Changes in the inspiratory pattern contribute to modulate the sympathetic activity in sino-aortic denervated rats

Autor(es)

Amorim, Mateus R. ^[1] ; Bonagamba, Leni G. H. ^[1] ; Souza, George M. P. R. ^[1] ; Moraes, Davi J. A. ^[1] ; Machado, Benedito H. ^[1]

Afiliação do(s) autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: Experimental Physiology; v. 102, n. 9, p. 1100-1117, SEP 1 2017.
• Citações Web of Science: 5

Resumo

The activity of presympathetic neurons is under respiratory modulation, and changes in the central respiratory network may impact on the baseline sympathetic activity and mean arterial pressure. It is well known that after removal of baroreceptor afferents {[}sino-aortic denervation (SAD)], rats present an unexpected normal level of mean arterial pressure. We hypothesized that changes in the respiratory pattern and in the respiratory modulation of the sympathetic activity contribute to keep the sympathetic outflow within a normal range of variation in the absence of arterial baroreceptors in rats. To study these mechanisms, we recorded perfusion pressure and the activities of phrenic and thoracic sympathetic nerves in male juvenile rats using the working heart-brainstem preparation. The time of inspiration significantly increased in SAD rats, and this change was not dependent on the carotid bodies or on the vagal afferents. However, no changes were observed in the perfusion pressure or in the baseline thoracic sympathetic nerves in all phases of the respiratory cycle in SAD rats. Our data show that despite longer inspiratory activity, the baseline sympathetic activity is maintained at a normal level in SAD rats. These findings indicate that the respiratory-sympathetic coupling is normal after SAD and suggest that the respiratory modulation of sympathetic activity is maintained within the normal range after the removal of arterial baroreceptors. (AU)

• Processo FAPESP: 13/06077-5 - Alterações nas redes neurais envolvidas na geração e controle das atividades simpática e respiratória em diferentes modelos experimentais de hipóxia
• Beneficiário: Benedito Honorio Machado
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/15195-1 - Caracterização eletrofisiológica dos neurônios respiratórios e pré-simpáticos da região rostral ventrolateral do bulbo após a desnervação sino-aórtica em ratos
• Beneficiário: Mateus Ramos Amorim
• Linha de fomento: Bolsas no Brasil - Doutorado