescence only mitigated the lusitropic deficits that were observed in untreated dwarfs, GH treatment into adulthood could be beneficial.
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Affiliation(s)
- L Groban
- Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1009, USA.
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17
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Agarwal M, Naghi J, Philip K, Phan A, Willix RD, Schwarz ER. Growth hormone and testosterone in heart failure therapy. Expert Opin Pharmacother 2010; 11:1835-44. [PMID: 20486829 DOI: 10.1517/14656566.2010.485615] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Heart failure is a progressive disease affecting millions of people worldwide. The disease carries a significantly high morbidity and mortality risk. There are multiple pharmaceutical options to decrease this risk and prolong survival; however, despite optimization of medical management, several patients still await heart transplant, the only definitive cure for heart failure. To slow the progression of disease preventing need for transplantation, improve clinical symptoms, and improve heart failure outcomes, there is a persistent need to discover new therapeutic strategies. Of interest, low growth hormone and testosterone levels have been associated with a worsening degree of heart failure. Many studies have begun to show a clinical improvement in heart failure symptoms when these levels are corrected with hormonal therapy. These findings, although mixed, are promising and indicate that both testosterone and growth hormone therapy should be considered as adjunctive therapy in advanced heart failure patients. AREAS COVERED IN THIS REVIEW This review discusses the physiology of both of these natural hormones, their therapeutic effects in heart failure and data from the published literature on studies using growth hormone or testosterone in patients with chronic heart failure. An extensive search of PubMed was conducted for topics on heart failure, growth hormone, insulin-like growth factor, testosterone, their physiology and pathophysiology, and trials in which they have been used as therapeutic interventions between 1989 and 2009. WHAT THE READER WILL GAIN The reader will gain an understanding of the intricate balance of both of these hormones in the disease state of heart failure. In addition, the trials conducted using these hormones in pharmacotherapy for heart failure are discussed along with proposed theories for interstudy variability. TAKE HOME MESSAGE Testosterone deficiency and growth hormone resistance are positively associated with a poor state of heart failure. Treatment of deficiency improves outcomes in heart failure; however, there is a significant paucity of data with regard to testosterone and heart failure as well as a significant amount of study variability with growth hormone and heart failure.
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Affiliation(s)
- Megha Agarwal
- Cedars Sinai Medical Center Los Angeles, Cedars Sinai Heart Institute, 8700 Beverly Boulevard, Suite 6215, Los Angeles, California 90048, USA
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18
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Dai DF, Rabinovitch PS. Cardiac aging in mice and humans: the role of mitochondrial oxidative stress. Trends Cardiovasc Med 2010; 19:213-20. [PMID: 20382344 DOI: 10.1016/j.tcm.2009.12.004] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Age is a major risk factor for cardiovascular diseases, not only because it prolongs exposure to several other cardiovascular risks, but also owing to intrinsic cardiac aging, which reduces cardiac functional reserve, predisposes the heart to stress, and contributes to increased cardiovascular mortality in the elderly. Intrinsic cardiac aging in the murine model closely recapitulates age-related cardiac changes in humans, including left ventricular hypertrophy, fibrosis, and diastolic dysfunction. Cardiac aging in mice is accompanied by accumulation of mitochondrial protein oxidation, increased mitochondrial DNA mutations, increased mitochondrial biogenesis, as well as decreased cardiac SERCA2 protein. All of these age-related changes are significantly attenuated in mice overexpressing catalase targeted to mitochondria. These findings demonstrate the critical role of mitochondrial reactive oxygen species in cardiac aging and support the potential application of mitochondrial antioxidants to cardiac aging and age-related cardiovascular diseases.
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Affiliation(s)
- Dao-Fu Dai
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
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19
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Affiliation(s)
- Joshua I Goldhaber
- Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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20
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Long-Term Effects of Growth Hormone on Infarct Size and Left Ventricular Function in Sheep With Coronary Artery Occlusion. J Cardiovasc Pharmacol 2010; 55:255-61. [DOI: 10.1097/fjc.0b013e3181cf9190] [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: 11/25/2022]
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21
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Li X, Chu W, Liu J, Xue X, Lu Y, Shan H, Yang B. Antiarrhythmic Properties of Long-Term Treatment with Matrine in Arrhythmic Rat Induced by Coronary Ligation. Biol Pharm Bull 2009; 32:1521-6. [DOI: 10.1248/bpb.32.1521] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Xuelian Li
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
| | - Weiming Chu
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
| | - Jinling Liu
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
| | - Xiaorong Xue
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
| | - Yanjie Lu
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
- Cardiovascular Research Institute, Harbin Medical University
| | - Hongli Shan
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
| | - Baofeng Yang
- Department of Pharmacology, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University
- Cardiovascular Research Institute, Harbin Medical University
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He H, Shi M, Zeng X, Yang X, Yang J, Wu L, Li L. Decreased FKBP12.6 expression and enhanced endothelin receptor signaling associated with arrhymogenesis in myocardial infarction rats. Phytother Res 2008; 22:1115-24. [PMID: 18570278 DOI: 10.1002/ptr.2470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An increased propensity towards cardiac arrhythmias and aggravated heart function is observed in myocardial infarction (MI), the development of which is associated with the calcium handling system in the myocardium. It was hypothesized that the abnormal changes in the MI model may be a consequence of the abnormal expression and function of the RyR2-FKBP12.6 channel complex and that these abnormalities may be related to an over-activated endothelin (ET) system. Salvianolic acid B is expected to suppress life-threatening arrhythmias and to restore the abnormality of the RyR2-FKBP12.6 complex in rats. MI was produced by ligating the coronary artery for 4 weeks. Salvianolic acid B (100 mg/kg/day, p.o. for 4 weeks) was administered to rats 0.5 h before surgery. Measurements of cardiac arrhythmias, cardiac function, calcium transient, cardiac calcium release channel handling proteins and the endothelin system were conducted. The aggravated arrhythmia and compromised cardiac function in MI rats was accompanied by elevated diastolic Ca(2+) levels in the cytosol and a significant down-regulation of expression of RyR2-FKBP12.6. These were closely linked with an over-activated ET pathway in the myocardium. After a 4-week treatment with salvianolic acid B, all abnormalities were reversed significantly. Salvianolic acid B was capable of normalizing FKBP12.6 expression levels and decreasing the propensity towards arrhythmias by attenuating the up-regulated ET pathway.
