Biomedical subjects

Gabriel Nowak

Publications and source records attributed to Gabriel Nowak.

31 records · Page 2Linked to original sources

PubMedDate not supplied

Reduced potency of zinc to interact with NMDA receptors in hippocampal tissue of suicide victims.

Zinc is involved in both psychopathology and treatment of depression. Since a considerable percentage of suicide victims had suffered from depression, we hypothesized that alteration in zinc homeostasis might occur in their brain tissue. We now report that zinc content is not altered in the hippocampal or cortical tissue of suicide victims (n = 10) compared to age-matched controls (n = 10). However, there is a statistically significant 26% decrease in the potency (increase in the IC(50) value) of zinc to inhibit [(3)H]MK-801 binding to NMDA receptors in the hippocampal but not cortical tissue of suicide subjects. The data represent the first demonstration that the alteration in zinc interaction with NMDA receptors may be involved in psychopathology underlying suicidal attempts.

Binding Sites↗

PubMedDate not supplied

Effect of zinc supplementation on antidepressant therapy in unipolar depression: a preliminary placebo-controlled study.

A growing body of evidence implicates a derangement of zinc homeostasis in mood disorders. In general, unipolar depression is connected with low blood zinc levels that are increased by effective antidepressant therapy. A placebo-controlled, double blind pilot study of zinc supplementation in antidepressant therapy was conducted in patients who fulfilled DSM IV criteria for major (unipolar) depression. Patients received zinc supplementation (6 patients; 25 mg of Zn2+ once daily) or placebo (8 patients) and were treated with standard antidepressant therapy (tricyclic antidepressants, selective serotonin reuptake inhibitors). Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI) were used to assess efficacy of antidepressant therapy, and patients' status was evaluated before the treatment and 2, 6 and 12 weeks after its commencement. Antidepressant treatment significantly reduced HDRS scores by the 2nd week of treatment in both groups, and lowered BDI scores at the 6th week in zinc-treated group. Zinc supplementation significantly reduced scores in both measures after 6- and 12-week supplementation when compared with placebo treatment. This preliminary study is the first demonstration of the benefit of zinc supplementation in antidepressant therapy. The mechanism(s) may be related to modulation of glutamatergic or immune systems by zinc ion.

Adult↗

PubMedDate not supplied

Effect of chronic treatment with dexamethasone on brain dopamine receptors in mice.

Glucocorticoids are expressed in the central nervous system. Radioligand binding studies have shown their presence in the neurons of the limbic system, a structure involved in mood control and subtle regulation of hypothalamic-pituitary-adrenal (HPA) axis. Structures of the limbic system are also rich in dopaminergic innervation. It has been hypothesized that glucocorticoids may be important in causing and perpetuating depression. Our previous study has demonstrated that dexamethasone decreases the locomotor activity of mice and counteracts the hyperactivity induced by agonists of dopamine receptors. The aim of the present study was to find the possible mechanism responsible for these behavioral effects of dexamethasone. So we sought to examine the influence of chronic dexamethasone treatment on selective radioligand binding to dopamine D(1) ([(3)H]SCH 23390) and D(2) ([(3)H]spiperone) receptors in the brain of mice. The male Albino Swiss mice received dexamethasone (4, 8 or 16 mg/kg/day) for 14 days. The striatum and limbic system structures were isolated and the binding procedure was performed 3.5 or 48 h after the last injection. It was shown that 3.5 h after the last dose of dexamethasone (4 mg/kg/day), specific D(2) receptor binding was statistically significantly increased (by 64%) in the limbic system. On the contrary, the tendency to the reduction of specific D(2) receptor binding was observed in the striatum. Dexamethasone treatment did not influence the specific binding to D(1) receptors in any structure of the brain.

Animals↗

PubMedDate not supplied

Pharmacokinetic interaction after joint administration of zinc and imipramine in forced swim test in mice.

Recent preclinical and clinical data indicate beneficial role of zinc in the antidepressant treatment. To evaluate the mechanism of interaction between zinc and antidepressants, in the present study we examined the brain zinc, imipramine and desipramine concentrations in mice treated with combinations of zinc and imipramine and subjected to the forced swim test. We have chosen doses of zinc (10 mg/kg) and imipramine (15 mg/kg) which we have previously found to be ineffective in the forced swim test when given alone. However, when administered jointly, a significant reduction in the immobility time in this test was demonstrated. In the present study, we demonstrated a significant ca. 60% reduction in the brain desipramine and non-significant reduction (ca. 40%) in brain imipramine concentrations in the group of animals treated with zinc plus imipramine compared with animals treated with imipramine alone. The brain zinc concentration in the zinc plus imipramine group was reduced when compared with the group treated with zinc or imipramine alone. Since there was no increase in brain imipramine/desipramine or zinc brain concentration after combined zinc and imipramine treatment, the data suggest that pharmacodynamic rather than pharmacokinetic interaction between zinc and imipramine is responsible for behavioral effect in the forced swim test.

Animals↗

PubMedDate not supplied

Effect of imipramine treatment on plasma dopamine beta-hydroxylase activity in chronic mild stress in rats.

Dopamine beta-hydroxylase (DBH) which catalyzes conversion of dopamine into noradrenaline, may be a good blood marker of unipolar depression. Therefore, we studied the effect of classic antidepressant drug imipramine (10 mg/kg ip) on activity of this enzyme in plasma of rats subjected to chronic mild stress (CMS), the model of anhedonia. CMS induced reductions in DBH activity by the second day and 5th week of stress duration. Imipramine treatment minimized these CMS-induced reductions. The data indicate that, similarly to human depression, CMS also affects DBH activity, and, moreover, the CMS-induced alterations are normalized by imipramine treatment.

