Telmisartan attenuates cognitive impairment caused by chronic stress in rats

Abstract

Background: The potential effect of chronic treatment with telmisartan, an angiotensin type 1 receptor blocker (ARB) and partial agonist of peroxisome proliferator--activated receptor γ (PPARγ), on stress-related disorders is a matter of considerable interest. The existing data suggest that angiotensin II (Ang II) plays a major role in exaggerated sympathetic and hormonal response to stress. Enhanced formation of Ang II and increased AT1 receptor activity is associated with devastating impact of stress on central nervous system, which may trigger many psychiatric disorders such as depression, schizophrenia or post-traumatic stress disorder. Some of the anti-stress effects of ARBs have already been proven but these on the stress-induced cognitive impairment were examined only for candesartan. In this study, we tested a hypothesis that blockade of stress response by another ARB telmisartan alleviates the negative effect of prolonged restraint stress on cognitive functions of male Wistar rats.

Methods: The preventive action of long-lasting treatment with telmisartan (1mg/kg body weight) against impairment caused by chronic stress (2h daily for 21 days) on recall was evaluated in a passive avoidance (PA) situation and object recognition test (ORT). Locomotor activity and anxiety behavior were tested respectively, in an open field and an elevated plus-maze.

Results: The results of this study indicate that telmisartan diminishes deleterious effects of chronic restraint stress on memory in a statistically significant manner (p<0.01) in both, PA situation and ORT.

Conclusion: It appears that telmisartan may constitute a new therapeutic option in a stress-related cognitive impairment.

Keywords: ARB; Angiotensin II; Cognitive impairment; Restraint stress; Telmisartan.