Autonomic cardiocirculatory control in mice with reduced expression of the vesicular acetylcholine transporter

Autor(es)

Durand, Marina T. ^[1] ; Becari, Christiane ^[1] ; Tezini, Geisa C. S. V. ^[1] ; Fazan, Jr., Rubens ^[1] ; Oliveira, Mauro ^[1] ; Guatimosim, Silvia ^[2] ; Prado, Vania F. ^{[3, 4]} ; Prado, Marco A. M. ^{[3, 4]} ; Salgado, Helio C. ^[1]

Afiliação do(s) autor(es)

^[1] Ribeirao Preto Med Sch, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Minas Gerais, Dept Physiol & Biophys, Inst Biol Sci, Belo Horizonte, Minas Gerais - Brazil

^[3] Univ Western Ontario, Robarts Res Inst, Dept Anat & Cell Biol, London, ON - Canada

^[4] Univ Western Ontario, Robarts Res Inst, Dept Physiol & Pharmacol, London, ON - Canada

• Tipo de documento: Artigo Científico
• Fonte: AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY; v. 309, n. 4, p. H655-H662, AUG 15 2015.
• Citações Web of Science: 4

Resumo

In cardiovascular diseases, sympathetic tone has been comprehensively studied, whereas parasympathetic tone has received minor attention. The vesicular ACh transporter (VAChT) knockdown homozygous (VAChT KDHOM) mouse is a useful model for examining the cardiocirculatory sympathovagal balance. Therefore, we investigated whether cholinergic dysfunction caused by reduced VAChT expression could adversely impact hemodynamic parameter {[}arterial pressure (AP) and heart rate (HR)] daily oscillation, baroreflex sensitivity, hemodynamic variability, sympathovagal balance, and cardiovascular reactivity to restraint stress. Wild-type and VAChT KDHOM mice were anesthetized for telemetry transmitter implantation, and APs and HRs were recorded 10 days after surgical recovery. Changes in HR elicited by methylatropine and propranolol provided the indexes of sympathovagal tone. Cardiovascular reactivity in response to a restraint test was examined 24 h after continuous recordings of AP and HR. VAChT KDHOM mice exhibited reduced parasympathetic and elevated sympathetic tone. Daily oscillations of AP and HR as well as AP variability were similar between groups. Nevertheless, HR variability, patterns with two dissimilar variations from symbolic analysis, and baroreflex sensitivity were reduced in VAChT KDHOM mice. The change in mean AP due to restraint stress was greater in VAChT KDHOM mice, whereas the tachycardic response was not. These findings demonstrate that the cholinergic dysfunction present in the VAChT KDHOM mouse did not adversely impact basal hemodynamic parameters but promoted autonomic imbalance, an attenuation of baroreflex sensitivity, and a greater pressure response to restraint stress. These results provide a framework for understanding how autonomic imbalance impacts cardiovascular function. (AU)

• Processo FAPESP: 13/20549-7 - Avanços na regulação cardiocirculatória em condições fisiológica e fisiopatológica
• Beneficiário: Helio Cesar Salgado
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/01089-8 - Regulação cardiocirculatória de camundongos com atenuação ou superexpressão do gene do transportador vesicular da acetilcolina (VAChT): função do parassimpático na insuficiência cardíaca
• Beneficiário: Geisa Cristina Singolani Vaccari Tezini Reis
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 13/06452-0 - REGULAÇÃO CARDIOCIRCULATÓRIA DE CAMUNDONGOS COM ATENUAÇÃO OU SUPEREXPRESSÃO DO GENE DO TRANSPORTADOR VESICULAR DA ACETILCOLINA (VAChT): FUNÇÃO DO PARASSIMPÁTICO NA INSUFICIÊNCIA CARDÍACA.
• Beneficiário: Geisa Cristina Singolani Vaccari Tezini Reis
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado