Lithium (Li) is a typical mood stabilizer and the first choice for treatment of bipolar disorder (BD). Despite an extensive clinical use of Li, its mechanisms of action remain widely different and debated. In this work, we studied the time-course of the therapeutic Li effects on ouabain-sensitive Na+/K+-ATPase in forebrain cortex and hippocampus of rats exposed to 3-day sleep deprivation (SD). We also monitored lipid peroxidation as malondialdehyde (MDA) production. In samples of plasma collected from all experimental groups of animals, Li concentrations were followed by ICP-MS. The acute (1 day), short-term (7 days) and chronic (28 days) treatment of rats with Li resulted in large decrease of Na+/K+-ATPase activity in both brain parts. At the same time, SD of control, Li-untreated rats increased Na+/K+-ATPase along with increased production of MDA. The SD-induced increase of Na+/K+-ATPase and MDA was attenuated in Li-treated rats. While SD results in a positive change of Na+/K+-ATPase, the inhibitory effect of Li treatment may be interpreted as a pharmacological mechanism causing a normalization of the stress-induced shift and return the Na+/K+-ATPase back to control level. We conclude that SD alone up-regulates Na+/K+-ATPase together with increased peroxidative damage of lipids. Chronic treatment of rats with Li before SD, protects the brain tissue against this type of damage and decreases Na+/K+-ATPase level back to control level.

• MeSH
• antimanika farmakologie   terapeutické užití   MeSH
• hipokampus účinky léků   metabolismus   MeSH
• kompetitivní vazba účinky léků   MeSH
• krysa rodu rattus MeSH
• lithiumkarbonát farmakologie   MeSH
• malondialdehyd metabolismus   MeSH
• ouabain metabolismus   MeSH
• peroxidace lipidů účinky léků   MeSH
• potkani Wistar MeSH
• přední mozek účinky léků   enzymologie   metabolismus   MeSH
• sodíko-draslíková ATPasa metabolismus   MeSH
• spánková deprivace farmakoterapie   enzymologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Regulation of Na+/K+-ATPase in bipolar disorder and lithium therapy has been investigated for more than 40 years. Contradictory results in this area may be caused by the difference between acute and long-term Li effects on cell metabolism and variance in responsiveness of different cell types. We compared the time-course of Li action focusing on Na+/K+-ATPase and lipid peroxidation in two widely different cell models-Jurkat and HEK293. Na+/K+-ATPase expression level was determined in cells cultivated in the absence or presence of 1 mM Li for different time spans (1, 7, and 28 days) using [3H] ouabain binding and immunoblot assay of α-subunit. In parallel samples, the formation of malondialdehyde (MDA) was quantified by HPLC, and 4-hydroxy-2-nonenal (4-HNE) protein adducts were determined by immunoblot. Cultivation of Jurkat cells in 1 mM Li medium resulted in downregulation of Na+/K+-ATPase (decrease of [3H] ouabain-biding sites and intensity of immunoblot signals) in all Li-groups. In HEK293 cells, the decrease of Na+/K+-ATPase was observed after the acute, 1-day exposure only. The long-term treatment with Li resulted in Na+/K+-ATPase upregulation. MDA and 4-HNE modified proteins were decreased in Jurkat cells in all Li-groups. On the other hand, in HEK293 cells, MDA concentration was decreased after the acute, 1-day Li exposure only; the long-term cultivations, for 7 or 28 days, resulted in a significant increase of lipid peroxidation products. The Li-induced decrease of lipid peroxidation products was associated with the decrease of Na+/K+-ATPase level and vice versa.

• MeSH
• bipolární porucha farmakoterapie   metabolismus   MeSH
• časové faktory MeSH
• HEK293 buňky MeSH
• Jurkat buňky MeSH
• lidé MeSH
• lipidové peroxidy metabolismus   MeSH
• peroxidace lipidů účinky léků   MeSH
• regulace genové exprese účinky léků   MeSH
• sloučeniny lithia aplikace a dávkování   metabolismus   farmakologie   MeSH
• sodíko-draslíková ATPasa genetika   metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The functional state of δ-opioid receptor signaling cascade in live cells exposed to a therapeutic concentration of lithium for a prolonged period of time (weeks) is not known because the previous studies of Li interference with OR were oriented to µ-OR only. The same applies to the analysis of the prolonged effect of Li on oxidative stress in context with δ-OR function. HEK293 cells stably expressing δ-OR were cultivated in the presence or absence of 1 mM LiCl for 7 or 21 days, homogenized and the post-nuclear (PNS) and plasma membrane (PM) fractions prepared from all four types of cells. Level of δ-OR in PM was determined by specific radioligand [3H]DADLE binding and immunoblot assays; the functional coupling between δ-OR and G proteins was determined as DADLE-stimulated high-affinity [35S]GTPγS binding. In the whole cells, general oxidative stress was monitored by fluorescent dye 2',7'-dichlorofluorescein diacetate (DCF) and results verified by analysis of PNS and isolated PM. Generation of 4-hydroxy-2-nonenal (4-HNE)-protein adducts and malondialdehyde (MDA) level were determined as products of lipid peroxidation. Li-treated cells exhibited the decreased amount of δ-OR. This was evidenced by both [3H]DADLE binding and immunoblot assays. The δ-OR-G protein coupling efficiency was diminished. Simultaneously, in Li-treated cells, the highly increased oxidative stress measured as DCF fluorescence intensity was noticed. Importantly, this result was detected in live cells as well as PNS and PM. Accordingly, production of 4-HNE-protein adducts and MDA was clearly increased in Li-treated cells. The general significance of our work lies in presentation of novel data indicating that prolonged exposure of live HEK293 cells to the therapeutic concentration of Li results in down-regulation of δ-OR protein level and attenuation of δ-OR function in parallel with increased oxidative stress and increased level of lipid peroxidation products.

• MeSH
• chlorid lithný aplikace a dávkování   MeSH
• down regulace účinky léků   fyziologie   MeSH
• HEK293 buňky MeSH
• lidé MeSH
• oxidační stres účinky léků   fyziologie   MeSH
• receptory opiátové delta antagonisté a inhibitory   metabolismus   MeSH
• rozvrh dávkování léků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH