Swimming training reduces iNOS expression, augments the antioxidant defense and reduces sympathetic responsiveness in the rostral ventrolateral medulla of normotensive male rats

Autor(es)

Raquel, Hiviny de Ataides ^{[1, 2]} ; Souza Guazelli, Carla Fabiana ^[3] ; Verri Jr, Waldiceu A. ; Michelini, Lisete C. ^[1] ; Martins-Pinge, Marli Cardoso ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, Sao Paulo, SP - Brazil

^[2] Univ Estadual Londrina, Ctr Biol Sci, Dept Physiol Sci, Rodovia Celso Garcia Cid, Km 380, Campus Univ, BR-86055900 Londrina, Parana - Brazil

^[3] Univ Estadual Londrina, Ctr Biol Sci, Dept Pathol Sci, Londrina, Parana - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brain Research Bulletin; v. 170, p. 225-233, MAY 2021.
• Citações Web of Science: 0

Resumo

We sought to investigate whether RVLM iNOS activity and oxidative profile may participate in the reduction of sympathetic responsiveness in swimming trained normotensive rats. Sedentary (S) and swimming trained (T) Wistar male rats chronically instrumented with an arterial catheter and guide cannula into the RVLM were submitted to continuous pressure and heart rate (HR) recordings and determination of autonomic control (power spectral analysis) before and after unilateral RVLM iNOS inhibition (aminoguanidine, 250 pmol/100 nL). Other S and T rats received local L-glutamate micminjection (5 nmol/100 nL). In separate S and T groups not submitted to brainstem cannulation, fresh bilateral RVLM punchs were collected for iNOS gene expression (qPCR); reduced glutathione and lipid pemxidation quantification (spectrophotometry); iron-reducing antioxidant (FRAP) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS(+)) scavenger assays. iNOS gene expression was confirmed in fixed RVLM slices (immunofluorescence). T rats exhibited resting bradycardia, lower sympathovagal balance, reduced RVLM iNOS gene/protein expression and higher antioxidant capacity. Decreased iNOS expression was positively correlated with reduced HR. Pressor and tachycardic response to L-Glutamate were smaller in T rats. Aminoguanidine micminjection reduced sympathetic activity in S rats but did not change it in T rats expressing reduced RVLM iNOS content. Our data indicate that iNOS, expressed in the RVLM of normotensive male rats, has tonic effects on sympathetic activity and that swimming training is an efficient tool to reduce iNOS expression and augment the antioxidant defense, thus reducing glutamatergic responsiveness and sympathetic drive to cardiovascular effectors. (AU)

• Processo FAPESP: 15/24935-4 - Barreira hematoencefálica e regulação autonômica na hipertensão arterial: efeitos da angiotensina ii e do treinamento aeróbio
• Beneficiário: Lisete Compagno Michelini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/22156-3 - Efeitos da insuficiência cardíaca e do treinamento aeróbio sobre a integridade da barreira hematoencefálica em áreas de controle autonômico: Mecanismos envolvidos no transporte paracelular e transcelular.
• Beneficiário: Hiviny de Ataides Raquel
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado