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Participation of Central Muscarinic Receptors on the Nervous Form of Chagas Disease in Mice Infected via Intracerebroventricular with Colombian Trypanosoma cruzi Strain. Pathogens 2021; 10:pathogens10020121. [PMID: 33503848 PMCID: PMC7922850 DOI: 10.3390/pathogens10020121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/09/2021] [Accepted: 01/14/2021] [Indexed: 11/30/2022] Open
Abstract
Acute chagasic encephalitis is a clinically severe central nervous system (CNS) manifestation. However, the knowledge of the nervous form of Chagas disease is incomplete. The role of the muscarinic acetylcholine receptor (mAChR) on mice behavior and brain lesions induced by Trypanosoma cruzi (Colombian strain) was herein investigated in mice treated with the mAChR agonist and antagonist (carbachol and atropine), respectively. Immunosuppressed or non-immunosuppressed mice were intracerebroventricularly (icv) or intraperitoneally (ip) infected. All groups were evaluated 15 d.p.i. (days post infection). Intraperitoneally infected animals had subpatent parasitemia. Patent parasitemia occurred only in icv infected mice. The blockade of mAChR increased the parasitemia, parasitism and lesions compared to its activation. Infected not treated (INT ip) mice did not present meningitis and encephalitis, regardless of immunosuppression. INT icv brains presented higher cellularity, discrete signs of cellular degeneration, frequent presence of parasites and focal meningitis. The immunosuppressed atropine + icv mice presented increased intracellular parasitism associated with degenerative parenchymal changes, while carbachol + icv mice presented discrete meningitis, preservation of the cortex and absence of relevant parasitism. Cholinergic receptor blockage increased impairment of coordination vs. receptor activation. Muscarinic cholinergic pathway seems to be involved in immune mediated cell invasion events while its blockade favored infection evolution, brain lesions, and behavioral alterations.
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Martí‐Carvajal AJ, Kwong JSW. Pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. Cochrane Database Syst Rev 2016; 7:CD009077. [PMID: 27388039 PMCID: PMC6457883 DOI: 10.1002/14651858.cd009077.pub3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in people with Chagas disease. This is an update of a Cochrane review published in 2012. OBJECTIVES To assess the clinical benefits and harms of current pharmacological interventions for treating heart failure in people with Chagas cardiomyopathy. SEARCH METHODS We updated the searches in the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2016, Issue 1), MEDLINE (Ovid; 1946 to to February Week 1 2016), EMBASE (Ovid; 1947 to 2016 Week 07), LILACS (1982 to 15 February 2016), and Web of Science (Thomson Reuters; 1970 to 15 February 2016). We checked the reference lists of included papers. We applied no language restrictions. SELECTION CRITERIA We included randomised clinical trials (RCTs) that assessed the effects of pharmacological interventions to treat heart failure in adult patients (18 years or older) with symptomatic heart failure (New York Heart Association classes II to IV), regardless of the left ventricular ejection fraction stage (reduced or preserved), with Chagas cardiomyopathy. We did not apply limits to the length of follow-up. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time-to-heart decompensation, disease-free period (at 30, 60, and 90 days), and adverse events. DATA COLLECTION AND ANALYSIS Two authors independently performed study selection, 'Risk of bias' assessment and data extraction. We estimated relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I² statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data. We developed 'Summary of findings' (SoF) tables and used GRADE methodology to assess the quality of the evidence. MAIN RESULTS In this update, we identified one new trial. Therefore, this version includes three trials (108 participants). Two trials compared carvedilol against placebo and another assessed rosuvastatin versus placebo. All trials had a high risk of bias.Meta-analysis of two trials showed a lower proportion of all-cause mortality in the carvedilol groups compared with the placebo groups (RR 0.69; 95% CI 0.12 to 3.88, I² = 0%; 69 participants; very low-quality evidence). Neither of the trials reported on cardiovascular mortality, time-to-heart decompensation, or disease-free periods.One trial (30 participants) found no difference in hospital readmissions (RR 1.00; 95% CI 0.31 to 3.28; very low-quality of evidence) or reported adverse events (RR 0.92; 95% CI 0.67 to 1.27; very low-quality of evidence) between the carvedilol and placebo groups.There was very low-quality evidence from two trials of inconclusive effects on quality of life (QoL) between the carvedilol and placebo groups. One trial (30 participants) assessed QoL with the Minnesota Living With Heart Failure Questionnaire (21 items; item scores range from 0 to 5; a lower MLHFQ score is better). The MD was -14.74; 95% CI -24.75 to -4.73. The other trial (39 participants) measured QoL with the Medical Outcomes Study 36-item short-form health survey (SF-36; item scores range from 0 to 100; higher SF-36 score is better). Data were not provided.One trial (39 participants) assessed the effect of rosuvastatin versus placebo. The trial did not report on any primary outcomes or adverse events. There was very low-quality evidence of uncertain effects on QoL (no data were provided). AUTHORS' CONCLUSIONS This first update of our review found very low-quality evidence for the effects of either carvedilol or rosuvastatin, compared with placebo, for treating heart failure in people with Chagas disease. The three included trials were underpowered and had a high risk of bias. There were no conclusive data to support or reject the use of either carvedilol or rosuvastatin for treating Chagas cardiomyopathy. Unless randomised clinical trials provide evidence of a treatment effect, and the trade-off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending or administering either carvedilol or rosuvastatin to treat heart failure in people with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in people with Chagas disease remains unknown.
