Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LITHIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources

Lithium stimulates accumulation of second-messenger inositol 1,4,5-trisphosphate and other inositol phosphates in mouse pancreatic minilobules without inositol supplementation.

Previous studies showed that lithium, beginning at therapeutic plasma concentrations in the treatment of manic depression, increased the accumulation of second-messenger inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] in cerebral cortex slices of guinea pig and rhesus monkey [Lee, Dixon, Reichman, Moummi, Los and Hokin (1992) Biochem. J. 282, 377-385; Dixon, Lee, Los and Hokin (1992) J. Neurochem. 59, 2332-2335; Dixon, Los and Hokin (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 8358-8362]. These studies have now been extended to a peripheral tissue, mouse pancreatic minilobules. In the presence of carbachol, concentrations of lithium from 1 to 20 mM sharply and progressively increased the accumulation of Ins(1,4,5)P3 and inositol 1,3,4,5-tetrakisphosphate, followed by a decrease. Assay of these inositol polyphosphates by either the prelabelling technique or mass assay gave similar results. Atropine quenching of cholinergically stimulated pancreatic minilobules led to a rapid disappearance of Ins(1,4,5)P3. This disappearance was impeded by lithium. This suggested that the lithium-induced elevation in Ins(1,4,5)P3 was due to inhibition of the 5-phosphatase and, on the basis of the markedly elevated concentrations of inositol 1,3,4-trisphosphate [Ins(1,3,4)P3] and inositol 1,4-bisphosphate in the presence of lithium, probably by feedback inhibition by these latter two compounds. An additional mechanism, i.e. a stimulatory effect of lithium on phospholipase C, cannot, however, be ruled out. The other reaction product of phospholipase C, inositol cyclic 1:2,4,5-trisphosphate, also increased in the presence of lithium. This may also be due to inhibition of the 5-phosphatase, which is the exclusive mechanism for removal of this compound. The effects of lithium on the accumulation of other inositol phosphates paralleled that of Ins(1,4,5)P3, with the exception of inositol 3,4-bisphosphate, which decreased. This was presumably due to the inhibition of Ins(1,3,4)P3 1-phosphatase by lithium. Unlike mouse cerebral cortex slices [Lee, Dixon, Reichman, Moummi, Los and Hokin (1992) Biochem. J. 282, 377-385], inositol supplementation was not required to demonstrate lithium-stimulated Ins(1,4,5)P3 accumulation in mouse pancreatic minilobules. This indicates that inositol depletion sufficient to impair lithium-stimulated Ins(1,4,5)P3 accumulation does not occur in mouse pancreatic minilobules, even though an elevation of cytidine diphosphodiacylglycerol occurred, indicating some inositol depletion due to lithium. Elevation of Ins(1,4,5)P3 by lithium may be a general phenomenon in the central nervous system and peripheral tissues under non-rate-limiting concentrations of inositol.

Animals↗

Effects of lithium on saccadic eye movements in healthy subjects in a ten-day double-blind placebo-controlled cross-over pilot study.

INTRODUCTION: Although previous studies have shown that lithium modifies eye movements or psychomotor speed, no studies have ever explored the predictive saccades or memory guided saccades during lithium administration. We took the objective to determine the influence of lithium in pseudo-random, predictive or memory-guided saccades in healthy subjects with a view to detect reduced psychomotor speed, inability to anticipate incoming events, or working memory deficits. METHODS: A ten day lithium-placebo randomized double-blind cross-over pilot study was carried out with 12 healthy male volunteers. The cognitive assessment included pseudo-random, predictive and memory guided saccades before and after lithium and placebo periods. A biological assay substantiated the lithium effect on TSH and thyroid hormones. RESULTS: There was no change in pseudo-random or memory guided saccades when comparing lithium or placebo administration. However the ratio of anticipated saccades decreased under the lithium sequence while it remained stable under placebo. Also, subjects having lithium serum levels of > 0.5 meq/l had longer latencies in anticipated saccades. CONCLUSION: The findings do not support a major effect of lithium on alertness or on working memory, although the dosage and duration of lithium was sufficient to modify TSH blood level. Nevertheless, lithium treatment was associated with decreased anticipation in predictive saccades, suggesting this could reflect a reduced ability to anticipate quick motor movements and could be related to the well-known effect of lithium as an anti-impulsive medication.

Adult↗

Lithium inhibits cell cycle progression and induces stabilization of p53 in bovine aortic endothelial cells.

Lithium affects development of various organisms and cell fate through the inhibition of glycogen synthase kinase-3 beta and induction of the Wnt/beta-catenin signaling pathway. In this study, we investigated the effects of lithium on primary bovine aortic endothelial cells (BAEC). Lithium treatment of BAEC induced beta-catenin stabilization but failed to activate the transcriptional activity of the beta-catenin/T-cell factor complex. Lithium caused a sustained G(2)/M cell cycle arrest without affecting cell viability. Reversibility of this cell cycle arrest occurred up to 3 days after treatment but was reduced thereafter. Lithium-treated BAEC exhibited a senescent-like morphology with an increase in cells positive for the senescence-associated-beta-galactosidase activity. Lithium also increased the expression of p21(Cip), a cyclin-dependent kinase inhibitor, both at the protein and RNA levels. No change in p21(Cip) mRNA stability was observed, whereas the transcriptional activity of a p21(Cip) promoter-luciferase construct containing p53 binding sites was increased after lithium treatment. Furthermore, lithium caused increased transcription of a reporter gene under the control of a promoter containing the p53 consensus binding sites both in transiently transfected BAEC and in a stably transfected fibroblast cell line. Lithium caused accumulation of p53 protein in BAEC without affecting p53 mRNA levels. Finally, up-regulation of p21(Cip) in response to lithium did not occur in mouse embryonic fibroblasts that were null for p53 alleles, confirming the dependence on a p53 pathway for this lithium effect. These findings demonstrate for the first time that lithium induces also stabilization of the tumor suppressor p53 and reveal a new mechanism that may contribute to the neuroprotective effects of lithium.

Animals↗

Lithium treatment and kidney function. A follow-up study of 237 patients in long-term treatment.

Two years after a survey of the kidney function in 237 patients given long-term lithium treatment the patients were invited for reexamination. Of 184 patients who came for the reexamination 147 had continued lithium treatment; in 37 patients the treatment had been discontinued. The lithium-treated patients were compared with a group of 68 manic-depressive patients who were about to be given prophylactic lithium treatment but who had not yet started. Neither the patients who continued nor the patients who had discontinued lithium showed any deterioration of glomerular filtration rate as assessed through determination of the 24-h creatinine clearance and the serum creatinine concentration; mean values in the lithium-treated patients were the same as mean values in patients not yet given lithium. Impairment of renal water reabsorption, revealed by increased 24-h urine volume and decreased urine osmolality after DDAVP, had progressed in the patients who continued lithium treatment, and multiple regression analysis revealed the duration of treatment and the serum lithium level to be significant predictor variables. In the patients who had discontinued lithium the changes in renal water handling had decreased. The urine volume was the same as that found in the patients not yet given lithium; maximum urine osmolality had not become fully normalized. Side effects such as thirst, nycturia, tremor, diarrhoea, oedema, and weight gain were found with the same frequency at the second as at the first examination in the patients who had continued lithium. In the patients who had discontinued lithium they were infrequent or absent.

Adult↗

Myocardial changes in rats with lithium-induced uraemia.

The possible effects of lithium on myocardial morphology were studied at the light-microscopic level in three different rat models: (i) rats with chronic renal failure due to lithium administration for 8-16 weeks after birth, (ii) normal, adult rats treated with lithium for 16 weeks, and (iii) new-born rats exposed to lithium in their prenatal life. Morphological changes were found in 57% of the male rats with lithium-induced uraemia after lithium administration for 16 weeks postnatally. The changes comprised myocytic degeneration and necrosis associated with infiltration of lymphocytes, histiocytes and plasma cells. This morphological picture is different from the myocardial changes associated with chronic renal failure. Male rats with chronic uraemia after withdrawal of lithium 8 weeks postnatally showed no myocardial changes after 16 weeks. Also, male rats with normal renal function had no myocardial changes after 16 weeks on lithium, but these rats had a significantly lower plasma level of lithium than the lithium-uraemic rats (0.8 vs. 1.4 mmol/l). It is suggested that myocarditis was a consequence of persistent high plasma levels of lithium maintained in the lithium-uraemic rats and that cardiotoxic effects of lithium may be potentiated by concomitant renal failure.

Animals↗

Lithium inhibits morphogenesis of the nervous system but not neuronal differentiation in Xenopus laevis.

Xenopus embryos treated with 100 mM-lithium from the 2- to 4-cell stage to the early blastula stage (4h) failed to neurulate and developed without a discernible anteroposterior axis. The internal structure of defective embryos was grossly disorganized, but immunohistochemical staining with cell-type-specific antibodies revealed differentiated nerve and muscle cells. Quantitative assay in tissue cultures from control and acutely abnormal lithium-treated embryos showed that neural differentiation was enhanced and muscle differentiation unaffected. The embryos took up about 0.5 mM-lithium at threshold, maximal effects resulted at 2-3 mM. Most of the lithium was extruded from the cells into the blastocoel fluid, where lithium reached 17 mM. The threshold intracellular concentration was about 150 microM. Lithium uptake rose steeply as the osmotic/ionic strength of the bathing medium increased. Sodium, potassium and lithium were equally able to increase the permeability of the embryo. However, sodium ions enhanced, while potassium ions interfered with, the uptake of lithium. Treatment with lithium at progressively later stages reduced the developmental defects and neural differentiation returned to normal levels. The uptake of lithium did not decline concomitantly. We conclude that lithium does not inhibit neural induction, but interferes with dorsal patterning. The sensitivity of the embryo to lithium is determined by developmental stage. The very low, effective intracellular concentrations may be important in understanding the mechanism of lithium-generated defects.

Animals↗

Increased lithium dose requirement in a hyperglycemic patient.

OBJECTIVE: To report a case of apparent increased lithium clearance in a patient with persistent hyperglycemia. METHODS: Lithium doses, blood glucose concentrations, and lithium plasma concentrations were evaluated in a patient during a 53-day inpatient admission for exacerbation of bipolar disorder. The lithium dose required to increase the lithium plasma concentration by 0.1 mEq/L was computed from the lithium dose and corresponding lithium plasma concentration. This value was correlated with the blood glucose concentration. RESULTS: A plot of the lithium dose required to increase the lithium plasma concentration by 0.1 mEq/L versus the blood glucose concentration exhibited a direct linear relationship (r2 = 0.62). This plot indicates that higher lithium doses are needed during hyperglycemic states compared with euglycemic states to achieve equivalent plasma concentrations. CONCLUSIONS: Glycosuria associated with hyperglycemia induces an osmotic diuresis that increases the renal clearance of lithium, necessitating higher lithium doses to maintain therapeutic lithium plasma concentrations.

Adult↗

Lithium and the kidney: an updated review.

Despite the availability of alternative agents, lithium continues to be the standard against which all mood stabilisers, prescribed for acute and maintenance treatment of bipolar (and, to a lesser extent, unipolar) mood disorders, are compared. As a medication often used on a maintenance basis for a lifelong disorder, the potential for lithium to cause long term organ toxicity has generated appropriate concern. Foremost among these concerns are its renal effects. Lithium adversely affects renal tubular function, causing polyuria secondary to a deficit in urine concentrating ability. This effect is probably progressive for the first decade of lithium therapy, i.e. it correlates with duration of lithium therapy. Although this effect of lithium is probably functional and reversible early in treatment, it may become structural and irreversible over time. In contrast, the effect of lithium on glomerular function is not progressive. Conclusions in this area are hampered by the evidence that patients with psychiatric disorders who are not receiving lithium also show defects in certain aspects of renal function. Despite the generally sanguine data on glomerular function, a very small group of patients may develop renal insufficiency due to lithium (possibly in conjunction with other somatic factors) in the form of interstitial nephritis. However, for the vast majority of patients, the renal effects of lithium are benign. Current strategies for minimising the renal effects of lithium include: (i) assiduously avoiding episodes of renal toxicity; (ii) monitoring serum lithium concentrations in order to achieve optimal efficacy at the lowest possible concentration; (iii) monitoring serum creatinine levels on a yearly basis, getting further medical evaluation when the serum creatinine level consistently rises above 140 mmol/L (1.6 mg/dl); and (iv) possibly administering lithium once a day.

Bipolar Disorder↗

Clinical relevance of drug interactions with lithium.

Although lithium continues to be regarded as the treatment of choice for bipolar disorders, the clinical use of this mood stabiliser is associated with an extremely narrow therapeutic range. Relatively minor increases in serum concentrations may induce serious adverse sequelae, and concentrations within the therapeutic range may result in toxic reactions. The safety of combining lithium with other medications, therefore, is a major concern, and extensive clinical experience has served to identify several significant drug interactions. Lithium removal from the body is achieved almost exclusively via renal means. As a result, any medication that alters glomerular filtration rates or affects electrolyte exchange in the nephron may influence the pharmacokinetic disposition of lithium. Concomitant use of diuretics has long been associated with the development of lithium toxicity, but the risk of significant interactions varies with the site of pharmacological action of the diuretic in the renal tubule. Thiazide diuretics have demonstrated the greatest potential to increase lithium concentrations, with a 25 to 40% increase in concentrations often evident after initiation of therapy. Osmotic diuretics and methyl xanthines appear to have the opposite effect on lithium clearance and have been advocated historically as antidotes for lithium toxicity. Loop diuretics and potassium-sparing agents have minor variable effects. Nonsteroidal anti-inflammatory drugs (NSAIDs) have also been associated with lithium toxicity, although the relative interactive potential of specific NSAIDs is difficult to determine. Small prospective studies have demonstrated large interindividual differences in lithium clearance values associated with different NSAIDs. A growing body of evidence also suggests that ACE inhibitors may impair lithium elimination, but further investigations are needed to identify patients at risk. Anecdotal reports have linked numerous medications with the development of neurotoxicity without an apparent effect on the pharmacokinetic disposition of lithium. Antipsychotics, anticonvulsants and calcium antagonists have all be implicated in a sufficient number of case reports to warrant concern. As these medications have all been commonly coadministered with lithium, the relative risk of serious interactions appears to be quite low, but caution is advised.

Angiotensin-Converting Enzyme Inhibitors↗

Efficacy and mechanisms of action of lithium augmentation in refractory major depression.

Lithium augmentation refers to the addition of lithium to an antidepressant in the acute treatment phase of patients with depressive episodes who have failed to respond satisfactorily to treatment with antidepressant monotherapy. This article reviews the clinical evidence and hypotheses on the mode of action of lithium augmentation. For this purpose, studies were identified by searching Medline and by scanning the references of published reviews and standard textbooks. With regard to efficacy, 28 prospective studies (with a total of 838 depressed patients) were identified. The majority of randomized controlled trials has demonstrated substantial efficacy of lithium augmentation. A recent meta-analysis including only double-blind, placebo-controlled trials (N = 9) provided firm evidence that lithium augmentation has a statistically significant effect on response rate compared to placebo, and showed that lithium augmentation should be administered for at least 2 weeks to allow assessment of the patient's response. A recent double-blind, placebo-controlled trial revealed that responders to lithium augmentation should be maintained on the lithium-antidepressant combination for a minimum of 12 months. From animal studies there is robust evidence that lithium augmentation increases serotonin (5-HT) neurotransmission, possibly through a synergistic action of lithium and the antidepressant on brain 5-HT pathways. Neuroendocrine studies in humans on the effects of lithium augmentation on the HPA system showed an unexpected and marked increase in the ACTH and cortisol response in the combined dexamethasone/CRH test. These results are in contrast to the established decline of HPA system activity during treatment with antidepressants. In conclusion, lithium is the foremost and most well-documented augmentation strategy in refractory depression. In international treatment guidelines and algorithms, lithium augmentation is considered a first-line treatment strategy for patients with a major depressive episode who do not adequately respond to standard antidepressant treatment.

Animals↗

Study of the effect of lithium on lymphokine-activated killer cell activity and its antitumor growth.

The in vitro effect of lithium on lymphokine-activated killer cell (LAK) activity and its in vivo antitumor growth were observed. LAK activity was enhanced when LiCl was added during LAK cell induction, and this enhancement was observed both in human peripheral blood mononuclear cell and in mouse splenocytes used as LAK precursors. Cholera toxin, which can increase intracellular levels of cAMP, decreased LAK cell activity. However, lithium partially reversed this inhibitory effect, indicating that lithium increased LAK cell activity by decreasing cAMP levels. D-Sphingosine, an inhibitor of protein kinase C, and EGTA, a calcium chelator, both inhibited the LAK cell activity. However, their inhibitory effects could not be reversed by lithium because lithium was added in the culture in combination with one of these inhibitors during LAK cell induction. By using slot blot analysis, the effect of lithium on the expression of tumor necrosis factor-alpha mRNA of LAK cells was analyzed. Lithium increased the level of tumor necrosis factor-alpha mRNA when both lithium and interleukin 2 were added to induce LAK cells. The in vivo antitumor effect of lithium has also been studied. Using a mouse melanoma experimental model, the effect of lithium on tumor growth was also observed. Both lithium alone and interleukin 2/LAK had an antitumor effect, whereas the treatment of interleukin 2/LAK in combination with lithium had the strongest inhibitory effect on tumor growth, since this treatment resulted in reduction of tumor size and prolongation of survival in tumor-bearing mice. Therefore, it is hopeful that lithium can be used as a new immunomodulator for cancer immunotherapy and immune diseases.

Animals↗

Appropriateness of therapeutic drug monitoring for lithium.

OBJECTIVE: Evaluate the appropriateness of therapeutic drug monitoring (TDM) for lithium. MATERIAL AND METHOD: A retrospective chart review of all patients who received lithium for treatment of psychiatric disorders between January 2004 and October 2005 was done. The present study was investigated in a psychiatric hospital in Thailand Based on detailed chart review, the appropriateness of TDM utilization comprised of three aspects, i.e., the indication of TDM request, the time of blood sample taking in relation to the medication process, and the clinical applications of the reported serum lithium levels, were evaluated. The Morecambe Bay Shared Care Guideline 2003 was modified and used as criteria for evaluation. Altogether 91 serum lithium samples were measured among 60 patients. RESULT: In 66 (72.5%) of requests, clear indications for lithium TDM were recorded i.e., initiation therapy 41.8%, suspected toxicity 15.4%, patient compliance assessment 5.5%, after regimen changes 5.5%, and therapeutic failure 4.4%. Routine tests without specified indications were found in the remainder (27.5%), all were in-patients, which pointed to potentially redundant use. The time of sample taking was recorded in 37 (40.6%) of blood samples, all were taken from in-patients, after steady state had been reached. These data for out-patients were not recorded, except one noted that blood sample was drawn after the patient had not received lithium for four days. Serum lithium levels were reported in 83 (91.2%) samples. Of these, 37 (44.6%) were out of therapeutic range, and only 12 required dosage alterations. The evaluation demonstrated somewhat inappropriate use of reported lithium levels. Dose changes were done in some patients who required dosage adjustment. Among 14 toxicity-suspected patients, nine actually had serum lithium levels exceeding the therapeutic range. Of these, only one patient was subsequently switched to a reduced dose, three patients were discontinued while five patients were prescribed the pre-TDM doses. Similarly, in five toxicity-suspected patients whose serum lithium levels were below therapeutic range, lithium was discontinued in three patients and no dosage alteration, which was considerably acceptable, in two patients. The doses were increased in three out offour inadequately controlled patients whose serum lithium was lower than the therapeutic range. Overall, in only 33 (36.3%) requests was TDM performed appropriately according to the indication, sampling time and subsequent dose adjustment. CONCLUSION: The findings indicate the need to improve the utilization of TDM for lithium. Education for hospital personnel on appropriateness of serum sample collection, interpretation, and proper use of serum drug levels is encouraged. Development of a request form containing essential data, such as indication for TDM, current drug dosing regimen, time of last dose, patient compliance, test results and interpretations and clinical decision made, can help optimize TDM use and reduce unnecessary costs.

Adolescent↗

Lithium interaction with sulindac and naproxen.

The interaction of lithium with sulindac and naproxen was studied in six sulindac-treated and seven naproxen-treated patients admitted to a geropsychiatry ward. Patients under a steady state lithium level received lithium for 3 days, then lithium + sulindac (300 mg/day) or naproxen (750 mg/day) for 6 days, and then lithium alone for 5 days. Sulindac failed to affect serum lithium levels and lithium clearance. The results with naproxen showed marked interindividual variations ranging from no increase to a 41.9% increase in serum lithium levels within 5 days. There was a corresponding decrease in lithium clearance in naproxen-treated patients. Patients undergoing lithium therapy might need a reduction of their lithium dosage following naproxen administration. More frequent serum lithium level determinations are required following initiation of naproxen therapy until the magnitude of the lithium-naproxen drug interaction can be adequately assessed in a given individual.

Aged↗

[Erythrocyte/plasma ratio of lithium. Determination method and individual stability].

Lithium is a very efficient drug for the treatment of maniac-depressive psychosis, but its therapeutic index is narrow. Moreover, even with lithium plasmatic concentrations in the therapeutic range, some patients showed toxic signs when others seemed not to be efficiently treated. The measurement of erythrocyte lithium concentration might provide a more rational method than the measurement of plasma lithium for monitoring the course of lithium therapy, since the mechanisms of lithium transfer across red blood cells resemble those for neurons. Toxic effects could then be related to high lithium erythrocyte concentrations or a high erythrocyte/plasma lithium ratio (EPR). The intracellular lithium concentration depends mainly on the Li(+)-Na+ countertransport, which is genetically determined. We wondered therefore whether the EPR is a specific characteristic of each patient and how long it requires to stabilise when lithium therapy is started. The EPR was determined by directly measuring the plasma and erythrocyte concentrations with a carefully standardised assay (lithium carbonate administered at 7 pm, blood sample taken at 7 am the next day). Potassium edetate was preferred as anticoagulant to sodium heparinate, which gave an overestimation of EPR. Plasma trapped in the red cell column, with polyfructosan as marker, was found to average 4% in our assay conditions (centrifugation at 3,200 g, 15 min, 4 degrees C). This standardised assay makes it possible to determine the EPR very accurately with an inter-assay variation coefficient of about 2.4%. Following the start of lithium therapy, the EPR stabilised very quickly, mainly within two days (three out of four patients), at a time when lithium erythrocyte and plasma concentrations were still increasing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Comparison of simultaneous administration of lithium with L-NAME or L-arginine on morphine withdrawal syndrome in mice.