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Affiliation(s)
- Haibo He
- Institute of Chinese Herb Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, PRC
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23
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Seiva FRF, Ebaid GMX, Castro AVB, Okoshi K, Nascimento A, Rocha KKH, Padovani CR, Cicogna AC, Novelli ELB. Growth hormone and heart failure: oxidative stress and energetic metabolism in rats. Growth Horm IGF Res 2008; 18:275-283. [PMID: 18191600 DOI: 10.1016/j.ghir.2007.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 11/16/2007] [Accepted: 11/19/2007] [Indexed: 10/22/2022]
Abstract
Several evidences point for beneficial effects of growth hormone (GH) in heart failure (HF). Taking into account that HF is related with changes in myocardial oxidative stress and in energy generation from metabolic pathways, it is important to clarify whether GH increase or decrease myocardial oxidative stress and what is its effect on energetic metabolism in HF condition. Thus, this study investigated the effects of two different doses of GH on energetic metabolism and oxidative stress in myocardium of rats with HF. Male Wistar rats (n=25) were submitted to aortic stenosis (AS). The HF was evidenced by tachypnea and echocardiographic criteria around 28 weeks of AS. The rats were then randomly divided into three groups: (HF) with HF, treated with saline (0.9% NaCl); (HF-GH1), treated with 1 mk/kg/day recombinant human growth hormone (rhGH), and (HF-GH2) treated with 2 mg/kg/day rhGH. GH was injected, subcutaneously, daily for 2 weeks. A control group (sham; n=12), with the same age of the others rats was evaluated to confirm data for AS. HF had lower IGF-I (insulin-like growth factor-I) than sham-operated rats, and both GH treatments normalized IGF-I level. HF-GH1 animals had lower lipid hydroperoxide (LH), LH/total antioxidant substances (TAS) and glutathione-reductase than HF. Glutathione peroxidase (GSH-Px), hydroxyacyl coenzyme-A dehydrogenase, lactate dehydrogenase(LDH) were higher in HF-GH1 than in HF. HF-GH2 compared with HF, had increased LH/TAS ratio, as well as decreased oxidized glutathione and LDH activity. Comparing the two GH doses, GSH-Px, superoxide dismutase and LDH were lower in HF-GH2 than in HF-GH1. In conclusion, GH effects were dose-dependent and both tested doses did not aggravate the heart dysfunction. The higher GH dose, 2 mg/kg exerted detrimental effects related to energy metabolism and oxidative stress. The lower dose, 1mg/kg GH exerted beneficial effects enhancing antioxidant defences, reducing oxidative stress and improving energy generation in myocardium of rats with heart failure.
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Affiliation(s)
- F R F Seiva
- Post Graduation Course, Department of Clinical and Cardiology, School of Medicine, São Paulo State University, UNESP, Botucatu, São Paulo, Brazil
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24
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Rabkin R, Awwad I, Chen Y, Ashley EA, Sun D, Sood S, Clusin W, Heidenreich P, Piecha G, Gross ML. Low-dose growth hormone is cardioprotective in uremia. J Am Soc Nephrol 2008; 19:1774-83. [PMID: 18650479 DOI: 10.1681/asn.2007121386] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Growth hormone (GH) is required to maintain normal cardiac structure and function and has a positive effect on cardiac remodeling in experimental and possibly human disease. Cardiac resistance to GH develops in the uremic state, perhaps predisposing to the characteristic cardiomyopathy associated with uremia. It was hypothesized that administration of low-dosage GH may have a salutary effect on the cardiac remodeling process in uremia, but because high levels of GH have adverse cardiac effects, administration of high-dosage GH may worsen uremic cardiomyopathy. In rats with chronic renal failure, quantitative cardiac morphology revealed a decrease in total capillary length and capillary length density and an increase in mean intercapillary distance and fibroblast volume density evident. Low-dosage GH prevented these changes. Collagen and TGF-beta immunostaining, increased in chronic renal failure, were also reduced by GH, suggesting a mechanism for its salutary action. Low-dosage GH also prevented thickening of the carotid artery but did not affect aortic pathology. In contrast, high-dosage GH worsened several of these variables. These results suggest that low-dosage GH may benefit the heart and possibly the carotid arteries in chronic renal failure.
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Affiliation(s)
- Ralph Rabkin
- Department of Medicine, Stanford University and Research Service, Veterans Administration Health Care System, Palo Alto, California 94304, USA.
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25
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Li N, Jia N, Dai DZ, Dai Y. Endothelin receptor antagonist CPU0213 and vitamin E reverse downregulation of FKBP12.6 and SERCA2a: a role of hyperphosphorylation of PKCepsilon. Eur J Pharmacol 2008; 591:211-8. [PMID: 18611397 DOI: 10.1016/j.ejphar.2008.06.080] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 06/18/2008] [Accepted: 06/22/2008] [Indexed: 11/26/2022]
Abstract
Downregulation of FKBP12.6 and sarcoplasmic reticulum Ca(2+) ATPase (SERCA2a) contributes to sudden cardiac death and heart failure. We aimed to test the hypothesis that (i) downregulation of FKBP12.6 and SERCA2a can be taken as molecular markers for drug interventions and (ii) such downregulation is produced by crosstalk between endothelin-reactive oxygen species and beta-adrenoceptors stimulation, mediated by hyperphosphorylation of protein kinase Cvarepsilon (PKCvarepsilon). Rat cardiomyocytes were incubated with isoproterenol (1 microM), endothelin-1 (0.1 microM) or hydrogen peroxide (10 microM) for 18 h, resulting in downregulation of mRNA and protein of FKBP12.6 and SERCA2a, as well as upregulation of PKCvarepsilon mRNA and phosphorylated PKCvarepsilon protein. These changes were reversed by an application of either propranolol (1 microM), endothelin receptor antagonist CPU0213 (1 microM) or vitamin E (1 microM). As indicated by the fluorescent dye Fluo3, diastolic [Ca(2+)](i) in rat ventricular myocytes was increased after incubation with isoproterenol (0.1 microM). The increased [Ca(2+)](i) in diastole was dramatically decreased by CPU0213. Thus, the downregulation of FKBP12.6 and SERCA2a, and hyperphosphorylation of PKCvarepsilon, appear to be related to crosstalk between over-activated endothelin-reactive oxygen species and a beta-adrenoceptor pathway. CPU0213 is beneficial in treating cardiac insufficiency and preventing cardiac arrhythmias possibly by normalizing hyperphosphorylation of PKCvarepsilon and abnormal FKBP12.6 and SERCA2a. The antioxidant activity of vitamin E was sufficient to normalize the levels of FKBP12.6 and SERCA2a and phosphorylation of PKCvarepsilon. Thus by testing with biomarkers FKBP12.6 and SERCA2a, we have shown that the endothelin receptor antagonist CPU0213 and the antioxidant vitamin E may relieve risk of lethal arrhythmias and heart failure by suppressing PKCvarepsilon.
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Affiliation(s)
- Na Li
- Research Division of Pharmacology, China Pharmaceutical University, Nanjing, 210009, China
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26
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Fazio S, Palmieri EA, Affuso F, Cittadini A, Castellano G, Russo T, Ruvolo A, Napoli R, Saccà L. Effects of growth hormone on exercise capacity and cardiopulmonary performance in patients with chronic heart failure. J Clin Endocrinol Metab 2007; 92:4218-23. [PMID: 17698902 DOI: 10.1210/jc.2007-1189] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND Because GH exerted beneficial effects in various experimental models of heart failure, we investigated the effects of GH on physical exercise capacity and cardiopulmonary performance in patients with dilated cardiomyopathy and chronic heart failure (CHF). METHODS Twenty-two patients with CHF (New York Heart Association functional class II-III) underwent spirometry and a symptom-limited, cardiopulmonary exercise testing before and after 3 months of GH (n = 11; seven males; seven idiopathic; 57 +/- 11 yr; 4 IU sc every other day) or placebo (n = 11; eight males; six idiopathic; 54 +/- 10 yr) administration, in a randomized, double-blind trial. Background CHF therapy remained unchanged. RESULTS GH, but not placebo, increased IGF-I serum concentration (from 144 +/- 35 to 293 +/- 58 ng/ml; P < 0.005) and improved New York Heart Association functional class (from 2.4 +/- 0.5 to 1.8 +/- 0.4; P < 0.005), exercise duration (from 831 +/- 273 to 925 +/- 266 sec; P < 0.005), peak power output (from 245 +/- 127 to 280 +/- 132 W; P < 0.05), peak minute ventilation (from 52.5 +/- 16.1 to 61.3 +/- 17.3 liters/min; P < 0.05), peak oxygen consumption (from 19.8 +/- 5.6 to 25.1 +/- 5.6 ml/kg.min; P < 0.005), and anaerobic threshold (from 14.9 +/- 4.8 to 20.0 +/- 4.5 ml/kg.min; P < 0.005) without affecting lung function parameters. Furthermore, the slope of the relationship between minute ventilation and pulmonary carbon dioxide production (ventilatory efficiency) decreased from 34.7 +/- 5.1 to 31.7 +/- 5.3 (P < 0.005), whereas the slope of the relation between percent predicted heart rate reserve used and percent observed metabolic reserve used (chronotropic index) rose from 0.57 +/- 0.20 to 0.69 +/- 0.18 (P < 0.005). CONCLUSION Given the predictive value of physical exercise capacity and cardiopulmonary performance in CHF progression, these data provide additional insights into the mechanisms by which GH may potentially benefit CHF patients.
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Affiliation(s)
- Serafino Fazio
- Department of Internal Medicine, Cardiovascular and Immunological Sciences, University Federico II School of Medicine, 80131 Naples, Italy.
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27
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Foradori CD, Werner SB, Sandau US, Clapp TR, Handa RJ. Activation of the androgen receptor alters the intracellular calcium response to glutamate in primary hippocampal neurons and modulates sarco/endoplasmic reticulum calcium ATPase 2 transcription. Neuroscience 2007; 149:155-64. [PMID: 17870249 DOI: 10.1016/j.neuroscience.2007.06.054] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Revised: 05/28/2007] [Accepted: 06/16/2007] [Indexed: 10/23/2022]
Abstract
Androgens have been shown to have a number of effects on hippocampal function. Although androgen receptors (AR) are found at high levels in hippocampal neurons, the intracellular mechanisms responsible for androgen's actions are unknown. If androgens were capable of altering internal calcium concentration ([Ca(2+)](i)), they could influence a variety of intracellular signaling pathways, maintain neuronal homeostasis and Ca(2+) induced excitotoxicity. In the present study, calcium imaging was used to measure the [Ca(2+)](i) in rat primary hippocampal neurons treated with either the AR agonist dihydrotestosterone (DHT), DHT+flutamide (AR antagonist), flutamide alone, or vehicle for 24 h and subsequently presented with an excitatory glutamate stimulus. In the absence of glutamate stimulation, DHT treatment caused a significant upward shift in baseline [Ca(2+)](i) when compared with neurons from all other groups. Glutamate had a greater effect on [Ca(2+)](i) in DHT-treated neurons and DHT-treated neurons returned to baseline levels significantly faster than all other groups. Cyclopiazonic acid, an inhibitor of sarco/endoplasmic reticulum calcium ATPase (SERCA) had a larger response in DHT-treated neurons compared with controls, suggesting increased Ca(2+) stores in DHT-treated neurons. In all cases the effects of DHT were blocked by treatment with flutamide indicating an AR-mediated mechanism. To determine a possible mechanism by which AR activation could be influencing [Ca(2+)](i), SERCA2 mRNA levels were measured in primary hippocampal neurons. SERCA2 is inserted into the endoplasmic reticulum (ER) membrane and functions to rapidly pump [Ca(2+)](i) into the ER. Following treatment of primary hippocampal neurons with DHT, SERCA2 mRNA was increased, an effect that was blocked in the presence of flutamide. Taken together these results indicate that DHT, working through AR, causes an up-regulation of SERCA2, which increases the sequestering of [Ca(2+)](i) in the endoplasmic reticulum of hippocampal neurons. Such changes may allow the neurons to respond more robustly to a stimulus and recover more quickly following a highly stimulatory challenge.
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Affiliation(s)
- C D Foradori
- Department of Biomedical Sciences, Anatomy and Neurobiology Section, Colorado State University, Fort Collins, CO 80523, USA.
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Huang ZJ, Dai DZ, Li N, Na T, Ji M, Dai Y. Calcium antagonist property of CPU228, a dofetilide derivative, contributes to its low incidence of torsades de pointes in rabbits. Clin Exp Pharmacol Physiol 2007; 34:310-7. [PMID: 17324143 DOI: 10.1111/j.1440-1681.2007.04555.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. Torsades de pointes (TDP) is a severe adverse effect during the clinical use of dofetilide, a selective blocker of the rapid component of the delayed rectifier potassium channel (I(Kr)). The present study was designed to test whether CPU228, a derivative of dofetilide with calcium (Ca(2+)) antagonist properties, could reduce TDP without reducing the blockade of I(Kr). 2. The incidence of TDP in a rabbit model and the effective refractory period (ERP) were measured and compared for dofetilide and CPU228. Suppression of I(Kr) and the L-type Ca(2+) current (I(Ca,L)) and the Ca(2+) transients of isolated cardiomyocytes were investigated by whole-cell patch-clamp and Fluo-3 dye spectrophotometry. 3. The incidence of TDP was greatly reduced by CPU228 relative to dofetilide, occurring in only one of six rabbits compared with five of six rabbits following dofetilide (P < 0.05). In isolated atria, prolongation of ERP by CPU228 was less than that of dofetilide and no reverse frequency dependence was observed. Negative inotropism by CPU228 was significant against positive inotropism by dofetilide. CPU228 inhibited both I(Kr) and I(Ca,L) currents and the IC(50) for I(Ca,L) inhibition was 0.909 micromol/L. At 3 micromol/L, CPU228 significantly suppressed the Ca(2+) transients. 4. CPU228 is able to block I(Ca,L), contributing to decreased TDP, while also blocking I(Kr) activity. By combined blockade of I(Kr) and I(Ca,L), CPU228 shares the property of complex Class III anti-arrhythmic agents.
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Affiliation(s)
- Zhi-Jiang Huang
- Research Division of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
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Minatoya Y, Ito K, Kagaya Y, Asaumi Y, Takeda M, Nakayama M, Takahashi J, Iguchi A, Shirato K, Shimokawa H. Depressed contractile reserve and impaired calcium handling of cardiac myocytes from chronically unloaded hearts are ameliorated with the administration of physiological treatment dose of T3 in rats. Acta Physiol (Oxf) 2007; 189:221-31. [PMID: 17305702 DOI: 10.1111/j.1748-1716.2006.01636.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM Chronic cardiac unloading causes a time-dependent upregulation of phospholamban (PLB) and depression of myocyte contractility in normal rat hearts. As thyroid hormone is known to decrease PLB expression, we examined whether thyroid hormone restores the depressed contractile performance of myocytes from chronically unloaded hearts. METHODS Cardiac unloading was induced by heterotopic heart transplantation in isogenic rats for 5 weeks. Animals were treated with either vehicle or physiological treatment dose of 3,5,3'-triiodo-L-thyronine (T3) that does not cause hyperthyroidism for the last 3 weeks (n=20 each). RESULTS In vehicle-treated animals, myocyte relaxation and [Ca2+]i decay were slower in unloaded hearts than in recipient hearts. Myocyte shortening in response to high [Ca2+]o was also depressed with impaired augmentation of peak-systolic [Ca2+]i in unloaded hearts compared with recipient hearts. In vehicle-treated rats, protein levels of PLB were increased by 136% and the phosphorylation level of PLB at Ser16 were decreased by 32% in unloaded hearts compared with recipient hearts. By contrast, in the T3-treated animals, the slower relaxation, delayed [Ca2+]i decay, and depressed contractile reserve in myocytes from unloaded hearts were all returned to normal levels. Furthermore, in the T3-treated animals, there was no difference either in the PLB protein level or in its Ser16-phosphorylation level between unloaded and recipient hearts. CONCLUSION These results suggest that the treatment with physiological treatment dose of thyroid hormone rescues the impaired myocyte relaxation and depressed contractile reserve at least partially through the restoration of PLB protein levels and its phosphorylation state in chronically unloaded hearts.
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Affiliation(s)
- Y Minatoya
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
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Bocchi E, Moura L, Guimarães G, Conceição Souza GE, Ramires JAF. Beneficial effects of high doses of growth hormone in the introduction and optimization of medical treatment in decompensated congestive heart failure. Int J Cardiol 2006; 110:313-7. [PMID: 16099518 DOI: 10.1016/j.ijcard.2005.06.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Revised: 02/11/2005] [Accepted: 06/24/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND Optimizing oral therapy in patients with unstable decompensated and/or dobutamine-dependent congestive heart failure (CHF) is a challenge. METHODS AND RESULTS We investigated the effects of high doses of recombinant human growth hormone (GH) in 6 patients with cardiac cachexia and unstable decompensated CHF (5 dobutamine-dependent), including its influence in the optimization of oral CHF treatment. Patients received 8 IU of subcutaneous GH per day for median 26 (range 61) days. GH improved the systolic systemic blood pressure (SSBP, in mm Hg) from median 85 (range 34) to 100 (20) (p<.01), and the left ventricular (LV) ejection fraction (in %) from median 23 (range 22) (pretreatment) to 28 (18) (posttreatment) and 38 (28) (later) (p<.007). The NYHA functional class improved from IV to I in 2 patients, from IV to II in 3, and from IV to II-III in one. All patients were discharged from the hospital. It was possible in the hospital to initiate and after discharge to optimize long-term CHF treatment from 37.5 to 50 mg of carvedilol in 5 patients and with higher doses of captopril (from 50 to 150 mg) in all patients. Three patients are alive after 67, 75, and 11 months of follow-up. The remaining 3 patients died from a pulmonary abscess at 9 months, septicemia at 21 months, and progressive heart failure due to unplanned withdrawal of carvedilol at 36 months. CONCLUSION The use of GH in patients with decompensated CHF and cardiac cachexia provided clinical stability without the need for inotropic drugs permitting introduction of nonpreviously tolerated drugs. This could represent a new option for optimizing long-term CHF therapy and discharging hospitalized patients who are dobutamine-dependent.
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Affiliation(s)
- Edimar Bocchi
- Heart Failure Clinics of the Clinical Cardiology Department, Heart Institute of the São Paulo University Medical School, Brazil.
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Cittadini A, Monti MG, Iaccarino G, Di Rella F, Tsichlis PN, Di Gianni A, Strömer H, Sorriento D, Peschle C, Trimarco B, Saccà L, Condorelli G. Adenoviral gene transfer of Akt enhances myocardial contractility and intracellular calcium handling. Gene Ther 2006; 13:8-19. [PMID: 16094411 PMCID: PMC2999753 DOI: 10.1038/sj.gt.3302589] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The serine-threonine kinase Akt/PKB mediates stimuli from different classes of cardiomyocyte receptors, including the growth hormone/insulin like growth factor and the beta-adrenergic receptors. Whereas the growth-promoting and antiapoptotic properties of Akt activation are well established, little is known about the effects of Akt on myocardial contractility, intracellular calcium (Ca(2+)) handling, oxygen consumption, and beta-adrenergic pathway. To this aim, Sprague-Dawley rats were subjected to a wild-type Akt in vivo adenoviral gene transfer using a catheter-based technique combined with aortopulmonary crossclamping. Left ventricular (LV) contractility and intracellular Ca(2+) handling were evaluated in an isolated isovolumic buffer-perfused, aequorin-loaded whole heart preparations 10 days after the surgery. The Ca(2+)-force relationship was obtained under steady-state conditions in tetanized muscles. No significant hypertrophy was detected in adenovirus with wild-type Akt (Ad.Akt) versus controls rats (LV-to-body weight ratio 2.6+/-0.2 versus 2.7+/-0.1 mg/g, controls versus Ad.Akt, P, NS). LV contractility, measured as developed pressure, increased by 41% in Ad.Akt. This was accounted for by both more systolic Ca(2+) available to the contractile machinery (+19% versus controls) and by enhanced myofilament Ca(2+) responsiveness, documented by an increased maximal Ca(2+)-activated pressure (+19% versus controls) and a shift to the left of the Ca(2+)-force relationship. Such increased contractility was paralleled by a slight increase of myocardial oxygen consumption (14%), while titrated dose of dobutamine providing similar inotropic effect augmented oxygen consumption by 39% (P<0.01). Phospholamban, calsequestrin, and ryanodine receptor LV mRNA and protein content were not different among the study groups, while sarcoplasmic reticulum Ca(2+) ATPase protein levels were significantly increased in Ad.Akt rats. beta-Adrenergic receptor density, affinity, kinase-1 levels, and adenylyl cyclase activity were similar in the three animal groups. In conclusion, our results support an important role for Akt/PKB in the regulation of myocardial contractility and mechanoenergetics.
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Affiliation(s)
- A Cittadini
- Department of Clinical Medicine and Cardiovascular Sciences, University 'Federico II', Naples, Italy.
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Groban L, Pailes NA, Bennett CDL, Carter CS, Chappell MC, Kitzman DW, Sonntag WE. Growth hormone replacement attenuates diastolic dysfunction and cardiac angiotensin II expression in senescent rats. J Gerontol A Biol Sci Med Sci 2006; 61:28-35. [PMID: 16456192 DOI: 10.1093/gerona/61.1.28] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We tested the hypothesis that long-term growth hormone (GH) replacement in aged rats would preserve diastolic function and attenuate left ventricular remodeling associated with normal aging. Male Brown Norway x F344 rats were randomized to receive twice daily injections of porcine GH (200 microg/injection, subcutaneous) or saline from 24 to 30 months of age. Adult rats (6- to 9-months old) received saline injections throughout the study. Thirty-month-old, saline-treated rats exhibited low levels of insulin-like growth factor 1 (IGF-1), impaired diastolic left ventricular filling (Doppler), increased cardiac angiotensin II (Ang II), reduced plasma Ang II, and increased cardiac collagen. GH administration in old rats restored IGF-1 and diastolic indices to values comparable to those of adults. These effects were associated with reduced cardiac Ang II and attenuations in cardiac collagen. Age-related decreases in GH and IGF-1 may contribute to the decline in diastolic function of aging, in part through alterations in renin-angiotensin system-mediated ventricular remodeling.
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Affiliation(s)
- Leanne Groban
- Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1009, USA.
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Tivesten A, Isgaard J. Cardiovascular and Respiratory Systems. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2005; 567:149-66. [PMID: 16370139 DOI: 10.1007/0-387-26274-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Asa Tivesten
- Research Center for Endocrinology and Metabolism, Department of Internal Medicine, Sahlgrenska Academy at the University of Göteborg, Sweden
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Demers C, McKelvie RS. Growth hormone therapy in heart failure: a novel therapy worthy of further consideration? Expert Opin Investig Drugs 2005; 14:1009-18. [PMID: 16050793 DOI: 10.1517/13543784.14.8.1009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite the improvements in survival with angiotensin-converting enzyme inhibitors and beta-blockers, the clinical events for patients with heart failure remain elevated. New therapies for heart failure are required to improve the functional capacity, quality of life and prognosis. Growth hormone exerts both direct and indirect effects on cardiac structure and function. Experimental models of heart failure and small studies have demonstrated significant improvements in cardiac function, haemodynamical parameters, functional capacity and quality of life. The results from randomised controlled studies have been mixed with others showing benefit and some that do not. The randomised studies showing benefit consistently used growth hormone every other day. Further studies are needed to assess the potential role of this adjuvant therapy in patients with heart failure.
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Growth hormone-induced reduction of soluble apoptosis mediators is associated with reverse cardiac remodelling and improvement of exercise capacity in patients with idiopathic dilated cardiomyopathy. ACTA ACUST UNITED AC 2005. [DOI: 10.1097/00149831-200504000-00012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Tousoulis D, Charakida M, Stefanadis C. Inflammation and endothelial dysfunction as therapeutic targets in patients with heart failure. Int J Cardiol 2005; 100:347-53. [PMID: 15837076 DOI: 10.1016/j.ijcard.2004.05.030] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 03/16/2004] [Accepted: 05/05/2004] [Indexed: 01/09/2023]
Abstract
Evidence suggests that vascular endothelium plays key role in the regulation of vascular tone, in the process of inflammation and in the thrombotic mechanisms. Recent studies indicate that it is an important component of the pathophysiological mechanisms of heart failure. Heart failure may induce endothelial dysfunction by different mechanisms, such as reduced synthesis and release of nitric oxide (NO), increased degradation of NO or by increased production of endothelin-1. In addition, endothelial dysfunction has been associated with the progression of heart failure. Alterations in neurotransmitters, hormones and also in physiological stimuli are present in heart failure and affect the vascular endothelium. Treatments with beneficial effects on endothelial dysfunction may also improve prognosis in patients with heart failure.
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Affiliation(s)
- Dimitris Tousoulis
- Cardiology Unit, Hippokration Hospital, Athens University Medical School, S. Karagiorga Street 69, 166 75 Glifada Athens, Greece.
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Pemberton CJ, Tokola H, Bagi Z, Koller A, Pöntinen J, Ola A, Vuolteenaho O, Szokodi I, Ruskoaho H. Ghrelin induces vasoconstriction in the rat coronary vasculature without altering cardiac peptide secretion. Am J Physiol Heart Circ Physiol 2004; 287:H1522-9. [PMID: 15142846 DOI: 10.1152/ajpheart.00193.2004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We administered ghrelin, a novel growth hormone-releasing hormone, to isolated perfused rat hearts, coronary arterioles, and cultured neonatal cardiomyocytes to determine its effects on coronary vascular tone, contractility, and natriuretic peptide secretion and gene expression. We also determined cardiac levels of ghrelin and whether the heart is a source of the circulating peptide. Ghrelin dose dependently increased coronary perfusion pressure (44 ± 9%, P < 0.01), constricted isolated coronary arterioles (12 ± 2%, P < 0.05), and significantly enhanced the pressure-induced myogenic tone of arterioles. These effects were blocked by diltiazem, an L-type Ca2+ channel blocker, and bisindolylmaleimide (Bis), a protein kinase C (PKC) inhibitor. Interestingly, coinfusion of ghrelin with diltiazem completely restored myocardial contractile function that was decreased 30 ± 3% ( P < 0.01) by diltiazem alone. In contrast, combination of ghrelin with diltiazem or Bis did not significantly alter atrial natriuretic peptide (ANP) secretion, which was decreased 40% ( P < 0.01) and 50% ( P < 0.05) by these agents alone, respectively. Administration of ghrelin to cultured cardiomyocytes had no effect on ANP or B-type natriuretic peptide secretion or gene expression. Detectable amounts of low-molecular-weight ghrelin were present in cardiac tissue extracts but not in isolated heart perfusate. Thus we provide the first evidence that ghrelin has a coronary vasoconstrictor action that is dependent on Ca2+ and PKC. Furthermore, the data obtained from diltiazem infusion suggest that ghrelin has a role in regulation of contractility when L-type Ca2+ channels are blocked. Finally, the observation that immunoreactive ghrelin is found in cardiac tissue suggests the presence of a local cardiac ghrelin system.
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Affiliation(s)
- Chris J Pemberton
- Christchurch Cardioendocrine Research Group, Christchurch School of Medicine, Christchurch 8001, New Zealand
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Henriques-Coelho T, Correia-Pinto J, Roncon-Albuquerque R, Baptista MJ, Lourenço AP, Oliveira SM, Brandão-Nogueira A, Teles A, Fortunato JM, Leite-Moreira AF. Endogenous production of ghrelin and beneficial effects of its exogenous administration in monocrotaline-induced pulmonary hypertension. Am J Physiol Heart Circ Physiol 2004; 287:H2885-90. [PMID: 15331358 DOI: 10.1152/ajpheart.01122.2003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the endogenous production of ghrelin as well as cardiac and pulmonary vascular effects of its administration in a rat model of monocrotaline (MCT)-induced pulmonary hypertension (PH). Adult Wistar rats randomly received a subcutaneous injection of MCT (60 mg/kg) or an equal volume of vehicle. One week later, animals were randomly assigned to receive a subcutaneous injection of ghrelin (100 mug/kg bid for 2 wk) or saline. Four groups were analyzed: normal rats treated with ghrelin (n=7), normal rats injected with saline (n=7), MCT rats treated with ghrelin (n=9), and MCT rats injected with saline (n=9). At 22-25 days, right (RV) and left ventricular (LV) pressures were measured, heart and lungs were weighted, and samples were collected for histological and molecular analysis. Endogenous production of ghrelin was almost abolished in normal rats treated with ghrelin. In MCT-treated animals, pulmonary expression of ghrelin was preserved, and RV myocardial expression was increased more than 20 times. In these animals, exogenous administration of ghrelin attenuated PH, RV hypertrophy, wall thickening of peripheral pulmonary arteries, and RV diastolic disturbances and ameliorated LV dysfunction, without affecting its endogenous production. In conclusion, decreased tissular expression of ghrelin in healthy animals but not in PH animals suggests a negative feedback in the former that is lost in the latter. A selective increase of ghrelin mRNA levels in the RV of animals with PH might indicate distinct regulation of its cardiac expression. Finally, ghrelin administration attenuated MCT-induced PH, pulmonary vascular remodeling, and RV hypertrophy, indicating that it may modulate PH.
