Weeks Of Lithium Administration Research Articles

Differential expression profile between amygdala and blood during chronic lithium treatment in a rat model of depression – a pilot study

Lithium is a mood stabilizer widely used in the pharmacotherapy of bipolar disorder and treatment‑resistant depression. Taking into account dysregulated inflammatory activity in depression and the immunomodulatory role of lithium, we hypothesized that genes associated with inflammatory responses may be potential biomarkers of lithium action. We aimed to compare gene expression changes between the brain and the periphery after chronic lithium administration in an animal model of depression. Depressive behavior was induced by chronic mild stress protocol for 4 weeks. After 2 weeks, rats started to receive lithium (study group) or water (reference group). The control group were rats not exposed to stress. Amygdala, hippocampus, frontal cortex and peripheral blood were analyzed using whole transcriptome expression microarrays. Changes were confirmed with qPCR and ELISA assay. After 2 weeks of lithium administration, we observed significant changes in gene expression between amygdala and peripheral blood. Logistic regression analysis determined Alox15 expression as a predictor of lithium status, as its expression was tissue‑specific and increased in amygdala and decreased in blood. Analysis of serum ALOX15 protein revealed its upregulation after two‑week lithium administration. Our study suggests that lithium may have therapeutic potential in depressive behaviors. These results indicate immunomodulatory effect of lithium and that Alox15 may be a new potential marker of chronic lithium treatment.

Differential expression profile between amygdala and blood during chronic lithium treatment in a rat model of depression - a pilot study.

Lithium is a mood stabilizer widely used in the pharmacotherapy of bipolar disorder and treatment‑resistant depression. Taking into account dysregulated inflammatory activity in depression and the immunomodulatory role of lithium, we hypothesized that genes associated with inflammatory responses may be potential biomarkers of lithium action. We aimed to compare gene expression changes between the brain and the periphery after chronic lithium administration in an animal model of depression. Depressive behavior was induced by chronic mild stress protocol for 4 weeks. After 2 weeks, rats started to receive lithium (study group) or water (reference group). The control group were rats not exposed to stress. Amygdala, hippocampus, frontal cortex and peripheral blood were analyzed using whole transcriptome expression microarrays. Changes were confirmed with qPCR and ELISA assay. After 2 weeks of lithium administration, we observed significant changes in gene expression between amygdala and peripheral blood. Logistic regression analysis determined Alox15 expression as a predictor of lithium status, as its expression was tissue‑specific and increased in amygdala and decreased in blood. Analysis of serum ALOX15 protein revealed its upregulation after two‑week lithium administration. Our study suggests that lithium may have therapeutic potential in depressive behaviors. These results indicate immunomodulatory effect of lithium and that Alox15 may be a new potential marker of chronic lithium treatment.

A Longitudinal Study of the Effects of Lithium Treatment on Prefrontal and Subgenual Prefrontal Gray Matter Volume in Treatment-Responsive Bipolar Disorder Patients

Article AbstractObjective: Recent molecular, preclinical, and preliminary clinical studies suggest that the therapeutic effects of mood stabilizers may be mediated by modulating expression of potent neurotrophic and neuroprotective factors having the potential to reverse impairments of cellular resilience, reductions in brain volume, and cell death or atrophy. Our main goal was to investigate the potential clinical significance of these findings in relation to bipolar disorder. Method: The longitudinal effect of lithium on brain gray matter volume was investigated in well-characterized (DSM-IV criteria) bipolar depressed subjects (N = 28) at baseline (medication-free) and after lithium administration (4 weeks). Total brain gray matter, prefrontal gray matter, and left subgenual prefrontal gray matter volumes were determined using validated semiautomated segmentation and region of interest methodology. The study was conducted from November 1997 until April 2004 at Wayne State University School of Medicine, Detroit, Mich.Results: Significant increases in total brain gray matter volume in bipolar subjects were observed after 4 weeks of lithium administration (p = .0043). Moreover, regional analyses in the bipolar subjects revealed significant differences between responders (>50% decrease in Hamilton Depression Rating Scale total score) and nonresponders; only responders showed a significant increase in gray matter volume in the prefrontal cortex (p = .003) and an increase at trend level in the left subgenual prefrontal cortex volume (p = .0786). Conclusion: The increase in gray matter volume in these areas, which various neuroimaging and postmortem neuropathology studies have implicated in the neuropathophysiology of bipolar disorder, suggests that the observed effects may be linked to clinical response. The findings also support the notion that future treatments that more directly target molecules in critical central nervous system pathways that regulate cellular plasticity hold promise as novel, improved, long-term treatments for mood disorders as well as some neurodegenerative conditions, such as Alzheimer's disease.

A Longitudinal Study of the Effects of Lithium Treatment on Prefrontal and Subgenual Prefrontal Gray Matter Volume in Treatment-Responsive Bipolar Disorder Patients

Recent molecular, preclinical, and preliminary clinical studies suggest that the therapeutic effects of mood stabilizers may be mediated by modulating expression of potent neurotrophic and neuroprotective factors having the potential to reverse impairments of cellular resilience, reductions in brain volume, and cell death or atrophy. Our main goal was to investigate the potential clinical significance of these findings in relation to bipolar disorder. The longitudinal effect of lithium on brain gray matter volume was investigated in well-characterized (DSM-IV criteria) bipolar depressed subjects (N = 28) at baseline (medication-free) and after lithium administration (4 weeks). Total brain gray matter, prefrontal gray matter, and left subgenual prefrontal gray matter volumes were determined using validated semiautomated segmentation and region of interest methodology. The study was conducted from November 1997 until April 2004 at Wayne State University School of Medicine, Detroit, Mich. Significant increases in total brain gray matter volume in bipolar subjects were observed after 4 weeks of lithium administration (p = .0043). Moreover, regional analyses in the bipolar subjects revealed significant differences between responders (>50% decrease in Hamilton Depression Rating Scale total score) and nonresponders; only responders showed a significant increase in gray matter volume in the prefrontal cortex (p = .003) and an increase at trend level in the left subgenual prefrontal cortex volume (p = .0786). The increase in gray matter volume in these areas, which various neuroimaging and postmortem neuropathology studies have implicated in the neuropathophysiology of bipolar disorder, suggests that the observed effects may be linked to clinical response. The findings also support the notion that future treatments that more directly target molecules in critical central nervous system pathways that regulate cellular plasticity hold promise as novel, improved, long-term treatments for mood disorders as well as some neurodegenerative conditions, such as Alzheimer's disease. clinicaltrials.gov Identifier: NCT00870311.

Elektroenzephalographische und psychoexperimentelle Untersuchungen mit Lithium an gesunden Probanden

In previous experiments with lithium on normal volunteers, in whom plasma levels of 0.8 mmol/l after acute and 0.5-0.6 mmol/l during steady state after two weeks of lithium administration were obtained, we found slight effects on the awake EEG and psychological performance tests which could be interpreted as a decrease in vigilance and activation. The present study was designed to replicate these results with slightly higher plasma levels: 1 mval/l (acute), an 0.7-0.9 mval/l during steady state, in normal subjects selected according to strict EEG criteria. Besides quantitative pharmaco-EEG, the Zerssen scale for mood (Bf-S) and psychosomatic complaints (B-L) were applied; furthermore, subjective time estimation, the digit symbol test, flicker fusion frequency, and the pursuit rotor test were performed. After acute administration only a slight increase in psychosomatic complaints and a tendency towards increase in xxx-power in the EEG could be observed. Under chronic lithium treatment a significant increase in xxx-power and decrease in flicker fusion frequency in comparison to placebo were found. Tendencies for a decrease in performance were obtained by the digit symbol test and by the pursuit rotor test. The subjective time estimation 17 seconds as well as mood and psychosomatic complaints as measured by Bf-S and B-L did not change. The results of this trial confirm that lithium has negative effects on vigilance and activation. However, despite of higher plasma levels, the changes found in comparison to placebo were slight and discrete. Thus, in the routine test battery designed to describe and classify acute effects of classic psychotropic drugs such as 10 mg diazepam, 75 mg chlorpromazinc, 75 mg imipramine, or 20 mg dextroamphetamine, lithium does not induce unambiguous effects. Other test models are required to demonstrate specific psychic effects of lithium. In this context, appropriate criteria for selection of lithium sensitive subjects play an important role.

Effects of Lithium on Brain Glucose Metabolism in Healthy Men

Lithium is clinically available for the treatment of mood disorders. However, it has remained unclear how lithium acts on the brain to produce its effects. The aim of this study was to evaluate the effects of chronic lithium on human brain activity using positron emission tomography and clarify the correlation between brain activity changes and cognitive functional changes as induced by chronic lithium administration. A total of 20 healthy male subjects (mean age, 32 +/- 6 years) underwent positron emission tomographic scans with F-fluorodeoxyglucose and a battery of neuropsychological tests at baseline condition and after 4 weeks of lithium administration. Brain metabolic data were analyzed using statistical parametric mapping. Lithium increased relative regional cerebral glucose metabolism (rCMRglc) in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased rCMRglc in the right cerebellum and left lingual gyrus/cuneus. There was no difference in any of the variables of cognitive functions between the baseline condition and after chronic lithium administration. There was no correlation between rCMRglc changes in any of the brain regions and individual variable changes in any of the neuropsychological tests. The results suggest that the effects of chronic lithium are associated with increased activity in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased activity in the right cerebellum and left lingual gyrus/cuneus.

Prefrontal gray matter increases in healthy individuals after lithium treatment: A voxel-based morphometry study

The objective of this study was to test the hypothesis that 4 weeks of lithium administration would be associated with changes in brain gray and white matter volumes in healthy individuals. Thirteen right-handed healthy volunteers (6 females, mean age=25.9+/-10.0 years) were studied. 3D SPGR MRIs (TR=25 ms, TE=5 ms, slice-thickness=1.5 mm) were acquired using a 1.5 T GE Signa Imaging System, at baseline and after 4 weeks of lithium administration at therapeutically relevant doses. Optimized voxel-based morphometry (VBM) analyses were conducted. Left and right dorsolateral prefrontal cortex and left anterior cingulate gray matter volumes increased significantly following lithium administration. Total white matter volume was increased, whereas total brain volume and total gray matter volume were not significantly changed following 4 weeks of lithium. Lithium treatment resulted in prefrontal regional gray matter volume increases in healthy volunteers, as well as increases in total white matter volume. Whether these changes are mediated by neurotrophic/neuroprotective or osmotic effects remains unknown.

Lithium effects on brain glutamatergic and GABAergic systems of healthy volunteers as measured by proton magnetic resonance spectroscopy

Lithium is a first-line medicinal treatment for acute bipolar disorder and is also used prophylactically in manic depressive illnesses; however, its mechanism of action is still largely unknown. Animal and human studies have suggested that lithium modulates glutamatergic and GABAergic neurotransmissions. The aim of this study is to investigate the effects of lithium on brain glutamate (Glu), glutamine (Gln), and γ-aminobutyric acid (GABA) levels in healthy individuals using proton magnetic resonance spectroscopy ( 1H-MRS). In vivo 3 Tesla 1H-MRS was performed on the anterior cingulate cortex and bilateral basal ganglia initially and after two weeks of lithium administration on 8 healthy male subjects who had a mean age of 34.9 years. After two weeks of lithium administration, Gln significantly decreased in the left basal ganglia and showed a decreasing trend in the right basal ganglia. Additionally, Glu + Gln (Glx) significantly decreased in the right basal ganglia and showed a decreasing trend in the left basal ganglia. Glu did not significantly change in any of the three tested areas, and GABA exhibited no significant change after the lithium administration when measured in the anterior cingulate cortex and left basal ganglia. This study is the first to demonstrate that subchronic lithium treatment decreases Gln and Glx levels in the bilateral basal ganglia of healthy individuals. Our finding might suggest that the decrease of Glx levels is associated with the pharmacological actions of subchronic lithium treatment.

Molecular Cloning of a Novel Isoform of Diphosphoinositol Polyphosphate Phosphohydrolase:: A Potential Target of Lithium Therapy

The mechanisms underlying the therapeutic effects of lithium are largely unknown but may involve progressive adaptive alterations at the level of gene expression. Using differential display PCR, we identify a novel cDNA fragment, the expression of which was increased in the rat frontal cortex after 5 weeks of lithium administration. A full-length cDNA (2954-nt) was cloned by arrayed cDNA library screening, and sequencing of the clone revealed an open reading frame of 537-bp encoding a 179-residue protein. Amino acid sequence comparisons revealed that our clone is a member of the Nudix hydrolase family, with the highest percentage of homology (95%) being with a subtype of human diphosphoinositol polyphosphate phosphohydrolase, hDIPP2. Northern blot analysis revealed that chronic lithium treatment significantly increased rDIPP2 mRNA levels in frontal cortex, but not in hippocampus, midbrain, and cerebellum. The effect of lithium on rDIPP2 mRNA expression was not shared by two other anticonvulsant mood stabilizers, carbamazepine and valproate. Time-course studies showed that 1-week of lithium had no effect on rDIPP2 mRNA abundance in the frontal cortex. Our results suggest that DIPP2 may represent a biologically relevant target of lithium therapy, further supporting the notion that abnormalities in inositol phosphate metabolism may be significant in the pathophysiology and pharmacotherapy of bipolar disorder.

Possible inhibitory effect of lithium on peripheral conversion of thyroxine to triiodothyronine

The effect of lithium on thyroid function was studied in 18 neuroleptic-treated male chronic schizophrenic in-patients. Lithium carbonate was administered for 8 weeks at a dosage giving a mean serum level of 0.79 mmol/l. Blood was obtained just before and after 8 weeks of lithium administration to determine the serum free thyroxine (free T4) levels, free triiodothyronine (free T3) levels and thyrotropin (TSH) levels. Overall, free T4 and TSH levels significantly increased whereas free T3 levels did not change. Two (11%) patients had abnormally increased free T4 levels and abnormally decreased free T3 levels after 8 weeks of lithium administration. These findings suggest that lithium may inhibit the peripheral conversion of free T4 to free T3 in some susceptible patients.

Effects of chronic lithium treatment on platelet PKC isozymes in Alzheimer's and elderly control subjects

Patients with Alzheimer's disease (AD) have been reported to have abnormalities in peripheral cells similar to some of those found in the brain, including decreased levels of protein kinase C (PKC) in fibroblasts. Since increasing evidence suggests that lithium affects PKC function, we investigated the effects of 3 weeks of lithium administration on the immunolabeling of 4 PKC isozymes (α, β, ε, and ζ) in particulate and soluble fractions from platelets of 7 patients with probable AD and 6 age-matched controls. AD patients had significantly less particulate or membrane-associated PKC ζ than normals during the placebo phase ( P < 0.003). After 3 weeks of lithium treatment, AD patients had significantly less membrane-associated PKC α ( P < 0.002), ε ( P < 0.003), and ζ ( P < 0.001) than normals. This is the first report of a difference in PKC in blood cells between AD and control subjects. These findings appear to indicate that some PKC isozymes may be differentially regulated in AD versus elderly controls, at least as evidenced in this peripheral cellular system.

Effects of chronic chlorpromazine or lithium administration on ageing-related lipopigment in rat Purkinje neurones

Ageing-related accumulation of neuronal lipopigment is considered to be debris from processes of renewal of cellular constituents, but can also reflect cell damage and certain diseases. Chlorpromazine (an example of a class of drug chronically administered in psychiatric practice) has been reported to reduce neuronal lipopigment accumulation, and the present study investigated the effects of 28 weeks of chlorpromazine administration on lipopigment in rat Purkinje neurones. The effects of 26 weeks of lithium administration (also chronically administered in psychiatric practice) were also studied. Lipopigment was identified by fluorescence microscopy and the area enclosed by an outline of each discrete region of lipopigment was measured. While lithium administration was not associated with significant changes in lipopigment variables, chlorpromazine administration was associated with a significant (p=0.001) reduction in the number of discrete lipopigment regions and with significant (p=0.001) differences in the numbers of discrete lipopigment regions in various size categories. The findings are similar to those associated with the administration of acetyl-L-carnitine (which has been reported to reduce some morphological and behavioural associations of brain ageing) and are compatible with a reduction in the rate of lipopigment formation. This could reflect an adverse effect of chlorpromazine administration (i.e. reduced functional activity of neurones) or a beneficial effect (i.e. a reduction in ageing-related changes).

In vivo evidence that lithium inactivates Gi modulation of adenylate cyclase in brain.

In vivo microdialysis of cyclic AMP from prefrontal cortex complemented by ex vivo measures was used to investigate the possibility that lithium produces functional changes in G proteins that could account for its effects on adenylate cyclase activity. Four weeks of lithium administration (serum lithium concentration of 0.85 +/- 0.05 mM; n = 11) significantly increased the basal cyclic AMP content in dialysate from prefrontal cortex of anesthetized rats. Forskolin infused through the probe increased dialysate cyclic AMP, but the magnitude of this increase was unaffected by chronic lithium administration. Inactivation of the inhibitory guanine nucleotide binding protein Gi with pertussis toxin increased dialysate cyclic AMP in control rats, as did stimulation with cholera toxin (which activates the stimulatory guanine nucleotide binding protein Gs). The effect of pertussis toxin was abolished following chronic lithium, whereas the increase in cyclic AMP after cholera toxin was enhanced. In vitro pertussis toxin-catalyzed ADP ribosylation of alpha i (and alpha o) was increased by 20% in prefrontal cortex from lithium-treated rats, but the alpha i and alpha s contents (as determined by immunoblot) as well as the cholera toxin-catalyzed ADP ribosylation of alpha s were unchanged. Taken together, these results suggest that chronic lithium administration may interfere with the dissociation of Gi into its active components and thereby remove a tonic inhibitory influence on adenylate cyclase, with resultant enhanced basal and cholera toxin-stimulated adenylate cyclase activity.

The mechanisms of action of lithium. I. Effects on serotoninergic and noradrenergic systems in normal subjects.

The effects of 2 weeks of lithium carbonate administration at therapeutic plasma levels were examined in 11 normal volunteers. Serotoninergic function before and after lithium administration was assessed using low-dose intravenous clomipramine hydrochloride challenge, while urinary and plasma metabolites of norepinephrine (NE) were used to assess noradrenergic systems. Long-term lithium administration in normal subjects did not significantly or consistently enhance serotonin-mediated neuroendocrine responses but did increase measures related to neuronal release of NE. No statistically significant effects of lithium on prolactin, corticotropin, or cortisol responses to serotoninergic challenge could be detected. The probability of a type II error was assessed, and a doubling of prolactin level was unlikely to have been missed, although more modest increases (less than 75%) could have been overlooked. After 2 weeks of lithium administration, there were significant increases in 24-hour urinary excretion of NE, normetanephrine, and fractional NE release, compatible with increased neuronal release of NE and a lithium-induced subsensitivity in alpha 2-adrenergic receptor function. These changes were not statistically significant after 1 week of administration, suggesting that increased NE release is characteristic of long- rather than short-term lithium administration. Since previous reports have demonstrated enhanced prolactin responses after short- but not long-term lithium use, the present study points to temporal specificity in lithium's effects on both serotoninergic and noradrenergic function. Lithium's effects on NE release were consistent but small (a 16% increase), while its effects on serotoninergic responses were larger (a 50% increase in prolactin responses) but quite inconsistent, suggesting that neither of these systems is the primary site of action of lithium.

Kinetics of erythrocyte lithium—sodium countertransport in patients with affective illness before and during lithium therapy

Previous investigations have elucidated an erythrocyte lithium-sodium countertransport (LSC) system as the primary mechanism for extruding lithium from the cell, and this activity has been described in terms of Michaelis-Menten kinetics. In most clinical studies the maximum velocity ( V max) of the LSC has been measured by estimating the rate of lithium efflux from lithium-loaded cells. To date, few studies have examined whether the affinity ( K m) of the LSC for lithium might be altered in patients with affective disorders. In the present study we examined LSC kinetic parameters ( V max, leak K m, and in vitro lithium ratio) at baseline in 80 patients with affective disorder and 25 healthy control subjects, and after 6 weeks of lithium administration in 33 of the patients. No differences in V max were observed between any patient and control group, although V max was significantly lower in unipolar depressed men compared to bipolar men ( P=0.043). The affinity ( K m) of the transport ‘carrier’ for lithium did not differentiate between patient and control groups. Chronic lithium administration caused a decreased V max in bipolar men ( P=0.015), an increase in the in vitro lithium ratio in bipolar men ( P=0.002) and bipolar women ( P=0.002), and a marginal increase in K m in bipolar men ( P=0.08) and bipolar women ( P=0.06). Although the present data do not demonstrate an underlying difference for K m between affectively ill patients and controls, they do indicate a decrease in the affinity of the transport ‘carrier’ for lithium after chronic lithium administration.

The effect of chronic lithium administration on dopamine metabolism in rat striatum

Striatal dopamine and its metabolites were studied in rats given lithium chloride in the diet. Results showed an increase in homovanillic acid and 3,4-dihydroxyphenylacetic acid levels but no significant change in dopamine concentration after 3 weeks of lithium administration. There was no change in tyrosine hydroxylase activity after 1, 2, and 3 weeks treatment. The results indicate an increase in the release and turnover of dopamine in the lithium-treated animals.

Leukocytosis During Lithium Treatment

An increase in circulating leukocytes accompanied lithium treatment in 28 consecutively studied manic-depressive patients. Acutely manic patients showed the most marked changes and maintained leukocyte counts of 10,000 to 14,000 during the first two to four weeks of lithium administration. Leukocyte counts returned to pre-lithium levels within one week after discontinuation of the drug. In 11 patients receiving lithium for longer periods the elevation in white cell count persisted throughout treatment.