m-Trifluoromethyl-diphenyl Diselenide Regulates Prefrontal Cortical MOR and KOR Protein Levels and Abolishes the Phenotype Induced by Repeated Forced Swim Stress in Mice

The present study aimed to investigate the m-trifluoromethyl-diphenyl diselenide [(m-CF3-PhSe)2] effects on prefrontal cortical MOR and KOR protein levels and phenotype induced by repeated forced swim stress (FSS) in mice. Adult Swiss mice were subjected to repeated FSS sessions, and after that, they performed the spontaneous locomotor/exploratory activity, tail suspension, and splash tests. (m-CF3-PhSe)2 (0.1 to 5 mg/kg) was administered to mice 30 min before the first FSS session and 30 min before the subsequent repeated FSS. (m-CF3-PhSe)2 abolished the phenotype induced by repeated FSS in mice. In addition, a single FSS session increased μ but reduced δ-opioid receptor contents, without changing the κ content. Mice subjected to repeated FSS had an increase in the μ content when compared to those of naïve group or subjected to single FSS. Repeated FSS induced an increase of δ-opioid receptor content compared to those mice subjected to single FSS. However, the δ-opioid receptor contents were lower than those found in the naïve group. The mice subjected to repeated FSS showed an increase in the κ-opioid receptor content when compared to that of the naïve mice. (m-CF3-PhSe)2 regulated the protein contents of μ and κ receptors in mice subjected to repeated FSS. These findings demonstrate that (m-CF3-PhSe)2 was effective to abolish the phenotype induced by FSS, which was accompanied by changes in the contents of cortical μ- and κ-opioid receptors.