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Baghcheghi Y, Beheshti F, Hosseini M, Gowhari-Shabgah A, Ali-Hassanzadeh M, Hedayati-Moghadam M. Cardiovascular protective effects of PPARγ agonists in hypothyroid rats: protection against oxidative stress. Clin Exp Hypertens 2022; 44:539-547. [PMID: 35722928 DOI: 10.1080/10641963.2022.2079669] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hypothyroidism disturbs redox homeostasis and takes part in cardiovascular system dysfunction. Considering antioxidant and cardio-protective effects of PPAR-γ agonists including pioglitazone (POG) and rosiglitazone (RSG), the present study was aimed to determine the effect of POG or RSG on oxidants and antioxidants indexes in the heart and aorta tissues of Propylthiouracil (PTU)-induced hypothyroid rats. MATERIALS AND METHODS The animals were divided into six groups: (1) Control; (2) propylthiouracil (PTU), (3) PTU-POG 10, (4) PTU-POG 20, (5) PTU-RSG 2, and (6) PTU-RSG 4. Hypothyroidism was induced in rats by giving 0.05% propylthiouracil (PTU) in drinking water for 42 days. The rats of PTU-POG 10 and PTU-POG 20 groups received 10 and 20 mg/kg POG, respectively, besides PTU, and the rats of PTU-RSG 2 and PTU-RSG 4 groups received 2 and 4 mg/kg RSG, respectively, besides PTU. The animals were sacrificed, and the serum of the rats was collected to measure thyroxine level. The heart and aorta tissues were also removed for the measurement of biochemical oxidative stress markers. RESULTS Hypothyroidism was induced by PTU administration, which was indicated by lower serum thyroxine levels. Hypothyroidism also was accompanied by a decrease of catalase (CAT), superoxide dismutase (SOD) activities, and thiol concentration in the heart and aorta tissues while increased level of malondialdehyde (MDA). Interestingly, administration of POG or RSG dramatically reduced oxidative damage in the heart and aorta, as reflected by a decrease in MDA and increased activities of SOD, CAT, and thiol content. CONCLUSION The results of this study showed that administration of POG or RSG decreased oxidative damage in the heart and aorta tissues induced by hypothyroidism in rats.
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Affiliation(s)
- Yousef Baghcheghi
- Student Research Committee Jiroft University of Medical Sciences, Jiroft, Iran
| | - Farimah Beheshti
- Neuroscience Research Center, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran.,Department of Physiology, School of Paramedical Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Mahmoud Hosseini
- Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Mohammad Ali-Hassanzadeh
- Department of Immunology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
| | - Mahdiyeh Hedayati-Moghadam
- Student Research Committee Jiroft University of Medical Sciences, Jiroft, Iran.,Department of Physiology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
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Beheshti F, Hosseini M, Hashemzehi M, Hadipanah MR, Mahmoudabady M. The Cardioprotective Effects of Aminoguanidine on Lipopolysaccharide Induced Inflammation in Rats. Cardiovasc Toxicol 2020; 20:474-81. [DOI: 10.1007/s12012-020-09570-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Hoefig CS, Jacobi SF, Warner A, Harder L, Schanze N, Vennström B, Mittag J. 3-Iodothyroacetic acid lacks thermoregulatory and cardiovascular effects in vivo. Br J Pharmacol 2015; 172:3426-33. [PMID: 25765843 DOI: 10.1111/bph.13131] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 01/20/2015] [Accepted: 03/10/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE 3-Iodothyronamine (3-T1 AM) is an endogenous thyroid hormone derivative reported to induce strong hypothermia and bradycardia within minutes upon injection in rodents. Although 3-T1 AM is rapidly converted to several other metabolites in vivo, these strong pharmacological responses were solely attributed to 3-T1 AM, leaving potential contributions of downstream products untested. We therefore examined the cardiometabolic effects of 3-iodothyroacetic acid (TA1 ), the main degradation product of 3-T1 AM. EXPERIMENTAL APPROACH We used a sensitive implantable radiotelemetry system in C57/Bl6J mice to study the effects of TA1 on body temperature and heart rate, as well as other metabolic parameters. KEY RESULTS Interestingly, despite using pharmacological TA1 doses, we observed no effects on heart rate or body temperature after a single TA1 injection (50 mg·kg(-1) , i.p.) compared to sham-injected controls. Repeated administration of TA1 (5 mg·kg(-1) , i.p. for 7 days) likewise did not alter body weight, food and water intake, heart rate, blood pressure, brown adipose tissue (BAT) thermogenesis or body temperature. Moreover, mRNA expression of tissue specific genes in heart, kidney, liver, BAT and lung was also not altered by TA1 compared to sham-injected controls. CONCLUSIONS AND IMPLICATIONS Our data therefore conclusively demonstrate that TA1 does not contribute to the cardiovascular or thermoregulatory effects observed after 3-T1 AM administration in mice, suggesting that the oxidative deamination constitutes an important deactivation mechanism for 3-T1 AM with possible implications for cardiovascular and thermoregulatory functions.
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Affiliation(s)
- Carolin S Hoefig
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Simon F Jacobi
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Amy Warner
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Lisbeth Harder
- Center of Brain Behavior and Metabolism CBBM/Medizinische Klinik I, University of Lübeck, Lübeck, Germany
| | - Nancy Schanze
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Björn Vennström
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jens Mittag
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.,Center of Brain Behavior and Metabolism CBBM/Medizinische Klinik I, University of Lübeck, Lübeck, Germany
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Abstract
Dietary selenium (Se) is an essential micronutrient that exerts its biological effects through its incorporation into selenoproteins. This family of proteins contains several antioxidant enzymes such as the glutathione peroxidases, redox-regulating enzymes such as thioredoxin reductases, a methionine sulfoxide reductase, and others. In this review, we summarise the current understanding of the roles these selenoproteins play in protecting the cardiovascular system from different types of stress including ischaemia-reperfusion, homocysteine dysregulation, myocardial hypertrophy, doxirubicin toxicity, Keshan disease, and others.
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Affiliation(s)
| | - Peter R Hoffmann
- Peter R. Hoffmann, University of Hawaii, John A. Burns School of Medicine, 651 Ilalo Street, Honolulu, HI 96813, USA, Fax: +1 808 692 1968, E-mail:
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Abstract
Over the past few decades, obesity and its related metabolic disorders have increased at an epidemic rate in the developed and developing world. New signals and factors involved in the modulation of energy balance and metabolism are continuously being discovered, providing potential novel drug targets for the treatment of metabolic disease. A parallel strategy is to better understand how hormonal signals, with an already established role in energy metabolism, work, and how manipulation of the pathways involved may lead to amelioration of metabolic dysfunction. The thyroid hormones belong to the latter category, with dysregulation of the thyroid axis leading to marked alterations in energy balance. The potential of thyroid hormones in the treatment of obesity has been known for decades, but their therapeutic use has been hampered because of side-effects. Data gleaned over the past few years, however, have uncovered new features at the mechanisms of action involved in thyroid hormones. Sophisticated neurobiological approaches have allowed the identification of specific energy sensors, such as AMP-activated protein kinase and mechanistic target of rapamycin, acting in specific groups of hypothalamic neurons, mediating many of the effects of thyroid hormones on food intake, energy expenditure, glucose, lipid metabolism, and cardiovascular function. More extensive knowledge about these molecular mechanisms will be of great relevance for the treatment of obesity and metabolic syndrome.
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Affiliation(s)
- Noelia Martínez-Sánchez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain.
| | - Clara V Alvarez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain.
| | - Johan Fernø
- Department of Clinical Science, K. G. Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway.
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain.
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain.
| | - Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain.
