Evaluation of role of noradrenergic system in the antidepressant activity of tramadol using tail suspension test in Albino mice

Opioid peptides and their receptors are potential candidates for the development of novel antidepressant treatment. Tramadol is a synthetic 4-phenyl-piperidine analogue of codeine. It is a central analgesic with a low affi nity for opioid receptors. Experimental and clinical data suggest that tramadol may also exert its analgesic effect through direct modulation of central monoaminergic pathways. The action of tramadol on the monoaminergic reuptake is similar to that of antidepressant drugs.[1-3] Several studies have suggested that tramadol could play a role in mood improvement. This study was undertaken to evaluate the role of noradrenergic system in the antidepressant activity of tramadol in a test predictive of antidepressant activity in mice.