Analgesic effect of tianeptine in mice

The effects of tianeptine, a novel and unusual tricyclic antidepressant dru g, on tail-flick and hot-plate tests, which are two thermal analgesia evalu ating methods, have been investigated in mice. Tianeptine (5 and 10 mg/kg), para-chlorophenylalanine (pCPA) (100 mg/kg) and a combination of pCPA and tianeptine (10 mg/kg) or saline were injected to mice intraperitoneally. pC PA (100 mg/kg) was injected 24 h before tianeptine or saline treatment when it was combined with tinaeptine (10 mg/kg) or tested alone. The tail-flick latencies and hat-plate reaction times of the mice were measured between 1 5(th) and 180(th) minutes following injections. Tianeptine (10 mg/kg) exhib ited a significant antinociceptive activity that could be measured by both tests as compared to groups which were treated with saline or pCPA alone be tween 15(th) and 180(th) min of the observation period. The lower dose of t ianeptine (5 mg/kg) or pCPA (100 mg/kg) did not produce any significant cha nges on tail-flick latency or hot-plate reaction time of the mice. However, pretreatment with pCPA completely blocked the antinociceptive effect induc ed by tianeptine (10 mg/kg) in both tests used in the present study. Furthe rmore, tianeptine (10 mg/kg) did not cause any significant impairment effec ts on rotarod performance of the mice. Our results suggested that tianeptin e has a prominent thermal antinociceptive activity in mice and that increas ed serotonergic activity may be responsible for the analgesic effect of tia neptine.