Anxiolytic-like effect of losartan injected into amygdala of the acutely stressed rats.
Journal Title: Pharmacological Reports - Year 2012, Vol 64, Issue 1
Abstract
It has been recognized that the stress-related peptides are involved in anxiety states. Angiotensin II receptor blockade by systemic administration of the AT(1) receptor antagonists has been proposed as a new treatment possibility for anxiety disorders. For better understanding of the related mechanisms, in this study we evaluated effects of bilateral intraamygdaloid injections of 2 (LOS 2) and 4 (LOS 4) μg of losartan (LOS), a selective AT(1) receptor antagonist, on the behavior of the not stressed and acutely stressed rats in an elevated "plus" maze. Under non-stress conditions, LOS 4 increased time spent in the open arms (p < 0.01), number of extreme open arm arrivals (p < 0.05), time per entry (p < 0.01), and the number of total arm entries (p < 0.05) showing thus considerable anxiolytic activity. The open arm extreme arrivals were increased by LOS 4 in both not stressed (p < 0.05) and stressed (p < 0.05) rats. When no stressed and stressed LOS 4 animals were compared, time per entry and the number of closed arm entries (p < 0.05, both) were decreased in the latter group. Moreover, the LOS 4 stressed rats had significantly increased open/closed arm quotient (p < 0.05) as compared to the both control and LOS 4 non-stress group (p < 0.05, both). These findings suggest that the AT(1) receptor blockade in amygdala is important for the anxiolytic action of LOS (and probably other AT(1) receptor blockers) under both non-stress and stress conditions.
Authors and Affiliations
Luis López, Fernando Caif, Sebastián García, Miriam Fraile, Adriana Landa, Gustavo Baiardi, José Lafuente, Jan Braszko, Claudia Bregonzio, Pascual Gargiulo
Keywords
Related Articles
- EP ID EP135172
- DOI -
- Views 84
- Downloads 0
Tricaine (MS-222) is a safe anesthetic compound compared to benzocaine and pentobarbital to induce anesthesia in leopard frogs (Rana pipiens).
Tricaine (MS-222) is used commonly for sedation, immobilization, and anesthesia of poikilothermic animals. The anesthetic efficacy of different concentrations of MS-222 was compared to benzocaine and pentobarbital on the...
Antioxidant treatment normalizes renal Na(+),K(+)-ATPase activity in leptin-treated rats.
Hyperleptinemia may be involved in the pathogenesis of obesity-associated hypertension, however, the mechanism of hypertensive effect of leptin is incompletely elucidated. Previously, we have demonstrated that chronic hy...
Effects of thalidomide on the development of bone damage caused by prednisolone in rats.
Background: The methods used in treatment of osteoporosis induced by glucocorticosteroids are not effective enough. There is a need for new drugs which could be useful in counteracting the influence of glucocorticosteroi...
Therapeutic efficacy of naringin on cyclosporine (A) induced nephrotoxicity in rats: involvement of hemeoxygenase-1.
Background: Clinically, chronic nephrotoxicity may lead to renal functional impairment and progress to end stage renal failure. The renoprotective effect of a flavonoid naringin (NG) against cyclosporine A (CsA)-induced...
Operant self-administration of ethanol in Warsaw High-Preferring (WHP) and Warsaw Low-Preferring (WLP) lines of rats.
The results of the present experiment demonstrate that ethanol-preferring line of rats (WHP), and ethanol-nonpreferring line of rats (WLP) are able to acquire and maintain lever pressing reinforced by EtOH (oral operant...