Due to the claim that chronic administration of lithium or L-N(G)-nitroarginine methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor reduces morphine withdrawal syndrome, the effects of chronic administration of lithium, L-NAME, or L-arginine (L-Arg), a precursor of NO, alone or co-administration of lithium with L-Arg or L-NAME, on naloxone-precipitated withdrawal syndrome and physical dependence development to morphine in mice chronically treated with morphine, were evaluated. Morphine dependency was induced by the intraperitoneal injection (i.p.) of morphine (10 mg/kg), once daily for 7 days. Physical dependence to morphine was observed by precipitating an abstinence syndrome with naloxone (2 mg/kg, i.p.). Chronic administration of L-NAME (10 mg/kg, i.p., once daily, for 7 days after 10 days of receiving only tap water and food prior to naloxone), decreased all withdrawal signs significantly, while L-Arg (200 mg/kg, as above) increased only some withdrawal signs significantly in morphine-dependent mice. Chronic administration of lithium (600 mg/kg, in drinking water) alone or co-administration of lithium (as above) with L-NAME (10 mg/kg) or L-Arg (200 mg/kg, i.p., once daily) for 7 days after 10 days of receiving only lithium (as above) and food, decreased all withdrawal signs and physical dependence significantly in morphine-dependent mice. The results obtained indicate that co-administration of L-NAME with lithium increases the effect of lithium or L-NAME alone, on withdrawal signs, but this increase is not significantly different as compared to chronic lithium or L-NAME administration alone; while co-administration of L-Arg with lithium decreases the effects of lithium on withdrawal signs and this decrease is not significant as compared to chronic lithium administration alone. These findings indicate that nitric oxide may be involved in modulation of naloxone-induced withdrawal syndrome, and treatment with lithium could have some effect on this system. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗

Correlation between the 6Li,15N coupling constant and the coordination number at lithium.

The 6Li,15N coupling constants of lithium amide dimers and their mixed complexes with n-butyllithium, formed from five different chiral amines derived from (S)-[15N]phenylalanine, were determined in diethyl ether (Et2O), tetrahydrofuran (THF) and toluene. Results of NMR spectroscopy studies of these complexes show a clear difference in 6Li,15N coupling constants between di-, tri- and tetracoordinated lithium atoms. The lithium amide dimers with a chelating ether group exhibit 6Li,15N coupling constants of approximately 3.8 and approximately 5.5 Hz for the tetracoordinated and tricoordinated lithium atoms, respectively. The lithium amide dimers with a chelating thioether group show distinctly larger 6Li,15N coupling constants of approximately 4.4 Hz for the tetracoordinated lithium atoms, and the tricoordinated lithium atoms have smaller 6Li,15N coupling constants, approximately 4.9 Hz, than their ether analogues. In diethyl ether and tetrahydrofuran, mixed dimeric complexes between the lithium amides and n-butyllithium are formed. The tetracoordinated lithium atoms of these complexes have 6Li,15N coupling constants of approximately 4.0 Hz, and the 6Li,15N coupling constants of the tricoordinated lithium atoms differ somewhat, depending on whether the chelating group is an ether or a thioether; approximately 5.1 and approximately 4.6 Hz, respectively. In toluene, mixed trimeric complexes are formed from two lithium amide moieties and one n-butyllithium. In these trimers, two lithium atoms are tricoordinated with 6Li,15N coupling constants of approximately 4.6 Hz and one lithium is dicoordinated with 6Li,15N coupling constants of approximately 6.5 Hz.

Journal Article↗

Lithium treatment and thyroid abnormalities.

