- Title
- Involvement of GABAergic and Adrenergic Neurotransmissions on Paraventricular Nucleus of Hypothalamus in the Control of Cardiac Function
- Creator
- Mendonça, Michelle M.; Santana, Joice S.; da Cruz, Kellen R.; Ianzer, Danielle; Ghedini, Paulo C.; Nalivaiko, Eugene; Fontes, Marco A. P.; Ferreira, Reginaldo N.; Pedrino, Gustavo R.; Colugnati, Diego B.; Xavier, Carlos H.
- Relation
- Frontiers in Physiology Vol. 9, no. 670
- Publisher Link
- http://dx.doi.org/10.3389/fphys.2018.00670
- Publisher
- Frontiers Research Foundation
- Resource Type
- journal article
- Date
- 2018
- Description
- Sympathetic premotor neurons of the paraventricular hypothalamus (PVN) play a role in hemodynamics adjustments during changes in body fluid homeostasis. However, PVN contribution to the tonic control of cardiac function remains to be systematically studied. In this study, we assessed whether GABAergic and adrenergic synapses, known for being active in the PVN, are involved in the control of cardiac function. Adult male Wistar rats (250–350 g; n = 27) were anesthetized with urethane (1.2–1.4 g/kg i.p.) and underwent catheterization of femoral artery to record blood pressure and heart rate. The femoral vein was used to inject the vasoactive agents phenylephrine (10 μg/kg) and sodium nitroprusside (10 μg/kg) and to supplement anesthesia. The cardiac left ventricle was catheterized to record left ventricular pressure and its derivative. Craniotomy allowed for injections (100 nL) into the PVN of: muscimol (20 mM), bicuculline methiodide (0.4 mM), propranolol (10 mM), isoproterenol (100 μM), phentolamine (13 mM), phenylephrine (30 nM). We found that: (i) inhibition of PVN by muscimol, reduced arterial pressure, cardiac chronotropy and inotropy; (ii) disinhibition of PVN neurons by bicuculline evoked positive chronotropy and inotropy, and increase blood pressure; (iii) PVN alpha adrenergic receptors control cardiac chronotropy and inotropy; (iv) beta adrenergic receptors of the PVN do not influence cardiac function; (v) afterload does not contribute to the PVN-evoked inotropy. Our results indicate that the modulation of the activity of PVN neurons exerted by GABAergic and adrenergic mechanisms contribute to the control of cardiac function.
- Subject
- cardiac contractility; paraventricular nucleus; autonomic nervous system; cardiac function; sympathetic nervous system
- Identifier
- http://hdl.handle.net/1959.13/1458824
- Identifier
- uon:45514
- Identifier
- ISSN:1664-042X
- Rights
- © 2018 Mendonça, Santana, da Cruz, Ianzer, Ghedini, Nalivaiko, Fontes, Ferreira, Pedrino, Colugnati and Xavier. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) (http://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
- Language
- eng
- Full Text
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