tianeptine pretreatment upon corticosterone release and body weight loss following L-5-hydroxytryptophan (5-HTP) administration in conscious rats.?Administration of 5-HTP (20 mg/kg i.v.) increased plasma corticosterone levels to a similar extent in rats pretreated either with saline or tianeptine (10 mg/kg i.p., 60 min beforehand).?Besides, prior administration of benserazide (50 mg/kg i.p., 30 min beforehand), an inhibitor of peripheral aromatic L-amino acid decarboxylase, prevented 5-HTP-induced corticosterone release in both saline- and tianeptine-pretreated rats.?However, combined administration of benserazide and 5-HTP decreased overnight body weight in saline-, but not in tianeptine-pretreated rats.?These results suggest that tianeptine preferentially activates 5-HT reuptake in central serotonergic neurones.