BACKGROUND: Although the interactions between lithium treatment and thyroid function have long been recognised, their clinical relevance is still controversial. This paper sets out a review of the literature to date, considering that lithium still represents the gold standard among prophylactic treatments of manic-depression several decades after its introduction. METHOD: PubMed database was used to search for English-language articles relating to lithium treatment and thyroid function. As the amount of relevant papers totalled several hundreds, this review refers to previous reviews, especially with regard to older literature. Moreover, the authors particularly refer to a series of studies of thyroid function performed in a cohort of patients at different stages of lithium treatment, who were followed up by their group from 1989 onwards. RESULTS: The main findings from this review included: a) lithium definitely affects thyroid function as repeatedly shown by studies on cell cultures, experimental animals, volunteers, and patients; b) inhibition of thyroid hormone release is the critical mechanism in the development of hypothyroidism, goitre, and, perhaps, changes in the texture of the gland which are detected by ultrasonic scanning; c) compensatory mechanisms operate and prevent the development of hypothyroidism in the majority of patients; d) when additional risk factors are present, either environmental (such as iodine deficiency) or intrinsic (immunogenetic background), compensatory potential may be reduced and clinically relevant consequences may derive; e) hypothyroidism may develop in particular during the first years of lithium treatment, in middle-aged women, and in the presence of thyroid autoimmunity; f) thyroid autoimmunity is found in excess among patients suffering from affective disorders, irrespective of lithium exposure; g) in patients who have been on lithium for several years, the outcome of hypothyroidism, goitre, and thyroid autoimmunity do not much differ from those observed in the general population; h) hyperthyroidism and thyroid cancer are observed rarely during lithium treatment. RECOMMENDATIONS: Thyroid function tests (TSH, free thyroid hormones, specific antibodies, and ultrasonic scanning) should be performed prior to starting lithium prophylaxis. A similar panel should be repeated at one year. Thereafter, annual measurements of TSH may be sufficient to prevent overt hypothyroidism. In the presence of raised TSH or thyroid autoimmunity, shorter intervals between assessments are advisable (4-6 months). Measurement of antibodies and ultrasonic scanning may be repeated at 2-to-3-year intervals. The patient must be referred to the endocrinologist if TSH concentrations are repeatedly abnormal, and/or goitre or nodules are detected. Thyroid function abnormalities should not constitute an outright contraindication to lithium treatment, and lithium should not be stopped if a patient develops thyroid abnormalities. Decisions should be made taking into account the evidence that lithium treatment is perhaps the only efficient means of reducing the excessive mortality which is otherwise associated with affective disorders.

Journal Article↗

Lithium regulates protein tyrosine phosphatase activity in vitro and in vivo.

RATIONALE: Lithium has been shown to regulate multiple intracellular signaling pathways by affecting various protein kinases. However, the counterpart of protein kinases, i.e., protein phosphatases may play an important role in lithium-regulated cellular signaling and functions. OBJECTIVES: The present work was designed to test the effect of lithium on protein phosphatases in vitro and in vivo. METHODS: PC12 cells were used as an in vitro model to characterize the effect of lithium on protein phosphatase activity. Rats treated with a lithium-containing diet were used to examine the in vivo effect of the drug on brain protein phosphatase activity.RESULTS. Lithium stimulated protein tyrosine phosphatase (PTPase) activity in a dose- and time-dependent manner in PC12 cells. A maximal stimulation of 87% was observed after 6 h of incubation with 3 mM LiCl. In contrast, protein serine phosphatase (PSPase) activity was not changed by lithium. The stimulatory effect on PTPase was not due to a direct action of the ion on the enzymes, but its selectivity was noted since treatment of cells with other monovalent cations exhibited no effect on PTPase activity. Lithium appeared to target specific PTPase(s) as it stimulated membrane-associated PTPase activity without affecting cytosolic or nuclear enzymatic activities. Moreover, the stimulation of PTPase activity in PC12 cells by lithium is independent of de novo protein synthesis. In the rat, 3 weeks of lithium treatment significantly elevated PTPase activity in hippocampus, striatum and cortex. CONCLUSION: The present findings provide the first evidence that lithium treatment selectively increases membrane-associated PTPase activity and suggest that this action may contribute to the pharmacotherapeutic actions of lithium.

Animals↗