Tramadol-induced addiction shows sex-dependent variation response in pubescent adolescent Wistar rats

Tramadol is an opioid commonly prescribed for the treatment of moderate to severe pain and its abuse creates addiction. According to WHO, 36 million people worldwide suffer from disorders related to drug abuse. Among the consume substances, opioid such as Tramadol, is one of the most used. Therefore, the aim of this study was to evaluate gender variation in response to tramadol abuse. Tramadol (50 mg/kg, p.o) was administered to 28 Wistar rats from both sexes (14 males and 14 females) to induce addictive behavior and was assessed for 12 days on the conditioned place preference (CPP) test. Hyperactivity and risk taking linked to addiction were also assessed on the Elevated plus maze (EPM). On day 12 one hour after the CPP, animals were sacrificed by cervical dislocation and, striatum and hippocampus were collected for biochemicals assay (dopamine, GABA, nitric oxide and malondialdehyde). Tramadol intake induced dependency to tramadol and addictive seeking behavior in CPP in both sexes. Hyperactivity and risk taking assessed on EPM were present in both sexes. Tramadol increased dopamine and reduced GABA in both sexes and increased the malondialdehyde and nitric oxide production. Generally, variations were greater in females. So, these results suggest that pubescent female adolescents showed greater susceptibility to Tramadol abuse induced addictive behavior than males at least in the basic parameters assessed.