Fourteen Days Post-Ovariectomy Estrogens Decline Is Associated with Anxiogenic Effects on Wistar Rats

On study of the effects of estrogen deficiency on anxiety disorder by using ovariectomised animals, one discrepancy was the difference in behavioral testing delay following ovariectomy and the paradigms used. Thus, the aim of this study was to evaluate the anxiogenic effects of fourteen-day estrogen decline subsequent to ovariectomy on Wistar rats using EPM (elevated plus-maze) and open field tests. As results, fourteen days of estrogens decline has induced an increase of anxiety-related behaviour by a reduction of the percentage of the number of entries into the open arm (p < 0.01) and an increase of the percentage of the number of entries into the closed arm (p < 0.01) during the elevated plus-maze test. This anxiety-like behaviour was confirmed on the open field test by a reduction of time spent in the centre of the arena (p < 0.05) as well as a reduction of crossing (p < 0.05) and an increase of the weight of faecal boli (p < 0.05) and grooming (p < 0.01). Meanwhile, the administration of diazepam or estradiol valerate (1 mg/kg BW each) has corrected the anxious-like behaviour in both tests paradigms. These results suggest that fourteen days of estrogens decline was associated with an anxiety-related behaviour. This experimental model can constitute an excellent tool for the study of anxiolytic substances in menopause-related anxiety.