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Jayasankar V, Bish LT, Pirolli TJ, Berry MF, Burdick J, Woo YJ. Local myocardial overexpression of growth hormone attenuates postinfarction remodeling and preserves cardiac function. Ann Thorac Surg 2004; 77:2122-9; discussion 2129. [PMID: 15172279 DOI: 10.1016/j.athoracsur.2003.12.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/10/2003] [Indexed: 11/25/2022]
Abstract
BACKGROUND Ventricular remodeling with chamber dilation and wall thinning is seen in postinfarction heart failure. Growth hormone induces myocardial hypertrophy when oversecreted. We hypothesized that localized myocardial hypertrophy induced by gene transfer of growth hormone could inhibit remodeling and preserve cardiac function after myocardial infarction. METHODS Rats underwent direct intramyocardial injection of adenovirus encoding either human growth hormone (n = 9) or empty null vector as control (n = 9) 3 weeks after ligation of the left anterior descending coronary artery. Analysis of the following was performed 3 weeks after delivery: hemodynamics, ventricular geometry, cardiomyocyte fiber size, and serum growth hormone levels. RESULTS The growth hormone group had significantly better systolic cardiac function as measured by maximum left ventricular pressure (73.6 +/- 6.9 mm Hg versus control 63.7 +/- 7.8 mm Hg, p < 0.05) and maximum dP/dt (2845 +/- 453 mm Hg/s versus 1949 +/- 605 mm Hg/s, p < 0.005), and diastolic function as measured by minimum dP/dt (-2520 +/- 402 mm Hg/s versus -1500 +/- 774 mm Hg/s, p < 0.01). Ventricular geometry was preserved in the growth hormone group (ventricular diameter 12.2 +/- 0.7 mm versus control 13.1 +/- 0.4 mm, p < 0.05; borderzone wall thickness 2.0 +/- 0.2 mm versus 1.5 +/- 0.1 mm, p < 0.001), and was associated with cardiomyocyte hypertrophy (6.09 +/- 0.63 microm versus 4.66 +/- 0.55 microm, p < 0.005). Local myocardial expression of growth hormone was confirmed, whereas serum levels were undetectable after 3 weeks. CONCLUSIONS Local myocardial overexpression of growth hormone after myocardial infarction resulted in cardiomyocyte hypertrophy, attenuated ventricular remodeling, and improved systolic and diastolic cardiac function. The induction of localized myocardial hypertrophy presents a novel therapeutic approach for the treatment of ischemic heart failure.
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Affiliation(s)
- Vasant Jayasankar
- Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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Camp TM, Tyagi SC, Aru GM, Hayden MR, Mehta JL, Tyagi SC. Doxycycline ameliorates ischemic and border-zone remodeling and endothelial dysfunction after myocardial infarction in rats. J Heart Lung Transplant 2004; 23:729-36. [PMID: 15366434 DOI: 10.1016/j.healun.2003.06.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Although matrix metalloproteinase (MMP) activity increases, endothelial function decreases after myocardial infarction (MI). The antibiotic doxycycline inhibits MMP activity in vitro. The role of doxycycline-mediated MMP inhibition in endothelial function is unclear. HYPOTHESIS Doxycycline ameliorates endothelial dysfunction, in part, by inhibiting MMP activity. METHODS We subjected Sprague-Dawley male rats to MI by ligating the left anterior descending arteries. We subjected another group of rats to sham surgery. We administered doxycycline in drinking water (0.67 mg/ml) to both groups 2 days before surgery: the sham group underwent sham surgery and received doxycycline therapy, and the MI group underwent MI and received doxycycline therapy (n = 6 in each group). After 4 weeks, we anesthetized rats and prepared left ventricular rings from infarcted-ischemic (I), non-infarcted near-infarcted (NI), and sham surgery hearts with and without doxycycline treatment. RESULTS The MMP-2 activity increased significantly in I and NI hearts, and we observed a selective increase in MMP-9 activity only in I hearts, when compared with other groups (p < 0.05), measured by zymography. Cardiac inhibitor of metalloproteinase decreased only in I hearts (p < 0.05 vs other groups), measured by Western analysis, and doxycycline treatment reversed this decrease. Contractile response of rings to acetylcholine was attenuated in the I group, suggesting nitric oxide-mediated dysfunction, and was reversed by doxycycline. The response to nitroprusside was attenuated in I hearts and ameliorated by doxycycline, suggesting cardiomyocyte dysfunction. Bradykinin induced relaxation in rings from sham surgery hearts and from NI hearts, but induced paradoxic contraction in rings from I hearts. Treatment with doxycycline reversed the paradoxic contraction. CONCLUSION Results suggest a protective action of doxycycline in the ischemic heart, possibly because of additional pharmacologic actions such as metalloproteinase inhibition.
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Affiliation(s)
- Teresa M Camp
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky 40202, USA
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Abstract
Short-term GH or IGF-I excess provides a model of physiological cardiac growth associated with functional advantage. The physiological nature of cardiac growth is accounted for by the following: (i) the increment in cardiomyocyte size occurs prevalently at expense of the short axis. This is the basis for the concentric pattern of left ventricular (LV) hypertrophy, with consequent fall in LV wall stress and functional improvement; (ii) cardiomyocyte growth is associated with improved contractility and relaxation, and a favourable energetic setting; (iii) the capillary density of the myocardial tissue is not affected; (iv) there is a balanced growth of cardiomyocytes and nonmyocyte elements, which accounts for the lack of interstitial fibrosis; (v) myocardial energetics and mechanics are not perturbed; and (vi) the growth response is not associated with the gene re-programming that characterizes pathologic cardiac hypertrophy and heart failure. Overall, the mechanisms activated by GH or IGF-I appear to be entirely different from those of chronic heart failure. Not to be neglected is also the fact that GH, through its nitric oxide (NO)-releasing action, contributes to the maintenance of normal vascular reactivity and peripheral vascular resistance. This particular kind of interaction of GH with the cardiovascular system accounts for: (i) the lack of cardiac impairment in short-term acromegaly; (ii) the beneficial effects of GH and IGF-I in various models of heart failure; (iii) the protective effect of GH and IGF-I against post-infarction ventricular remodelling; (iv) the reversal of endothelial dysfunction in patients with heart failure treated with GH; and (v) the cardiac abnormalities associated with GH deficiency and their correction after GH therapy. If it is clear that GH and IGF-I exert favourable effects on the heart in the short term, it is equally undeniable that GH excess with time causes pathologic cardiac hypertrophy and, if it is not corrected, eventually leads to cardiac failure. Why then, at one point in time in the natural history of acromegaly, does physiological cardiac growth become maladaptive and translate into heart failure? Before this transition takes places, the acromegalic heart shares very few features with other models of chronic heart failure. None of the mechanisms involved in the progression of heart failure is clearly operative in acromegaly, save for the presence of insulin-resistance and mild alterations of lipoproteins and clot factors. Is this enough to account for the development of heart failure? Probably not. On the other hand, it must be stressed that GH and IGF-I activate several mechanisms that play a protective role against the development of heart failure. These include ventricular unloading, deactivation of neurohormonal components, antiapoptotic effect and enhanced vascular reactivity. Ultimately, all data available concur to hypothesize that acromegalic cardiomyopathy represents a progressive model of cardiac hypertrophy in which the cardiotoxic and pro-remodelling effect is intrinsic to the excessive and unrestrained myocardial growth.
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Affiliation(s)
- Luigi Saccà
- Department of Internal Medicine and Cardiovascular Sciences, University Federico II, Naples, Italy.
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Kanda T, Takahashi T, Itoh T, Kusaka K, Yamakawa J, Kudo S, Takeda T, Tsugawa H, Takekoshi N. Upregulation of Cardiac Ghrelin mRNA in Leptin-Deficient and Leptin Receptor-Deficient Mice with Viral Myocarditis. J Int Med Res 2003; 31:503-8. [PMID: 14708415 DOI: 10.1177/147323000303100606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Expression of cardiac and gastric ghrelin messenger (m) RNA, together with heart and body weights, were measured in leptin-deficient ( ob) and leptin receptor-deficient ( db) mice with heart failure induced by viral myocarditis. Significant elevations in cardiac ghrelin mRNA levels and heart weight were observed in ob and db mice 10 days after viral inoculation compared with baseline values. Expression of gastric ghrelin mRNA was not upregulated in ob and db mice on day 10. The elevated expression of cardiac ghrelin mRNA seems to compensate for the lack of upregulation in gastric ghrelin mRNA.
