A previous history of repeated amphetamine exposure modifies brain angiotensin II AT1 receptor functionality

Authors
Casarsa, Brenda Solange; Marinzalda, María de Los Angeles; Marchese, Natalia Andrea; Paz, Maria Constanza; Vivas, Laura Marta; Bregonzio, C.; Baiardi, Gustavo Carlos
Publication Year
2015
Language
English
Format
article
Status
Published version
Description
Previous results from our laboratory showed that angiotensin II AT1 receptors (AT1-R) are involved in the neuroadaptative changes induced by amphetamine. The aim of the present work was to study functional and neurochemical responses to angiotensin II (ANG II) mediated by AT1-R activation in animals previously exposed to amphetamine. For this purpose male Wistar rats (250–320 g) were treated with amphetamine (2.5 mg/kg/day intraperitoneal) or saline for 5 days and implanted with intracerebroventricular (i.c.v.) cannulae. Seven days after the last amphetamine administration the animals received ANG II (400 pmol) i.c.v. One group was tested in a free choice paradigm for sodium (2% NaCl) and water intake and sacrificed for Fos immunoreactivity (Fos-IR) determinations. In a second group of rats, urine and plasma samples were collected for electrolytes and plasma renin activity determination and then they were sacrificed for Fos-IR determination in Oxytocinergic neurons (Fos-OT-IR). Results: Repeated amphetamine exposure (a) prevented the increase in sodium intake and Fos-IR cells in caudate-putamen and accumbens nucleus induced by ANG II i.c.v. (b) potentiated urinary sodium excretion and Fos-OT-IR in hypothalamus and (c) increased the inhibitory response in plasma renin activity, in response to ANG II i.c.v. Our results indicate a possible functional desensitisation of AT1-R in response to ANG II, induced by repeated amphetamine exposure. This functional AT1-R desensitisation allows to unmask the effects of ANG II i.c.v. mediated by oxytocin. We conclude that the long lasting changes in brain AT1-R functionality should be considered among the psychostimulant-induced neuroadaptations.
Fil: Casarsa, Brenda Solange. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina
Fil: Marinzalda, María de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina
Fil: Marchese, Natalia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Farmacología Experimental de Córdoba; Argentina
Fil: Paz, Maria Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Farmacología Experimental de Córdoba; Argentina
Fil: Vivas, Laura Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Médicas Mercedes y Martín Ferreyra; Argentina
Fil: Bregonzio, C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Farmacología Experimental de Córdoba; Argentina
Fil: Baiardi, Gustavo Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina
Subject
AT1 receptors
angiotensin II
amphetamine
sodiun intake
natriuresis
oxytocin
Neurociencias
Medicina Básica
CIENCIAS MÉDICAS Y DE LA SALUD
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/11634