Angiotensin II type 1 receptor blocker losartan effect on rats exposed to predator odor

Background and Aim : Predator odor induces anxiety-like behaviors in rats. Stress has destructive effect on neuronal circuits in brain which gives rise to many psychological disorders. Furthermore, studies have shown the existence of AT1 receptors in brain which play a role in stress responses. This study intention was to investigate the losartan (AT1 antagonist) treatment effects on rat’s behavioral response undergoing predator odor stress and non-stress.Methods : . Each of sham and stress exposed group was divided to 4 subgroups (n =8). In non-associated groups, the rats were exposed to an unscented piece of cloth, and in the associated groups the unscented cloth was replaced with a cat-scented cloth associated with a cue. The losartan and normal saline were injected one hour before predator odor exposure and the behavioral tests applied after 10 days.Results : Losartan significantly increased the time spent in the compartment associated with the cue. In the EMP task losartan had also the same effect by increasing the time spent in open arms.Conclusion : . Our findings showed the beneficial effects of losartan on anxiety behaviors via inhibition of AT1 receptors. In general, it can be concluded that induction of predator odor stress in rats resulted in anxiety, and the effect was reversed by losartan.

Keywords:

Anxiety , Losartan , Predator , Stress