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Affiliation(s)
- T Kanda
- Department of General Medicine, Kanazawa Medical University, Ishikawa, Japan.
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Omerovic E, Bollano E, Lorentzon M, Walser M, Mattsson-Hultén L, Isgaard J. Growth hormone induces myocardial expression of creatine transporter and decreases plasma levels of IL-1beta in rats during early postinfarct cardiac remodeling. Growth Horm IGF Res 2003; 13:239-245. [PMID: 12932744 DOI: 10.1016/s1096-6374(03)00012-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Growth hormone has been proposed as a potential new therapeutic agent for treatment of myocardial infarction (MI) and congestive heart failure (CHF). The purpose of this study was to evaluate the effects of GH on: (a) myocardial expression of creatine transporter (CreaT) during early postinfarct remodeling, (b) myocardial levels of total creatine (TCr) and adenine pool (TAN) and (c) plasma levels of inflammatory cytokines interleukin-1beta (IL-1beta), tumor-necrosis-factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in rat model of postinfarct cardiac remodeling. Myocardial infarction (MI) was induced by ligation of the left coronary artery in male Sprague-Dawley rats (200-250 g). Three different groups were studied: MI rats treated with GH (n=11) (3 mg/kg/day), MI rats treated with saline (n=10), and sham operated rats (n=7). In the myocardium from GH treated rats the level of mRNA CreaT expression was significantly increased (p<0.01). There was no difference in TCr between the rats with MI and sham-operated rats. Treatment with GH had no effect on TCr. GH had no effect on TAN in left ventricle. All three groups had similar levels of IL-6 and TNF-alpha in plasma. In the rats with MI, treatment with GH normalized the levels of IL-1beta (p<0.05). In conclusion GH increased the expression of CreaT and decreased levels of plasma IL-1beta during postinfarct remodeling in rats. These mechanisms may be responsible for the previously reported beneficial effects of GH on myocardial energy metabolism and preservation of cardiac function in the settings of postinfarct remodeling and CHF.
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Affiliation(s)
- Elmir Omerovic
- Wallenberg Laboratory, Sahlgrenska Academy at Gothenburg University, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
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Dalla Libera L, Ravara B, Volterrani M, Gobbo V, Della Barbera M, Angelini A, Danieli Betto D, Germinario E, Vescovo G. Beneficial effects of GH/IGF-1 on skeletal muscle atrophy and function in experimental heart failure. Am J Physiol Cell Physiol 2003; 286:C138-44. [PMID: 13679302 DOI: 10.1152/ajpcell.00114.2003] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle atrophy is a determinant of exercise capacity in heart failure (CHF). Myocyte apoptosis, triggered by tumor necrosis factor-alpha (TNF-alpha) or its second messenger sphingosine (SPH), is one of the causes of atrophy. Growth hormone (GH) improves hemodynamic and cardiac trophism in several experimental models of CHF, but its effect on skeletal muscle in CHF is not yet clear. We tested the hypothesis that GH can prevent skeletal muscle apoptosis in rats with CHF. CHF was induced by injecting monocrotaline. After 2 wk, 2 groups of rats were treated with GH (0.2 mg.kg(-1).day(-1) and 1.0 mg.kg(-1).day(-1)) subcutaneously. A third group of controls had saline. After 2 additional weeks, rats were killed. Tibialis anterior cross-sectional area, myosin heavy chain (MHC) composition, and a study on myocyte apoptosis and serum levels of TNF-alpha and SPH were carried out. The number of apoptotic nuclei, muscle atrophy, and serum levels of TNF-alpha and SPH were decreased with GH at high but not at low doses compared with CHF rats. Bcl-2 was increased, whereas activated caspases and bax were decreased. The MHC pattern in GH-treated animals was similar to that of controls. Monocrotaline slowed down both contraction and relaxation but did not affect specific tetanic force, whereas absolute force was decreased. GH treatment restored contraction and relaxation to control values and brought muscle mass and absolute twitch and tetanic tension to normal levels. These findings may provide an insight into the therapeutic strategy of GH given to patients with CHF to improve exercise capacity.
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Affiliation(s)
- Luciano Dalla Libera
- Internal Medicine II, Ospedale S. Bortolo, Viale Rodolfi 37, 36100 Vicenza, Italy.
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Nagaya N, Kangawa K. Ghrelin, a novel growth hormone-releasing peptide, in the treatment of chronic heart failure. REGULATORY PEPTIDES 2003; 114:71-7. [PMID: 12832093 DOI: 10.1016/s0167-0115(03)00117-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ghrelin is a novel growth hormone (GH)-releasing peptide, isolated from the stomach, which has been identified as an endogenous ligand for growth-hormone secretagogues receptor (GHS-R). This peptide also causes a positive energy balance by stimulating food intake and inducing adiposity through growth hormone-independent mechanisms. In addition, ghrelin has some cardiovascular effects, as indicated by the presence of its receptor in blood vessels and the cardiac ventricles. In vitro, ghrelin inhibits apoptosis of cardiomyocytes and endothelial cells. In humans, infusion of ghrelin decreases systemic vascular resistance and increases cardiac output in patients with heart failure. Repeated administration of ghrelin improves cardiac structure and function and attenuates the development of cardiac cachexia in rats with heart failure. These results suggest that ghrelin has cardiovascular effects and regulates energy metabolism through GH-dependent and -independent mechanisms. Thus, administration of ghrelin may be a new therapeutic strategy for the treatment of severe chronic heart failure (CHF).
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Affiliation(s)
- Noritoshi Nagaya
- Department of Internal Medicine, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
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Saraiva RM, Chedid NGB, Quintero H CC, Díaz G LE, Masuda MO. Impaired beta-adrenergic response and decreased L-type calcium current of hypertrophied left ventricular myocytes in postinfarction heart failure. Braz J Med Biol Res 2003; 36:635-48. [PMID: 12715084 DOI: 10.1590/s0100-879x2003000500012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Infarct-induced heart failure is usually associated with cardiac hypertrophy and decreased -adrenergic responsiveness. However, conflicting results have been reported concerning the density of L-type calcium current (I Ca(L)), and the mechanisms underlying the decreased -adrenergic inotropic response. We determined I Ca(L) density, cytoplasmic calcium ([Ca2+]i) transients, and the effects of -adrenergic stimulation (isoproterenol) in a model of postinfarction heart failure in rats. Left ventricular myocytes were obtained by enzymatic digestion 8-10 weeks after infarction. Electrophysiological recordings were obtained using the patch-clamp technique. [Ca2+]i transients were investigated via fura-2 fluorescence. -Adrenergic receptor density was determined by [ H]-dihydroalprenolol binding to left ventricle homogenates. Postinfarction myocytes showed a significant 25% reduction in mean I Ca(L) density (5.7 0.28 vs 7.6 0.32 pA/pF) and a 19% reduction in mean peak [Ca2+]i transients (0.13 0.007 vs 0.16 0.009) compared to sham myocytes. The isoproterenol-stimulated increase in I Ca(L) was significantly smaller in postinfarction myocytes (Emax: 63.6 4.3 vs 123.3 0.9% in sham myocytes), but EC50 was not altered. The isoproterenol-stimulated peak amplitude of [Ca2+]i transients was also blunted in postinfarction myocytes. Adenylate cyclase activation through forskolin produced similar I Ca(L) increases in both groups. -Adrenergic receptor density was significantly reduced in homogenates from infarcted hearts (Bmax: 93.89 20.22 vs 271.5 31.43 fmol/mg protein in sham myocytes), while Kd values were similar. We conclude that postinfarction myocytes from large infarcts display reduced I Ca(L) density and peak [Ca2+]i transients. The response to -adrenergic stimulation was also reduced and was probably related to -adrenergic receptor down-regulation and not to changes in adenylate cyclase activity.