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Duntas LH, Chiovato L. Cardiovascular Risk in Patients with Subclinical Hypothyroidism. Eur Endocrinol 2014; 10:157-160. [PMID: 29872482 DOI: 10.17925/ee.2014.10.02.157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/04/2014] [Indexed: 12/26/2022]
Abstract
Subclinical hypothyroidism (SCH) has been associated with increased cardiovascular mortality due to adverse effects mainly on lipids and blood pressure (BP). There is evidence that SCH, especially in patients with thyroid-stimulating hormone (TSH) >10mU/l, may increase cardiovascular risk. Some uncertainty exists regarding the association of SCH with BP; however, that the coexistence of SCH with BP and hypercholesterolaemia has a negative cardiovascular impact is beyond doubt. Insulin resistance, by modulating various risk factors including coagulation, may potentially increase cardiovascular risk. Periodic health examinations including screening has been advised in patients >35 years of age, while treatment with thyroxine should be tailored to each patient.
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Affiliation(s)
- L H Duntas
- Professor, Unit of Endocrinology, Metabolism and Diabetes, Evgenidion Hospital, University of Athens, Greece
| | - Luca Chiovato
- Professor, Unit of Internal Medicine and Endocrinology, Fondazione Salvatore Maugeri Istituto di Ricovero e Cura a Carattere Scientifico, University of Pavia, Italy
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Szkudlarek AC, Aldenucci B, Miyagui NI, Silva IK, Moraes RN, Ramos HE, Fogaça RTH. Short-term thyroid hormone excess affects the heart but does not affect adrenal activity in rats. Arq Bras Cardiol 2014; 102:270-8. [PMID: 24676225 PMCID: PMC3987310 DOI: 10.5935/abc.20140014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 09/19/2013] [Indexed: 12/26/2022] Open
Abstract
Background Hyperthyroidism (Hy) exerts a broad range of influences on a variety of
physiological parameters. Its disruptive effect on cardiovascular system is one of
its most remarkable impacts. Moreover, Hy has been clinically associated with
stress - induced hyperactivation of the hypothalamic-pituitary-adrenal axis. Objective Evaluate the impact of short-term Hy on cardiac performance and adrenal activity
of rats. Methods Induction of Hy in Wistar rats through injections of T3 (150
µg/kg) for 10 days (hyperthyroid group - HG) or vehicle (control
group). The cardiovascular performance was evaluated by: echocardiography (ECHO);
heart weight/body weight (mg/gr) ratio; contractility of isolated papillary
muscles (IPM) and direct measurement of blood pressures. Adrenal activity was
evaluated by adrenal weight/body weight (mg/gr) ratio and 24-hour fecal
corticosterone (FC) levels on the, 5th and 10th days of T3
treatment. Results In HG, the ECHO showed reduction of the End Systolic and End Diastolic Volumes,
Ejection, Total Diastolic and Isovolumic Relaxation Times, Diastolic and Systolic
Areas and E/A ratio. Heart Rate, Ejection Fraction and Cardiac Output increased.
The heart weight/body weight ratio was higher. Similarly, in IPM, the maximum rate
of force decay during relaxation was higher in all extracellular calcium
concentrations. Systolic blood pressure (SBP) levels were higher. (p ≤ 0.05). On
the other hand, there was no difference in the adrenal weight/body weight ratio or
in the 24-hour FC levels. Conclusions Hy induces positive inotropic, chronotropic and lusitropic effects on the heart by
direct effects of T3 and increases SBP. Those alterations are not correlated with
changes in the adrenal activity.
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Karmaniolou I, Pantos C, Orfanos N, Mylonas A, Theodoraki K, Staikou C, Stergiou E, Kostopanagiotou G, Smyrniotis V, Arkadopoulos N. Impact of thyroid hormone administration on fluid requirements and hepatic injury markers in hemorrhagic shock due to liver trauma. J INVEST SURG 2013; 26:305-11. [PMID: 23978248 DOI: 10.3109/08941939.2013.797055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION The aim of the present study was to evaluate the effect of triiodothyronine (T3) administration in a porcine model of hemorrhagic shock due to liver surgery, in terms of hemodynamic stability, acid-base status, and hepatic injury markers. MATERIALS AND METHODS Hemorrhagic shock was induced in swine by left lobe liver resection and allowed bleeding to a mean arterial pressure of 35-40 mmHg for 40 min. Animals were randomly assigned into a sham group (n = 5), a fluid-resuscitated group (n = 7), and a fluid plus T3-resuscitated group (n = 7). T3 was given by continuous intravenous infusion from the beginning of the experiment. After the 40 min of shock animals were resuscitated with the aim of restoring mean arterial pressure (±10% from baseline). Resuscitation lasted for 1 hr and then swine were followed for another 460 min (total 6 hr). Blood loss, hamodynamic parameters, fluids administered, acid-base status, and liver enzymes were measured. RESULTS Blood loss was similar in both groups. Animals treated with T3 required less fluids than swine resuscitated with crystalloids and colloids only (N/S 0.9%: 1071 ± 189 ml vs. 2429 ± 535 ml, Voluven 6%: 550 ± 96 ml vs. 1000 ± 289 ml, p < .05), plus they were less acidotic at the end of the observing period (7.38 ± 0.08 vs. 7.26 ± 0.12, p < .05). Tachycardia was not associated with T3 administration. Hepatic enzymes did not exhibit differences between groups. CONCLUSION Our study demonstrates the beneficial impact of T3 administration during controlled hemorrhagic shock and resuscitation. Animals resuscitated with T3 necessitate less amounts of fluids to maintain hemodynamic stability and acid-base status. Moreover, T3 administration does not seem to aggravate blood loss or harm the hepatic tissue.
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Affiliation(s)
- Iosifina Karmaniolou
- 1 2nd Department of Anesthesia, Attikon Hospital, University of Athens, Medical School, Chaidari, Greece
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Roef GL, Taes YE, Kaufman JM, Van Daele CM, De Buyzere ML, Gillebert TC, Rietzschel ER. Thyroid hormone levels within reference range are associated with heart rate, cardiac structure, and function in middle-aged men and women. Thyroid 2013; 23:947-54. [PMID: 23339744 PMCID: PMC3752520 DOI: 10.1089/thy.2012.0471] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Triiodothyronine (T3) has many effects on the heart, and marked changes in cardiac function and structure occur in patients with (subclinical) thyroid disease. We investigated whether between-subject variation in thyroid hormone levels within the euthyroid range is also associated with heart rate and echocardiographic heart function and structure. METHODS Subjects were selected from the Asklepios study (n=2524), a population-representative random sample of patients aged between 35 and 55 years, free from overt cardiovascular disease at baseline. Analyses were restricted to 2078 subjects (1013 women and 1065 men), not using antihypertensive or thyroid medication nor having antithyroperoxidase antibody levels above clinical cut-off or thyrotropin (TSH) levels outside the reference range. All subjects were phenotyped in-depth and underwent comprehensive echocardiography, including diastolic evaluation. Thyroid function parameters were determined by automated electrochemiluminescence. RESULTS Heart rate was robustly positively associated with (quartiles of) free T3 (FT3) and T3, both in subjects with TSH levels within reference (0.27-4.2 μU/L) and in narrow TSH range (0.5-2.5 μU/L; p<0.0001). FT3 and T3 were negatively associated with left ventricular (LV) end-diastolic volume but positively associated with relative wall thickness. Total T3 (TT3) was associated with enhanced ventricular contraction (as assessed by tissue Doppler imaging). Free thyroxine, FT3, and TT3 were positively associated with late ventricular filling, and TT3 was associated with early ventricular filling. CONCLUSION We have demonstrated a strong positive association between thyroid hormone levels within the euthyroid range and heart rate, and more subtle effects on cardiac function and structure. More specifically, we suggest a smaller LV cavity size (with increased relative wall thickness), an enhanced atrial and ventricular contraction, and LV relaxation with higher circulating thyroid hormones. These results illustrate that variation in thyroid hormone levels, even within the reference range, exerts effects on the heart.