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Affiliation(s)
| | - Joey SW Kwong
- West China Hospital, Sichuan UniversityChinese Evidence‐Based Medicine CenterNo. 37, Guo Xue XiangChengduSichuanChina610041
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Neves BCD, Bacilio ML, Berrueta L, Salmen S, Peterson DL, Donis JH, Nuñez TJ, Davila DF. Muscarinic antibodies and heart rate responses to dynamic exercise and to the Valsalva maneuver in chronic chagasic patients. Rev Inst Med Trop Sao Paulo 2013; 55:31-7. [PMID: 23328723 DOI: 10.1590/s0036-46652013000100006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 08/14/2012] [Indexed: 11/22/2022] Open
Abstract
We have studied the cardiac chronotropic responses to the Valsalva maneuver and to dynamic exercise of twenty chronic chagasic patients with normal left ventricular function and no segmental wall abnormalities by two-dimensional echocardiogram. The absolute increase in heart rate of the patients (Δ = 21.5 ± 10 bpm, M±SD) during the maneuver was significantly diminished when compared to controls (Δ = 31.30 ± 70, M±SD, p = 0.03). The minimum heart rate (58.24 ± 8.90 vs. 62.80 ± 10, p = 0.68) and the absolute decrease in heart rate at the end of the maneuver (Δ = 38.30 ± 13 vs. Δ = 31.47 ± 17, p = 0.10) were not different from controls. The initial heart rate acceleration during dynamic exercise (Δ = 12 ± 7.55 vs. Δ = 19 ± 7.27, M±SD, p = 0.01) was also diminished, but the heart rate recovery during the first ten seconds was more prominent in the sero-positive patients (Median: 14, Interquartile range: (9.75-17.50 vs. 5(0-8.75, p = 0.001). The serum levels of muscarinic cardiac auto-antibodies were significantly higher in the chagasic patients (Median: 34.58, Interquartile Range: 17-46.5, Optical Density) than in controls (Median: 0, Interquartile Range: 0-22.25, p = 0.001) and correlated significantly and directly (r = 0.68, p = 0.002) with early heart rate recovery during dynamic exercise. The results of this investigation indirectly suggest that, the cardiac muscarinic auto-antibodies may have positive agonist effects on parasympathetic heart rate control of chagasic patients.
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Affiliation(s)
- Barbara C das Neves
- Instituto de Investigaciones Cardiovasculares, Universidad de Los Andes, Mérida, Venezuela
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Bonfante-Cabarcas R, López Hincapié E, Jiménez Hernández E, Fonseca Zambrano R, Ferrer Mancini L, Durand Mena M, Rodríguez-Bonfante C. Electrophysiological and pharmacological evaluation of the nicotinic cholinergic system in chagasic rats. BMC Pharmacol Toxicol 2013; 14:2. [PMID: 23294487 PMCID: PMC3576276 DOI: 10.1186/2050-6511-14-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 12/21/2012] [Indexed: 12/19/2022] Open
Abstract
Background Two theories attempt to explain the changes observed in the nicotinic acetylcholine receptors (nAChRs) in chagasic cardiomyopathy. The neurogenic theory proposes that receptor changes are due to loss of intracardiac ganglia parasympathetic neurons. The immunogenic theory proposes that the nAChRs changes are the result of autoantibodies against these receptors. Both theories agreed that nAChRs functional expression could be impaired in Chagas disease. Methods We evaluated nAChRs functional integrity in 54 Sprague Dawley rats, divided in two groups: healthy and chronic chagasic rats. Rats were subjected to electrocardiographic studies in the whole animal under pentobarbital anesthesia, by isolation and stimulation of vagus nerves and in isolated beating hearts (Langendorff’s preparation). Results Nicotine, 10 μM, induced a significant bradycardia in both groups. However, rats that had previously received reserpine did not respond to nicotine stimulation. β-adrenergic stimulation, followed by nicotine treatment, induced tachycardia in chagasic rats; while inducing bradycardia in healthy rats. Bilateral vagus nerve stimulation induced a significantly higher level of bradycardia in healthy rats, compared to chagasic rats; physostigmine potentiated the bradycardic response to vagal stimulation in both experimental groups. Electric stimulation (e.g., ≥ 2 Hz), in the presence of physostigmine, produced a comparable vagal response in both groups. In isolated beating-heart preparations 1 μM nicotine induced sustained bradycardia in healthy hearts while inducing tachycardia in chagasic hearts. Higher nicotine doses (e.g.,10 – 100 uM) promoted the characteristic biphasic response (i.e., bradycardia followed by tachycardia) in both groups. 10 nM DHβE antagonized the effect of 10 μM nicotine, unmasking the cholinergic bradycardic effect in healthy rats only. 1 nM α-BGT alone induced bradycardia in healthy hearts but antagonized the 10 μM nicotine-induced tachycardia in chagasic rats. In healthy but not in chagasic hearts, 10 μM nicotine shortened PQ and PR interval, an effect counteracted by MA, DHβE and αBGT Conclusion Our results suggest that cholinergic function is impaired in chronic Chagas disease in rats, a phenomena that could be related to alteration on the nAChR expression.
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Affiliation(s)
- Rafael Bonfante-Cabarcas
- Biochemistry Research Units, Health Sciences School, Universidad Centro Occidental Lisandro Alvarado, Barquisimeto, Lara, Venezuela.
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Hidalgo R, Martí-Carvajal AJ, Kwong JSW, Simancas-Racines D, Nicola S. Pharmacological interventions for treating heart failure in patients with chagas cardiomyopathy. Cochrane Database Syst Rev 2012; 11:CD009077. [PMID: 23152267 DOI: 10.1002/14651858.cd009077.pub2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in patients with Chagas disease. OBJECTIVES To assess the benefits and harms of current pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) Issue 1, 2011, MEDLINE (Ovid), EMBASE (Ovid), LILACS and ISI Web of Science to April 2011. We checked the reference lists of included papers. No language restrictions were applied. SELECTION CRITERIA We included randomized clinical trials assessing the effects of pharmacological interventions for treating heart failure in adult patients (≥18 years) with symptomatic heart failure (New York Heart Association class II to IV), irrespective of the left ventricular ejection fraction stage, reduced or preserved, with Chagas cardiomyopathy. No limits were applied with respect to the follow-up duration. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time to heart decompensation and disease-free period (at 30, 60 and 90 days), and adverse events. DATA COLLECTION AND ANALYSIS Two authors independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) and the respective 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data. MAIN RESULTS We included two randomized clinical trials involving 69 participants. Both trials compared carvedilol against placebo, and had a high risk of bias. Carvedilol compared with placebo did not significantly affect all-cause mortality (2/34 (5.88%) versus 3/35 (5.87%); pooled RR 0.69, 95% CI 0.12 to 3.88, I(2) = 0%). None of the trials reported on cardiovascular mortality, time to heart decompensation or disease-free period. Evidence on the adverse effects of carvedilol is inconclusive. AUTHORS' CONCLUSIONS This Cochrane review has found a lack of evidence on the effects of carvedilol for treating heart failure in patients with Chagas disease. The two included trials were underpowered and had a high risk of bias. There are no conclusive data to support the use of carvedilol for treating Chagas cardiomyopathy. Unless randomized clinical trials provide evidence of a treatment effect, and the trade off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending and administering carvedilol for treating heart failure in patients with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in patients with Chagas disease is unknown.
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Affiliation(s)
- Ricardo Hidalgo
- Facultad de Ciencias de la Salud Eugenio Espejo, Universidad Tecnológica Equinoccial, Quito, Ecuador
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Herda LR, Felix SB, Boege F. Drug-like actions of autoantibodies against receptors of the autonomous nervous system and their impact on human heart function. Br J Pharmacol 2012; 166:847-57. [PMID: 22220626 PMCID: PMC3412294 DOI: 10.1111/j.1476-5381.2012.01828.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Antibodies against cholinergic and adrenergic receptors (adrenoceptors) are frequent in serum of patients with chronic heart failure. Their prevalence is associated with Chagas' disease, idiopathic dilated cardiomyopathy (DCM), and ischaemic heart disease. Among the epitopes targeted are first and second extracellular loops of the β-adrenergic (β-adrenoceptor) and M2 muscarinic receptor. β1-adrenoceptor autoantibodies affect radioligand binding and cardiomyocyte function similar to agonists. Corresponding rodent immunizations induce symptoms compatible with chronic heart failure that are reversible upon removal of the antibodies, transferable via the serum and abrogated by adrenergic antagonists. In DCM patients, prevalence and stimulatory efficacy of β1-adrenoceptor autoantibodies are correlated to the decline in cardiac function, ventricular arrhythmia and higher incidence of cardiac death. In conclusion, such autoantibodies seem to cause or promote chronic human left ventricular dysfunction by acting on their receptor targets in a drug-like fashion. However, the pharmacology of this interaction is poorly understood. It is unclear how the autoantibodies trigger changes in receptor activity and second messenger coupling and how that is related to the pathogenesis and severity of the associated diseases. Here, we summarize the available evidence regarding these issues and discuss these findings in the light of recent knowledge about the conformational activation of the human β2-adrenoceptor and the properties of bona fide cardiopathogenic autoantibodies derived from immune-adsorption therapy of DCM patients. These considerations might contribute to the conception of therapy regimen aimed at counteracting or neutralizing cardiopathogenic receptor autoantibodies.
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Affiliation(s)
- L R Herda
- Department of Internal Medicine B, University of Greifswald, Greifswald, Germany
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Dávila DF, Donis JH, Arata de Bellabarba G, Villarroel V, Sanchez F, Berrueta L, Salmen S, Das Neves B. Cardiac autonomic control mechanisms in the pathogenesis of chagas' heart disease. Interdiscip Perspect Infect Dis 2012; 2012:980739. [PMID: 23091486 PMCID: PMC3467757 DOI: 10.1155/2012/980739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/27/2012] [Indexed: 11/17/2022] Open
Abstract
Primary abnormalities of the autonomic nervous system had been postulated as the pathogenic mechanisms of myocardial damage, in patients with Chagas disease. However, recent investigations indicate that these abnormalities are secondary and amenable to treatment with beta-adrenergic blockers. Moreover, muscarinic cardiac autoantibodies appear to enhance parasympathetic activity on the sinus node. Therefore, the purpose of this paper is to analyze how knowledge on Chagas' disease evolved from being initially considered as a primary cardioneuromyopathy to the current status of a congestive cardiomyopathy of parasitic origin.
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Affiliation(s)
- Diego F. Dávila
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Jose H. Donis
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Gabriela Arata de Bellabarba
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Vanesa Villarroel
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Francisco Sanchez
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Lisbeth Berrueta
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Siham Salmen
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Barbara Das Neves
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
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Martí-Carvajal AJ, Hidalgo R, Kwong J. Pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2011. [DOI: 10.1002/14651858.cd009077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Peraza-Cruces K, Gutiérrez-Guédez L, Castañeda Perozo D, Lankford CR, Rodríguez-Bonfante C, Bonfante-Cabarcas R. Trypanosoma cruzi infection induces up-regulation of cardiac muscarinic acetylcholine receptors in vivo and in vitro. Braz J Med Biol Res 2009; 41:796-803. [PMID: 18820770 DOI: 10.1590/s0100-879x2008000900009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Accepted: 08/27/2008] [Indexed: 11/22/2022] Open
Abstract
The pathogenesis of chagasic cardiomyopathy is not completely understood, but it has been correlated with parasympathetic denervation (neurogenic theory) and inflammatory activity (immunogenic theory) that could affect heart muscarinic acetylcholine receptor (mAChR) expression. In order to further understand whether neurogenic and/or immunogenic alterations are related to changes in mAChR expression, we studied two models of Trypanosoma cruzi infection: 1) in 3-week-old male Sprague Dawley rats chronically infected with T. cruzi and 2) isolated primary cardiomyocytes co-cultured with T. cruzi and peripheral blood mononuclear cells (PBMC). Using [3H]-quinuclidinylbenzilate ([3H]-QNB) binding assays, we evaluated mAChR expression in homogenates from selected cardiac regions, PBMC, and cultured cardiomyocytes. We also determined in vitro protein expression and pro-inflammatory cytokine expression in serum and cell culture medium by ELISA. Our results showed that: 1) mAChR were significantly (P < 0.05) up-regulated in right ventricular myocardium (means +/- SEM; control: 58.69 +/- 5.54, N = 29; Chagas: 72.29 +/- 5.79 fmol/mg, N = 34) and PBMC (control: 12.88 +/- 2.45, N = 18; Chagas: 20.22 +/- 1.82 fmol/mg, N = 19), as well as in cardiomyocyte transmembranes cultured with either PBMC/T. cruzi co-cultures (control: 24.33 +/- 3.83; Chagas: 43.62 +/- 5.08 fmol/mg, N = 7 for both) or their conditioned medium (control: 37.84 +/- 3.84, N = 4; Chagas: 54.38 +/- 6.28 fmol/mg, N = 20); 2) [(3)H]-leucine uptake was increased in cardiomyocytes co-cultured with PBMC/T. cruzi-conditioned medium (Chagas: 21,030 +/- 2321; control 10,940 +/- 2385 dpm, N = 7 for both; P < 0.05); 3) plasma IL-6 was increased in chagasic rats, IL-1beta, was increased in both plasma of chagasic rats and in the culture medium, and TNF-alpha level was decreased in the culture medium. In conclusion, our results suggest that cytokines are involved in the up-regulation of mAChR in chronic Chagas disease.
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Affiliation(s)
- K Peraza-Cruces
- Unidad de Bioquímica, Universidad Centro Occidental "Lisandro Alvarado", Barquisimeto, Venezuela
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Chagas disease: Impaired vagal modulation has been demonstrated, enhanced parasympathetic activity remains to be proved. Int J Cardiol 2008. [DOI: 10.1016/j.ijcard.2007.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Ribeiro ALP, Giménez LED, Hernández CCQ, de Carvalho ACC, Teixeira MM, Guedes VC, Barros MVL, Lombardi F, Rocha MODC. Early occurrence of anti-muscarinic autoantibodies and abnormal vagal modulation in Chagas disease. Int J Cardiol 2007; 117:59-63. [PMID: 16859766 DOI: 10.1016/j.ijcard.2006.04.053] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 04/06/2006] [Accepted: 04/28/2006] [Indexed: 02/08/2023]
Abstract
BACKGROUND Autoimmunity and dysautonomia are established features of Chagas disease (ChD) that could be related to its pathogenesis. Our objective was to assess heart rate variability (HRV) and levels of anti-M2 receptors autoantibodies in ChD patients with and without left ventricular (LV) dysfunction, in order to establish if these abnormalities occur early and concomitantly in the course of the illness. METHODS ChD patients (n=75) and healthy controls (n=14) underwent a standardized protocol including Doppler echocardiogram, Holter monitoring, HRV analysis, and measurement of anti-M2 receptors autoantibodies (ELISA). ChD patients were divided accordingly by the absence (group 1, n=45) or presence (group 2, n=30) of LV dysfunction, defined as reduced LV ejection fraction (<55%) or regional wall motion abnormalities (including ventricular aneurysm). RESULTS Both ChD groups displayed increased optical density values of anti-M2 cholinergic autoantibodies (Median (IQR): control=1.98(0.51); ChD 1=2.76(0.97); ChD 2=2.72(1.34), p<.001) and reduced HF power of spectral analysis of HRV when compared to controls (Median (IQR) in ms2: control=1087(2284); ChD 1=286(763); ChD 2=285(763), p<.001). M2 levels were significantly correlated with HF power values (r=-0.32, p=0.023), but not with LV ejection fraction. CONCLUSIONS Anti-muscarinic autoantibodies and abnormal vagal modulation occur early in ChD patients, independently of the presence of LV dysfunction. Levels of antibodies against M2 muscarinic receptors were significantly and negatively correlated with HRV index HF power, suggesting an inhibitory effect of autoantibodies in vagal function.
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Affiliation(s)
- Antonio Luiz Pinho Ribeiro
- Postgraduate Course of Tropical Medicine, School of Medicine, Av. Alfredo Balena, 190-Campus Saúde, 30130-100. Belo Horizonte, Brazil.
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Dávila DF, Santiago JJ, Odreman WA. Vagal dysfunction and the pathogenesis of chronic Chagas disease. Int J Cardiol 2005; 100:337-9. [PMID: 15823646 DOI: 10.1016/j.ijcard.2004.11.006] [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: 11/01/2004] [Accepted: 11/13/2004] [Indexed: 11/22/2022]
Abstract
Vagal dysfunction is thought to be an early, primary and specific abnormality of chronic Chagas disease. However, chagasic patients with unequivocal evidence of heart disease, can have normal or abnormal vagal control of heart rate. A common explanation for these apparently discordant and contradictory results is proposed.
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