BREGONZIO DIAZ CLAUDIA
Congresos y reuniones científicas
Título:
A Centrally Acting, Anxiolytic Angiotensin II AT(1) Receptor Antagonist Prevents the Isolation Stress-Induced Decrease in Cortical CRF(1) Receptor and Benzodiazepine Binding.
Autor/es:
8. PAVEL, J.; ARMANDO, I.; BREGONZIO, C.; JUORIO, A; MACOVA, M. ; SAAVEDRA, J.M.
Lugar:
Washington, DC, USA
Reunión:
Congreso; Neuroscience Meeting; 2005
Resumen:
The brain and the peripheral Angiotensin II systems are stimulated during stress. Long term pretreatment with AT1 antagonists blocks many of the well-known effects of Angiotensin II in peripheral organs and in the brain, and almost completely abolishes the sympathoadrenal and hypothalamo-pituitary-adrenal responses to isolation stress. Whether AT1 receptors are also important for the response of higher regulatory centers during stress is not fully clear. We studied corticotrophin-releasing hormone (CRH) receptors and benzodiazepine binding sites in cortex of Wistar Hanover rats, which were pretreated for 13 days with vehicle or a central and peripheral AT1 antagonist (candesartan, 1.0 mg/kg/day) via osmotic minipumps followed by 24hs of isolation in metabolic cages. In another study, we determined the influence of a similar treatment with the AT1 receptor antagonist on behavior of experimental animals in an elevated plus-maze. Pretreatment with candesartan completely prevented the decrease in cortical CRH1 receptor and benzodiazepine binding produced by isolation stress, and moreover, increased the time spent in and the number of entries to the open arm of the elevated plus-maze, a measure of decreased anxiety. Our results indicate a modulation of cortical CRH1 receptors and the GABAA complex as a molecular mechanism responsible for the anti-anxiety effect of centrally-acting AT1 receptor antagonist. We propose that candesartan can be considered as a compound with possible therapeutic anti-stress and anti-anxiety properties.