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Affiliation(s)
- Greet L Roef
- Department of Endocrinology, Ghent University Hospital, Ghent, Belgium.
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10
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Abstract
Increased or reduced action of thyroid hormone on certain molecular pathways in the heart and vasculature causes relevant cardiovascular derangements. It is well established that hyperthyroidism induces a hyperdynamic cardiovascular state, which is associated with a faster heart rate, enhanced left ventricular systolic and diastolic function whereas hypothyroidism is characterized by the opposite changes. Hyperthyroidism and hypothyroidism represent opposite clinical conditions, albeit not mirror images. Recent experimental and clinical studies have suggested the involvement of ROS tissue damage under altered thyroid status. Altered-thyroid state-linked changes in heart modify their susceptibility to oxidants and the extent of the oxidative damage they suffer following oxidative challenge. Chronic increase in the cellular levels of ROS can lead to a catastrophic cycle of DNA damage, mitochondrial dysfunction, further ROS generation and cellular injury. Thus, these cellular events might play an important role in the development and progression of myocardial remodeling and heart failure in altered thyroid states (hypo- and hyper-thyroidism). The present review aims at elucidating the various signaling pathways mediated via ROS and their modulation under altered thyroid state and the possibility of antioxidant therapy.
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Affiliation(s)
- Pallavi Mishra
- Department of Zoology, Utkal University, Odisha, Bhubaneswar 751004, India
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Ferrer T, Arín RM, Casis E, Torres-Jacome J, Sanchez-Chapula JA, Casis O. Mechanisms responsible for the altered cardiac repolarization dispersion in experimental hypothyroidism. Acta Physiol (Oxf) 2012; 204:502-12. [PMID: 21933354 DOI: 10.1111/j.1748-1716.2011.02364.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To identify the causes for the inhomogeneity of ventricular repolarization and increased QT dispersion in hypothyroid mice. METHODS We studied the effects of 5-propyl-2-thiouracil-induced hypothyroidism on the ECG, action potential (AP) and current density of the repolarizing potassium currents I(to,fast), I(to,slow), I(K,slow) and I(ss) in enzymatically isolated myocytes from three different regions of mouse heart: right ventricle (RV), epicardium of the left ventricle (Epi-LV) and interventricular septum. K(+) currents were recorded with the patch-clamp technique. Membranes from isolated ventricular myocytes were extracted by centrifugation. Kv4.2, Kv4.3, KChIP and Na/Ca exchanger proteins were visualized by Western blot. RESULTS The frequency or conduction velocity was not changed by hypothyroidism, but QTc was prolonged. Neither resting membrane potential nor AP amplitude was modified. The action potential duration (APD)(90) increased in the RV and Epi-LV, but not in the septum. Hypothyroid status has no effect either on I(to,slow), I(k,slow) or I(ss) in any of the regions analysed. However, I(to,fast) was significantly reduced in the Epi-LV and in the RV, whereas it was not altered in cells from the septum. Western blot analysis reveals a reduction in Kv4.2 and Kv4.3 protein levels in both the Epi-LV and the RV and an increase in Na/Ca exchanger. CONCLUSION From these results we suggest that the regional differences in APD lengthening, and thus in repolarization inhomogeneity, induced by experimental hypothyroidism are at least partially explained by the uneven decrease in I(to,fast) and the differences in the relative contribution of the depolarization-activated outward currents to the repolarization process.
