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Jordão MR, Pessoa FG, Fonseca KC, Zanoni F, Salemi VM, Souza LE, Ribeiro ON, Fernandes F, Irigoyen MC, Moreira LFP, Mady C, Ramires FJA. Effects of sympathectomy on myocardium remodeling and function. Clinics (Sao Paulo) 2021; 76:e1958. [PMID: 33503174 PMCID: PMC7798118 DOI: 10.6061/clinics/2021/e1958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/08/2020] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVES To evaluate the effects of sympathectomy on the myocardium in an experimental model. METHODS The study evaluated three groups of male Wistar rats: control (CT; n=15), left unilateral sympathectomy (UNI; n=15), and bilateral sympathectomy (BIL; n=31). Sympathectomy was performed by injection of absolute alcohol into the space of the spinous process of the C7 vertebra. After 6 weeks, we assessed the chronotropic properties at rest and stress, cardiovascular autonomic modulation, myocardial and peripheral catecholamines, and beta-adrenergic receptors in the myocardium. The treadmill test consisted of an escalated protocol with a velocity increment until the maximal velocity tolerated by the animal was reached. RESULTS The bilateral group had higher levels of peripheral catecholamines, and consequently, a higher heart rate (HR) and blood pressure levels. This suggests that the activation of a compensatory pathway in this group may have deleterious effects. The BIL group had basal tachycardia immediately before the exercise test and increased tachycardia at peak exercise (p<0.01); the blood pressure had the same pattern (p=0.0365). The variables related to autonomic modulation were not significantly different between groups, with the exception of the high frequency (HF) variable, which showed significant differences in CT vs UNI. There was no significant difference in beta receptor expression between groups. There was a higher concentration of peripheral norepinephrine in the BIL group (p=0.0001), and no significant difference in myocardial norepinephrine (p=0.09). CONCLUSION These findings suggest that an extra cardiac compensatory pathway increases the sympathetic tonus and maintains a higher HR and higher levels of peripheral catecholamines in the procedure groups. The increase in HF activity can be interpreted as an attempt to increase the parasympathetic tonus to balance the greater sympathetic activity.
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Affiliation(s)
- Maurício Rodrigues Jordão
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Fernanda G. Pessoa
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Keila C.B. Fonseca
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Fernando Zanoni
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Vera M.C. Salemi
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Leandro E. Souza
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Orlando N. Ribeiro
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Fábio Fernandes
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Maria Claudia Irigoyen
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Luiz Felipe P. Moreira
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Charles Mady
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Felix Jose Alvarez Ramires
- Instituto do Coracao (InCor), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- *Corresponding author. E-mail:
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Fonseca K, Pessoa F, Mady C, Hotta V, Ribeiro ON, Fernandes F, Ianni B, Saldiva P, Ramires F. IMPACT OF AIR POLLUTION ON MYOCARDIAL REMODELING IN CHAGA'S DISEASE. J Am Coll Cardiol 2019. [DOI: 10.1016/s0735-1097(19)31632-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Pessoa FG, Fonseca K, Mady C, Ribeiro ON, Oliveira-Fonoff AM, Salemi V, Saldiva P, Fernandes F, Ramires F. AIR POLLUTION IN MYOCARDIAL REMODELING. J Am Coll Cardiol 2017. [DOI: 10.1016/s0735-1097(17)34109-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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