title: Tramadol pretreatment enhances ketamine-induced antidepressant effects and increases mammalian target of rapamycin in rat hippocampus and prefrontal cortex.
abstract: Several lines of evidence have demonstrated that acute administration of ketamine elicits fast-acting antidepressant effects. Moreover, tramadol also has potential antidepressant effects. The aim of this study was to investigate the effects of pretreatment with tramadol on ketamine-induced antidepressant activity and was to determine the expression of mammalian target of rapamycin (mTOR) in rat hippocampus and prefrontal cortex. Rats were intraperitoneally administrated with ketamine at the dose of 10 mg/kg or saline 1 h before the second episode of the forced swimming test (FST). Tramadol or saline was intraperitoneally pretreated 30 min before the former administration of ketamine or saline. The locomotor activity and the immobility time of FST were both measured. After that, rats were sacrificed to determine the expression of mTOR in hippocampus and prefrontal cortex. Tramadol at the dose of 5 mg/kg administrated alone did not elicit the antidepressant effects. More importantly, pretreatment with tramadol enhanced the ketamine-induced antidepressant effects and upregulated the expression of mTOR in rat hippocampus and prefrontal cortex. Pretreatment with tramadol enhances the ketamine-induced antidepressant effects, which is associated with the increased expression of mTOR in rat hippocampus and prefrontal cortex.
authors.affiliation: Department of Anesthesiology, School of Medicine, Jinling Hospital, Nanjing University, Jiangsu, Nanjing, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Li
authors.forename: Hai-Yin
authors.initials: HY
authors.lastname: Yu
authors.forename: Zhi-Qin
authors.initials: ZQ
authors.lastname: Gao
authors.forename: Xiang-Liu
authors.initials: XL
authors.lastname: Liu
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Zhou
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Yang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D015153:Blotting, Western; D004357:Drug Synergism; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D014147:Tramadol / Q000494:pharmacology*
chemical_list: D000928:Antidepressive Agents; D014147:Tramadol; D007649:Ketamine; C546845:mTOR protein, rat; D058570:TOR Serine-Threonine Kinases