Effect of tianeptine on neuroendocrine, enzyme and behavioral responses to restraint stress in male rats

Summary The effects of the novel antidepressant tianeptine, after acute or chronic administration, were compared in normal and restraint-stressed (30 min or 2 h) Wistar rats. Tianeptine, at the dose of 10 mg/kg, did not exert any effect in non-stressed rats. However, in animals restrained for 30 min, tianeptine reduced the increase of circulating ACTH and β-endorphin levels without modification of corticosterone. Moreover, it antagonized the deficit of vertical exploratory activity in an open field. In rats restrained for 2 hours, a single injection of tianeptine suppressed the stress-induced increase of TAT hepatic activity and moderately attenuated the deficit of activity in the open field. This effect was less marked and not statistically significant after chronic treatment.