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MESH Headings
- Adenylyl Cyclases/drug effects
- Adrenergic beta-Agonists/pharmacology
- Animals
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Colforsin/pharmacology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Electrophysiologic Techniques, Cardiac
- Female
- Heart Failure/etiology
- Heart Failure/metabolism
- Hypertrophy, Left Ventricular/pathology
- Isoproterenol/pharmacology
- Male
- Myocardial Infarction/complications
- Myocardial Infarction/metabolism
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Rats
- Rats, Wistar
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/metabolism
- Time Factors
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Affiliation(s)
- R M Saraiva
- Departamento de Cardiologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
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Demers C, McKelvie RS. Growth hormone therapy in heart failure: where are we now? CONGESTIVE HEART FAILURE (GREENWICH, CONN.) 2003; 9:84-90. [PMID: 12671339 DOI: 10.1111/j.1527-5299.2003.00283.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Despite improvement in survival with angiotensin-converting enzyme inhibitors and beta blockers, clinical events for patients with heart failure remain elevated. New therapies for heart failure are needed to improve functional capacity, quality of life, and prognosis. Growth hormone exerts direct and indirect effects on cardiac structure and function. Experimental models of heart failure and small studies have demonstrated significant improvements in cardiac function, hemodynamic parameters, functional capacity, and quality of life. Despite the lack of benefit demonstrated in small, short-term, randomized clinical trials, further studies are needed to assess the potential role of this adjuvant therapy in heart failure patients.
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Affiliation(s)
- Catherine Demers
- Hamilton Health Sciences (HHS), HHS-General Division, Hamilton, Ontario, L8L 2X2 Canada
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Acevedo M, Corbalán R, Chamorro G, Jalil J, Nazzal C, Campusano C, Castro P. Administration of growth hormone to patients with advanced cardiac heart failure: effects upon left ventricular function, exercise capacity, and neurohormonal status. Int J Cardiol 2003; 87:185-91. [PMID: 12559539 DOI: 10.1016/s0167-5273(02)00249-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Experimental and clinical studies have shown that the administration of recombinant human growth hormone can improve deteriorated left ventricular function and hemodynamics in patients with heart failure. Herein, we compared the effects of growth hormone versus placebo upon resting left ventricular ejection fraction, exercise capacity and neurohormonal status in patients with advanced heart failure. Nineteen patients with advanced cardiac heart failure (ejection fraction <30%) were studied at baseline and after 8 weeks of treatment with growth hormone (0.03 U/kg per day) or placebo. Primary end points were resting left ventricular ejection fraction, peak oxygen consumption and neurohormonal status, including plasma norepinephrine levels and insulin like growth factor-1 and its binding protein-3. Results are presented as median and interquartile ranges. Patients receiving growth hormone had a significant increase in insulin growth factor-1 plasma levels (median difference growth hormone=83 ng/ml [57-170] versus placebo=-6 ng/ml [-23-6], P<0.05) and its binding protein-3. However, no significant increase in left ventricular ejection fraction after growth hormone treatment (ejection fraction pre=16% [13-18] and post=17% [14-27]) was noticed when compared to placebo (ejection fraction pre=20% [15-24] and post=20% [15-26]). Also, no significant effect of growth hormone treatment was seen on peak oxygen consumption or norepinephrine plasma levels. Although the administration of growth hormone to patients with advanced cardiac heart failure was associated with a significant increase in insulin growth factor-1, there were no significant changes in ejection fraction, exercise capacity and/or neurohormonal status.
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Affiliation(s)
- Mónica Acevedo
- Department of Cardiovascular Diseases, Endocrinology and Metabolic Diseases, Catholic University of Chile, Marcoleta 367, Santiago, Chile
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Jin H, Yang R, Lu H, Ogasawara AK, Li W, Ryan A, Peale F, Paoni NF. Effects of early treatment with growth hormone on infarct size, survival, and cardiac gene expression after acute myocardial infarction. Growth Horm IGF Res 2002; 12:208-215. [PMID: 12175653 DOI: 10.1016/s1096-6374(02)00042-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE This study examined the effects of growth hormone (GH) on infarct size, survival, and cardiac gene expression in rats with acute myocardial infarction. DESIGN Animals randomly received sc injection of either saline vehicle (n = 98) or GH (2mg/kg/day, n = 105) for 14 days commencing the day of left coronary artery ligation. Infarct size was determined by morphometric analysis at the time of death or at 52 weeks post-surgery. Gene expression was analyzed by real-time RT-PCR after 2-week treatment. RESULTS GH decreased infarct size by 18% (P < 0.01) and increased survival by 36% at 52 weeks. GH also significantly reduced cardiac expression of atrial natriuretic factor, beta-myosin heavy chain, alpha-smooth muscle actin, collagen I, collagen III, fibronectin, and pro-inflammatory cytokines. CONCLUSIONS Treatment with GH for 2 weeks beginning on the day of myocardial infarction produced beneficial effects that were associated with reductions in cardiac gene expression symptomatic of pathological remodeling.
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Affiliation(s)
- Hongkui Jin
- Department of Cardiovascular Research, Genentech, Inc., South San Francisco, CA 94080, USA.
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MacAndrew JT, Ellery SS, Parry MA, Pan LC, Black SC. Efficacy of a growth hormone-releasing peptide mimetic in cardiac ischemia/reperfusion injury. Eur J Pharmacol 2001; 432:195-202. [PMID: 11740956 DOI: 10.1016/s0014-2999(01)01475-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The cardioprotective efficacy of the pyrazolinone-piperidine dipeptide growth hormone secretagogue (GHS) CP-424,391 was studied in an in vivo rabbit model of ischemia and reperfusion. CP-424,391 was administered at 25 mg/kg p.o. x 7 days. Ischemia was induced by left coronary artery occlusion for 30 min, after which the heart was reperfused for 2 h. At the end of reperfusion, animals were euthanized and the infarct size was determined. The area at risk of infarct was not different between the control (45.8+/-3.7%, n=6) and CP-424,391-treated groups (36.9+/-4.3%, n=11). The infarct size of the control animals was 49.5+/-7.1% and was significantly (P<0.05) lower in the CP-424,391-treated group (infarct size=17.3+/-3.0). There was a trend, albeit not significant, for the left ventricular function to recover to a greater extent in CP-424,391-treated rabbits. Thus, the treatment of rabbits for 7 days with CP-424,391 was cardioprotective against ischemia/reperfusion injury.
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Affiliation(s)
- J T MacAndrew
- Cardiovascular and Metabolic Diseases, Pfizer Global Research and Development, Eastern Point Road, Groton, CT 06340, USA
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