Impact of Tramadol Administration on Stomach and Duodenum of Male Rats: Histological Examinations, DNA and...

This study was conducted to elucidate the histopathological alterations in the stomach and duodenum, biochemical changes in selected enzymes and hormones in rat sera, and to investigate DNA damage in tissues resulting from tramadol administration. Thirty adult male rats weighing 180-200 g were randomly distributed in three groups: group I (control), group II of 10 animals received a single dose (50.4 mg) of tramadol hydrochloride (TR- HCl) orally, and group III of 10 rats received the same TR-HCl dose, fractionated into small, periodic, and incremental doses over 49 days. The first treatment period lasted for three weeks. At the end of this period, five rats from each group were separated and euthanized. The remaining animals were euthanized later after an additional four weeks. Histological examinations of stomach and duodenum specimens were performed as well as immune and biochemical analyses for trypsin, pepsin, testosterone, caspase-3 and tumor necrosis factor (TNF-α). A DNA fragmentation comet assay was carried out at the 3rd and 7th weeks from treatment onset. Based on the experimental results, it can be concluded that prolonged tramadol administration (weeks) can induce: gastric dysfunctions and duodenum injury, disturbance in selected enzymes and hormones, detectable DNA damage as well as degeneration in the endogenous antioxidant defense system mechanism in treated rats. Therefore, a firm control on the handling and administration of tramadol is needed to avoid and prevent its abuse and addiction, especially among adolescents.