Aldosterone infusion into the 4th ventricle produces sodium appetite with baroreflex attenuation independent of renal or blood pressure changes

Author(s)

Gasparini, S. ^{[1, 2]} ; Melo, M. R. ^[2] ; Andrade-Franze, G. M. F. ^[2] ; Geerling, J. C. ^[1] ; Menani, J. V. ^[2] ; Colombari, E. ^[2]

Affiliation

^[1] Univ Iowa, Dept Neurol, Carver Coll Med, Iowa City, IA 52242 - USA

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

• Document type: Journal article
• Source: Brain Research; v. 1698, p. 70-80, NOV 1 2018.
• Web of Science Citations: 1

Abstract

Aldosterone infusion into the 4th ventricle (4th V), upstream the nucleus of the solitary tract (NTS), produces strong 0.3 M NaCl intake. In the present study, we investigated whether aldosterone infusion into the 4th V activates HSD2 neurons, changes renal excretion, or alters blood pressure and cardiovascular reflexes. Chronic infusion of aldosterone (100 ng/h) into the 4th V increased daily 0.3 M NaCl intake (up to 44 +/- 10, vs. vehicle: 5.6 +/- 3.4 ml/24 h) and also c-Fos expression in HSD2 neurons in the NTS and in non-HSD2 neurons in the NTS. Natriuresis, diuresis and positive sodium balance were present in rats that ingested 0.3 M NaCl, however, renal excretion was not modified by 4th V aldosterone in rats that had no access to NaCl. 4th V aldosterone also reduced baroreflex sensitivity (-2.8 +/- 0.5, vs. vehicle: -5.1 +/- 0.9 bpm/mmHg) in animals that had sodium available, without changing blood pressure. The results suggest that sodium intake induced by aldosterone infused into the 4th V is associated with activation of NTS neurons, among them the HSD2 neurons. Aldosterone infused into the 4th V in association with sodium intake also impairs baroreflex sensitivity, without changing arterial pressure. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/00026-0 - Characterization of aldosterone action on hindbrain on the hydroeletrolytic control and cardiovascular regulation
• Grantee: Silvia Gasparini
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/23467-7 - Experimental pathophysiology: role of central mechanisms of the cardiovascular and respiratory control changes induced by experimental hypertension and obesity
• Grantee: Eduardo Colombari
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/04134-5 - Genetic identity and neural circuit connections of aldosterone-sensitive neurons in rat and mouse NTS
• Grantee: Eduardo Colombari
• Support Opportunities: Research Grants - Visiting Researcher Grant - International