Interaction of central angiotensin II and aldosterone on sodium intake and blood pressure

Autor(es)

Gasparini, S. ^{[1, 2]} ; Melo, M. R. ^{[1, 3]} ; Nascimento, P. A. ^[1] ; Andrade-Franze, G. M. F. ^[1] ; Antunes-Rodrigues, J. ^[4] ; Yosten, G. L. C. ^[5] ; Menani, J. V. ^[1] ; Samson, W. K. ^[5] ; Colombari, E. ^{[1, 6]}

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Sch Dent, Dept Physiol & Pathol, Araraquara - Brazil

^[2] Univ Iowa, Dept Neurol, Iowa City, IA 52242 - USA

^[3] Univ Melbourne, Dept Physiol, Melbourne, Vic - Australia

^[4] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, Ribeirao Preto - Brazil

^[5] St Louis Univ, Dept Physiol & Pharmacol, St Louis, MO 63103 - USA

^[6] Univ Estadual Paulista, UNESP, Fac Odontol Araraquara, Dept Fisiol & Patol, Rua Humaita 1680, BR-14801903 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brain Research; v. 1720, OCT 1 2019.
• Citações Web of Science: 1

Resumo

Recent studies demonstrated an important natriorexigenic mechanism activated by aldosterone acting in the hindbrain. Studies have also shown that aldosterone effects are intensified by angiotensin II (ANG II) and vice-versa. Thus, the aim of the present work was to test if angiotensinergic mechanisms in the forebrain are involved on sodium appetite to aldosterone infused into the 4th V and also if aldosterone into the 4th V might facilitate ingestive and cardiovascular responses to central ANG II. Male Holtzman rats with stainless steel cannulas implanted into the 4th ventricle (4th V) and lateral ventricle (LV) had access to 1.8% NaCl during 2h/day. Chronic infusion of aldosterone (100 ng/h) into the 4th V for 7 days strongly increased 1.8% NaCl intake (16.1 +/- 2.2 ml/2h/day). Losartan (AT1 receptor antagonist, 50 mu g/1 mu l) acutely injected into the LV reduced 1.8% NaCl intake induced by aldosterone infusion into the 4th V (8.8 +/- 2.3 ml/2h/day). The pressor response to ANG II (50 ng/1 mu l) into the LV increased in rats treated with aldosterone into the 4th V (45 +/- 5 mmHg, vs. vehicle infusion: 26 +/- 4 mmHg). Similarly, fluid intake (water + 1.8% NaCl) also increased when rats receiving aldosterone infusion were treated with ANG II acutely into the LV. These results suggest that forebrain angiotensinergic mechanisms are important for sodium intake produced by aldosterone acting in the hindbrain. In addition, aldosterone in the hindbrain produces sensitization of the central pressor mechanisms activated by ANG II acting in the forebrain. (AU)

• Processo FAPESP: 13/00026-0 - Caracterização das ações da aldosterona no tronco cerebral sobre o controle do equilíbrio hidroeletrolítico e regulação cardiovascular
• Beneficiário: Silvia Gasparini
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 11/50770-1 - Mecanismos neurais de regulação do equilíbrio hidroeletrolítico e controle cardiorrespiratório
• Beneficiário: José Vanderlei Menani
• Modalidade de apoio: Auxílio à Pesquisa - Temático