Involvement of endogenous central hydrogen sulfide (H2S) in hypoxia-induced hypothermia in spontaneously hypertensive rats

Autor(es)

Sabino, Joao Paulo J. ; Soriano, Renato N. ; Donatti, Alberto F. ; Fernandez, Rodrigo Restrepo ; Kwiatkoski, Marcelo ; Francescato, Heloisa D. C. ; Coimbra, Terezila M. ; Branco, Luiz G. S.

• Tipo de documento: Artigo Científico
• Fonte: Canadian Journal of Physiology and Pharmacology; v. 95, n. 2, p. 157-162, FEB 2017.
• Citações Web of Science: 1

Resumo

Spontaneously hypertensive rats (SHR) display autonomic imbalance and abnormal body temperature (Tb) adjustments. Hydrogen sulfide (H2S) modulates hypoxia-induced hypothermia, but its role in SHR thermoregulation is unknown. We tested the hypothesis that SHR display peculiar thermoregulatory response to hypoxia and that endogenous H2S overproduced in the caudal nucleus of the solitary tract (NTS) of SHR modulates this response. SHR and Wistar rats were microinjected into the fourth ventricle with aminooxyacetate (AOA, H2S-synthezing enzyme inhibitor) or sodium sulfide (Na2S, H2S donor) and exposed to normoxia (21% inspired O-2) or hypoxia (10% inspired O-2, 30 min). Tb was continuously measured, and H2S production rate was assessed in caudal NTS homogenates. In both groups, AOA, Na2S, or saline (i.e., control; 1 mu L) did not affect euthermia. Hypoxia caused similar decreases in Tb in both groups. AOA presented a longer latency to potentiate hypoxic hypothermia in SHR. Caudal NTS H2S production rate was higher in SHR. We suggest that increased bioavailability of H2S in the caudal NTS of SHR enables the adequate modulation of excitability of peripheral chemoreceptor-activated NTS neurons that ultimately induce suppression of brown adipose tissue thermogenesis, thus accounting for the normal hypoxic hypothermia. (AU)

• Processo FAPESP: 11/14779-4 - Efeito do sulfeto de hidrogênio (H2S) no NTS comissural sobre as respostas ventilatórias e hemodinâmicas à hipercapnia e hipóxia em animais hipertensos e normotensos
• Beneficiário: João Paulo Jacob Sabino
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/24950-3 - Papel do sulfeto de hidrogênio (H2S) na resposta ventilatória à hipercapnia
• Beneficiário: Luiz Guilherme de Siqueira Branco
• Linha de fomento: Auxílio à Pesquisa - Regular