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Affiliation(s)
- T Ferrer
- Unidad de Investigacion "Carlos Mendez" del Centro Universitario de Investigaciones Biomedicas, Universidad de Colima, Mexico
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Hoffmann FW, Hashimoto AS, Lee BC, Rose AH, Shohet RV, Hoffmann PR. Specific antioxidant selenoproteins are induced in the heart during hypertrophy. Arch Biochem Biophys 2011; 512:38-44. [PMID: 21621505 DOI: 10.1016/j.abb.2011.05.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/06/2011] [Accepted: 05/15/2011] [Indexed: 12/21/2022]
Abstract
Selenium (Se) is thought to confer cardioprotective effects through the actions of antioxidant selenoprotein enzymes that directly limit levels of ROS such as hydrogen peroxide (H(2)O(2)) or that reverse oxidative damage to lipids and proteins. To determine how the selenoproteome responds to myocardial hypertrophy, two mouse models were employed: triidothyronine (T3)- or isoproterenol (ISO)-treatment. After 7days of T3- and ISO-treatment, cardiac stress was demonstrated by increased H(2)O(2) and caspase-3 activity. Neither treatment produced significant increases in phospholipid peroxidation or TUNEL-positive cells, suggesting that antioxidant systems were protecting the cardiomyocytes from damage. Many selenoprotein mRNAs were induced by T3- and ISO-treatment, with levels of methionine sulfoxide reductase 1 (MsrB1, also called SelR) mRNA showing the largest increases. MsrB enzymatic activity was also elevated in both models of cardiac stress, while glutathione peroxidase (GPx) activity and thioredoxin reductase (Trxrd) activity were moderately and nonsignificantly increased, respectively. Western blot assays revealed a marked increase in MsrB1 and moderate increases in GPx3, GPx4, and Trxrd1, particularly in T3-treated hearts. Thus, the main response of the selenoproteome during hypertrophy does not involve increased GPx1, but increased GPx3 for reducing extracellular H(2)O(2) and increased GPx4, Trxrd1, and MsrB1 for minimizing intracellular oxidative damage.
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Affiliation(s)
- FuKun W Hoffmann
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA
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Mittag J, Davis B, Vujovic M, Arner A, Vennström B. Adaptations of the autonomous nervous system controlling heart rate are impaired by a mutant thyroid hormone receptor-alpha1. Endocrinology 2010; 151:2388-95. [PMID: 20228172 DOI: 10.1210/en.2009-1201] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thyroid hormone has profound direct effects on cardiac function, but the hormonal interactions with the autonomic control of heart rate are unclear. Because thyroid hormone receptor (TR)-alpha1 has been implicated in the autonomic control of brown adipose energy metabolism, it might also play an important role in the central autonomic control of heart rate. Thus, we aimed to analyze the role of TRalpha1 signaling in the autonomic control of heart rate using an implantable radio telemetry system. We identified that mice expressing the mutant TRalpha1R384C (TRalpha1+m mice) displayed a mild bradycardia, which becomes more pronounced during night activity or on stress and is accompanied by a reduced expression of nucleotide-gated potassium channel 2 mRNA in the heart. Pharmacological blockage with scopolamine and the beta-adrenergic receptor antagonist timolol revealed that the autonomic control of cardiac activity was similar to that in wild-type mice at room temperature. However, at thermoneutrality, in which the regulation of heart rate switches from sympathetic to parasympathetic in wild-type mice, TRalpha1+m mice maintained sympathetic stimulation and failed to activate parasympathetic signaling. Our findings demonstrate a novel role for TRalpha1 in the adaptation of cardiac activity by the autonomic nervous system and suggest that human patients with a similar mutation in TRalpha1 might exhibit a deficit in cardiac adaptation to stress or physical activity and an increased sensitivity to beta-blockers.
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Affiliation(s)
- Jens Mittag
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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Agelaki MG, Pantos C, Korantzopoulos P, Tsalikakis DG, Baltogiannis GG, Fotopoulos A, Kolettis TM. Comparative antiarrhythmic efficacy of amiodarone and dronedarone during acute myocardial infarction in rats. Eur J Pharmacol 2007; 564:150-7. [PMID: 17391666 DOI: 10.1016/j.ejphar.2007.02.052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 02/20/2007] [Accepted: 02/26/2007] [Indexed: 01/21/2023]
Abstract
The effects of dronedarone, a non-iodinated derivative of amiodarone, on ventricular tachycardia and ventricular fibrillation post-myocardial infarction are not well established. Fifty-five Wistar rats were randomly allocated to a 2-week oral treatment with either vehicle (n=18), amiodarone (30 mg/kg, n=20), or dronedarone (30 mg/kg, n=17). After acute coronary artery ligation, a single-lead electrocardiogram was continuously recorded for 24 h and episodes of ventricular tachycardia/fibrillation as well as mortality rates were analysed. Monophasic action potential recordings were obtained from the left ventricular epicardium at baseline and 24 h post-myocardial infarction. Thyroid hormones and catecholamines were measured using radioimmunoassay. Thyroid function was similar in the 3 groups. Compared to controls, amiodarone and dronedarone equally decreased the number of ventricular tachycardia/fibrillation episodes by approximately 75%. Both agents prevented the increase in monophasic action potential duration and in beat-to-beat variation. Norepinephrine levels were lower only after amiodarone treatment. Despite the observed antiarrhythmic effect, total mortality did not differ between groups (38.8% in controls, 30.0% in the amiodarone group and 58.8% in the dronedarone group), because of excess bradyarrhythmic mortality in both drug groups that reached significance in the dronedarone group. Dronedarone and amiodarone display similar antiarrhythmic efficacy post-myocardial infarction, partly by preventing repolarization inhomogeneity. However, dronedarone increases bradyarrhythmic mortality possibly secondary to its negative inotropic effects.
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Affiliation(s)
- Maria G Agelaki
- Department of Cardiology, University of Ioannina Medical School, 45110 Ioannina, Greece
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Pantos C, Mourouzis I, Saranteas T, Paizis I, Xinaris C, Malliopoulou V, Cokkinos DV. Thyroid hormone receptors alpha1 and beta1 are downregulated in the post-infarcted rat heart: consequences on the response to ischaemia-reperfusion. Basic Res Cardiol 2005; 100:422-32. [PMID: 16133716 DOI: 10.1007/s00395-005-0545-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Revised: 06/09/2005] [Accepted: 06/13/2005] [Indexed: 12/18/2022]
Abstract
There is accumulating evidence that thyroid hormone metabolism is altered after myocardial infarction (AMI) but its physiological relevance remains largely unknown. The present study investigated the possible role of thyroid hormone signaling in the response of the post-infarcted heart to ischaemia-reperfusion. Wistar rats were subjected to left coronary artery ligation (AMI), or sham operation (SHAM). After 8 weeks, hearts from AMI and SHAM rats were perfused in Langendorff mode and subjected to 20 min of zero-flow global ischaemia (I) and 45 min of reperfusion (R); AMI(I/R), n = 7 and SHAM(I/R), n = 7. Basal left ventricular pressure (LVDP), +dp/dt, and -dp/dt were significantly reduced. Left ventricular weight of the viable myocardium was increased by 14% in the AMI as compared to SHAM hearts, P < 0.05. T(3) and T(4) plasma levels in nM were 1.83 (0.08) and 53.3 (2.9) for SHAM and 1.76 (0.06) and 59.4 (5.2) for AMI rats, respectively, P > 0.05. TRalpha1 and TRbeta1 expression levels were 1.3- and 1.8-fold less in AMI than in SHAM hearts, P < 0.05. Furthermore, SERCA and NHE1 expression levels were 2.1- and 1.8-fold less in AMI than in SHAM, P < 0.05. PKCepsilon was 1.35-fold more in AMI compared to SHAM, P < 0.05. Myocardial glycogen content (in micromol/g) was 7.8 (1.2) in AMI as compared to 4.4 (0.5) for SHAM hearts, P < 0.05. After I/R, left ventricular end-diastolic pressure at 45 min of R (LVEDP45 in mmHg) was 20.3 (3.2) for AMI(I/R) vs 50.6 (4.8) mmHg for SHAM(I/R), P < 0.05. LDH release per gram of tissue was 251 (103) for AMI(I/R) and 762 (74) for SHAM(I/R), P < 0.05. In conclusion, TRalpha1 and TRbeta1 are downregulated after myocardial infarction and this was associated with altered expression of thyroid hormone responsive genes and increased tolerance of the post-infarcted heart to ischaemia-reperfusion injury.
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Affiliation(s)
- C Pantos
- Department of Pharmacology, University of Athens, 75 Mikras Asias Ave., 11527 Goudi, Athens, Greece.
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Hu LW, Liberti EA, Barreto-Chaves MLM. Myocardial ultrastructure in cardiac hypertrophy induced by thyroid hormone?an acute study in rats. Virchows Arch 2005; 446:265-9. [PMID: 15668802 DOI: 10.1007/s00428-004-1175-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 11/08/2004] [Indexed: 10/25/2022]
Abstract
The early responses of the myocardium ultrastructure under thyroid dysfunction conditions, hemodynamic parameters, cardiac hypertrophy and ultrastructural evaluations were performed in hypothyroid and hyperthyroid rats submitted to different doses [T4-25 and T4-100; 0.025 mg and 0.1 mg kg(-1) body weight (BW).per day, respectively)]. All groups were treated for 7 days. The animals were sacrificed, the hearts were excised and weighed and the left ventricle tissue samples were processed for transmission election microscopy. Systolic blood pressure (SBP) was not altered by administration of T4. An increased heart rate and ratio of heart weight to body weight (HW/BW) were found in the hyperthyroid rats. However, the SBP and HW/BW decreased significantly in hypothyroid rats. No significant ultrastructural alterations were detected when the hypothyroid and T4-25 groups were compared with the control group. Alterations of cardiomyocytes nuclei of these groups were also not detected. Notably, disorganization of intercellular junctions was observed in many cardiomyocytes of T4-100 group. The present results indicate that in the early stages of hyperthyroidism, the cardiac hypertrophy development was mainly due to direct effects of thyroid hormone. Despite cardiac hypertrophy development, there is no ultrastructural evidence of myocardial degeneration.
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Affiliation(s)
- Li Wen Hu
- Laboratory of Cellular Biology and Functional Anatomy, Department of Anatomy, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes 2415, Cidade Universitária, 05508-900 São Paulo, Brazil
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Ferreira PJ, L'Abbate C, Abrahamsohn PA, Gouveia CA, Moriscot AS. Temporal and topographic ultrastructural alterations of rat heart myofibrils caused by thyroid hormone. Microsc Res Tech 2003; 62:451-9. [PMID: 14601151 DOI: 10.1002/jemt.10415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In order to further our understanding regarding the temporal and topographic ultrastructural aspects of the myocardium under thyrotoxicosis, thyroxine (T4; 25 and 100 microg/100 g bw) was administered to young rats 24 hours after birth until 15 days. The animals were then sacrificed, the hearts excised and weighed, and the ventricle tissue samples were then processed for confocal and transmission electron microscopy. At 48/72 hours and 1 week after initiation of T4 treatment with 100 microg/100 g bw, numerous lamellar bodies (probably formed by phospholipids) progressively accumulated in the heart. These bodies were observed in the cytosol, inside mitochondria and in the extracellular matrix. At 2 weeks of T4 treatment with 100 microg/100 g bw, lamellar bodies were virtually absent. Changes in cell shape, disorganization of intercellular junctions, and substantial myofibrillar disarray were observed in many cardiomyocytes. A gradient of myofibrillar disarray, which increased in abundance and intensity from the endocardium to the epicardium, was also observed. Immunocytochemical staining for desmin showed that the arrangement of this protein was disorganized in many cells of T4-treated rats as compared with normal ones, confirming ultrastructural data. The predominant appearance of myofibrillar disarray, associated with disorganization of cytoskeletal proteins in the deep myocardium, may be due to higher mechanical wall stress and consequent higher metabolic demand. Alternatively, differential sensitivity of cardiomyocytes to thyroid hormone in different areas is also a possibility.
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Affiliation(s)
- Paula Juliana Ferreira
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, 05508-900, Sao Paulo, SP, Brazil
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Affiliation(s)
- Mark A. Sussman
- From The Children’s Hospital and Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio
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