CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
artículos
Título:
A PREVIOUS HISTORY OF REPEATED AMPHETAMINE EXPOSURE MODIFIES BRAIN ANGIOTENSIN II AT1 RECEPTOR FUNCTIONALITY
Autor/es:
CASARSA, BS; MARINZALDA, M; MARCHESE, NA; PAZ, MC; VIVAS, L; BAIARDI, G; BREGONZIO, C
Revista:
NEUROSCIENCE
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2015 p. 1 - 13
ISSN:
0306-4522
Resumen:
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 mediated by angiotensin II (ANG II) AT1-R activation in animals previously exposed to amphetamine. For this purpose male Wistar rats (250-320g) were treated with amphetamine (2.5mg/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 (400pmol) 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 immunoreactivity 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 desensitization of AT1-R in response to ANG II, induced by repeated amphetamine exposure. This functional AT1-R desensitization 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.