Effects of mood stabilizer lithium on noradrenergic turnover in the prefrontal cortex of chronically stressed rats.

ABSTRACT

OBJECTIVE: Data about the dynamics of noradrenaline (NA) transmission, storage and degradation may be very important for understanding the reduction of functional deficiency of NA and maintaining the stability of NA levels in animals with depressive-like behavior treated with lithium. This study aimed to investigate the effects of mood stabilizer lithium on concentrations of NA in the prefrontal cortex (PFC), as well as behavior rats exposed to chronic restraint stress (CRS). In addition, this study examined the effects of lithium on protein levels of noradrenaline transporter (NET), vesicular monoamine transporter 2 (VMAT2) and catechol-O-methyltransferase (COMT), as well as the enzyme activity of monoamine oxidase A (MOA) in the PFC of chronically stressed rats. METHODS: The investigated parameters were quantified by Western blot analysis, CAT Research ELISA kits, and an assay of enzyme activity. Also, the forced swim test (FST) was used to assess the behavior of animals. RESULTS: We found that lithium treatment decreased high protein levels of NET and VMAT2, as well as the enzyme activity of MOA in chronically stressed rats to the levels found in unstressed animals. In addition, lithium treatment decreased the concentration of NA (24%) and immobility in animals exposed to CRS. CONCLUSION: Our data confirm that lithium-induced modulation of prefrontal noradrenergic turnover and stabilized the behavior of chronically stressed rats.