Autor(es)

Mendonca-Junior, Bolival A. ^[1] ; Fernandes, V, Marcos ; Zoccal, Daniel B. ^[2]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, Sch Dent Araraquara, Dept Physiol & Pathol, UNESP, Rua Humaita 1680, BR-14801903 Araraquara, SP - Brazil

^[2] Fernandes, Marcos, V, Sao Paulo State Univ, Sch Dent Araraquara, Dept Physiol & Pathol, UNESP, Rua Humaita 1680, BR-14801903 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Respiratory Physiology & Neurobiology; v. 294, DEC 2021.
• Citações Web of Science: 0

Resumo

Acute intermittent hypoxia (AIH) modifies the functioning of the respiratory network, causing respiratory motor facilitation in anesthetized animals and a compensatory increase in pulmonary ventilation in freely behaving animals. However, it is still unclear whether the ventilatory facilitation induced by AIH in unanesthetized animals is associated with changes in the respiratory pattern. We found that Holtzman male rats (80-150 g) exposed to AIH (10 x 6% O2 for 30-40 s every 5 min, n = 9) exhibited a prolonged (30 min) increase in baseline minute ventilation (P < 0.05) compared to control animals (n = 13), combined with the occurrence of late expiratory peak flow events, suggesting the presence of active expiration. The increase in ventilation after AIH was also accompanied by reductions in arterial CO2 and body temperature (n = 5-6, P < 0.05). The systemic treatment with ketanserin (a 5-HT2 receptor antagonist) before AIH prevented the changes in ventilation and active expiration (n = 11) but potentiated the hypothermic response (n = 5, P < 0.05) when compared to appropriate control rats (n = 13). Our findings indicate that the ventilatory long-term facilitation elicited by AIH exposure in unanesthetized rats is linked to the generation of active expiration by mechanisms that may depend on the activation of serotonin receptors. In contrast, the decrease in body temperature induced by AIH may not require 5-HT2 receptor activation. (AU)

• Processo FAPESP: 13/17251-6 - Mecanismos neurais de geração do padrão respiratório e do acoplamento simpático-respiratório em condições de hipóxia
• Beneficiário: Daniel Breseghello Zoccal
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 18/21000-2 - Mecanismos iônicos recrutados durante a resposta ventilatória ao ATP: entendendo a interação entre sensores centrais para oxigênio e os neurônios geradores do ritmo respiratório
• Beneficiário: Daniel Breseghello Zoccal
• Modalidade de apoio: Bolsas no Exterior - Pesquisa