THE EFFECT OF TIANEPTINE AND SERTRALINE IN 3 ANIMAL-MODELS OF DEPRESSION

The activity of tianeptine (2.5 and 5.0 mg kg twice daily, i.p.) and of sertraline (5.0 mg kg, twice daily, i.p.) were assessed in three animal models of depression. In the Behavioural Despair Test, acute treatment with sertraline or tianeptine (5.0 mg kg) significantly reduced the immobility time. In the olfactory bulbectomized (OB) rat model, chronic treatment with tianeptine (2.5 and 5.0 mg kg) or sertraline (5.0 mg kg) antagonized the lesion-induced hyperactivity in the open field apparatus. The hypothermic response to the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT, 0.15 mg kg, s.c.) was significantly attenuated after chronic setraline treatment, whereas tianeptine was inactive at the 2 doses tested. Neither drug affected the hypersection of corticosterone that occurs at the light:dark interface. A reduction in the serotonin metabolite 5-HIAA was found in the hypothalamus of sertraline-treated sham rats. It can be concluded that although the neurochemical properties of sertraline and tianeptine differ, they demonstrate similar antidepressant-like activities in the Behavioural Despair and OB rat models. The lack of effect of tianeptine on the 8-OH-DPAT-induced hypothermic effect indicates that it does not induce 5-HT1A subsensitivity, contrary to most antidepressants.