Animals↗

PubMedDate not supplied

Effects of acute and chronic treatment with magnesium in the forced swim test in rats.

The antidepressant-like activity of magnesium, the non-specific N-methyl-D-aspartate glutamate receptor antagonist, in the mice forced swim test was demonstrated previously. In the present study, the effects of this biometal were studied in the rat forced swim test. Magnesium (MgCl2) at doses ranging from 15 to 50 mg Mg/kg reduced the immobility time in the forced swim test, thus exerting antidepressant-like activity. To evaluate tolerance to this effect, we also performed experiments with the following acute/chronic magnesium treatment schedule: chronic saline and saline challenge at 0.5 h before behavioral experiments (S + S), chronic saline and magnesium challenge (S + Mg), chronic magnesium and saline challenge (Mg + S), chronic magnesium and magnesium challenge (Mg + Mg). The antidepressant-like effect of magnesium was demonstrated in the group treated acutely with magnesium (S + Mg) but not in the chronically treated group (Mg + S) and (Mg + Mg). It is interesting to note that in Mg + Mg group serum concentration of magnesium was quite similar to the S + Mg group (6.44 vs. 6.08 mg/100 ml, respectively), which displayed antidepressant-like effect. The results confirmed that magnesium administered acutely induced the antidepressant-like effects also in rats. However, contrary to mice, chronic treatment with magnesium induced tolerance to this effect in rats.

Animals↗

PubMedDate not supplied

[The role of zinc in the pathogenesis and treatment of affective disorders].

Zinc is an important modulator of glutaminergic transmission. Recent data indicate that pathology of amino-acidergic neurotransmission may contribute to mood disorders and may be involved in antidepressant-like actions in laboratory models. A growing body of evidence implicates a derangement of zinc homeostasis in mood disorders. The zinc deficiency is related to a variety of psychological symptoms especially depression. There are many reports indicating significant changes in blood levels of zinc during a depressive episode. Moreover zinc exhibits antidepressant-like and anxiolytic-like effects in animal models of depression, in rodents. Recent data revealed that zinc enhances the antidepressant effect in laboratory animals. This article reviews the alterations in central and peripheral zinc homeostasis in relation to pathophysiology and treatment of depression.

Adaptation, Psychological↗

PubMedDate not supplied

[The role of copper and magnesium in the pathogenesis and treatment of affective disorders].

Magnesium and copper are important modulators of NMDA-receptor activity. Recent data indicate that disturbances of glutamatergic transmission (especially via NMDA-receptor) are involved in pathogenesis of mood disorders. Magnesium deficiency, the same as disturbances in turn over of copper, are related to a variety of psychological symptoms especially depression. There are many reports indicating significant changes in blood levels of magnesium or copper during a depressive episode. Moreover magnesium exhibits antidepressant-like and anxiolytic-like effects in animal models of depression, in rodents. This article reviews the alterations in central and peripheral magnesium and copper homeostasis in relation to pathophysiology and treatment of depression.

Animals↗

PubMedDate not supplied

Zinc and depression. An update.

Unsatisfactory clinical efficacy and a variety of adverse effects of current antidepressant drugs have incited search for better therapy. Zinc, an antagonist of the glutamate/N-methyl-D-aspartate (NMDA) receptor, exhibits antidepressant-like activity in rodent tests/models of depression. Similarly to antidepressants, zinc induces brain derived neurotrophic factor (BDNF) gene expression and increases level of synaptic pool of zinc in the hippocampus. Clinical observations demonstrated serum hypozincemia in depression, which was normalized by effective antidepressant treatment. Moreover, our preliminary clinical study demonstrated the benefit of zinc supplementation in antidepressant therapy. All the data indicate the important role of zinc homeostasis in psychopathology and therapy of depression and potential clinical antidepressant activity of this ion.

Animals↗

PubMedDate not supplied

Effect of MPEP treatment on brain-derived neurotrophic factor gene expression.

Treatment with most antidepressants induces expression of the gene coding for brain-derived neurotrophic factor (BDNF) in the hippocampus (and cerebral cortex). Recent data indicate antidepressant-like activity of group I mGlu receptor (mGluR1 and mGluR5) antagonists in animal tests/models. We now report that chronic treatment with 2-methyl-6-(phenylethynyl)-pyridine (MPEP), a selective mGlu5 receptor antagonist, increased hippocampal but reduced cortical BDNF mRNA level (Northern blot). Desipramine, a classic antidepressant, increased BDNF mRNA level in both examined brain regions. This is the first demonstration that an antagonist of mGlu5 receptors, like a majority of well-established antidepressants, induces hippocampal BDNF gene expression. A significance of MPEP ability to reduce cortical BDNF needs further study. Nevertheless, this observation further indicates a potential antidepressant activity of the group I mGlu receptor antagonists in human depression.

Animals↗

PubMedDate not supplied

Antepartum/postpartum depressive symptoms and serum zinc and magnesium levels.

In the present study, we investigated the relationship between depressive symptoms and serum zinc and magnesium level in antepartum and postpartum women. All women received standard vitamin, zinc and magnesium supplementation. Sixty-six pregnant women in the Czerwiakowski Hospital in Kraków were assessed for prepartum depressive symptoms using the Beck Depression Inventory (BDI). Sixty-two and fifty-eight women were also assessed for postpartum depressive symptoms (using Edinburgh Postnatal Depression Rating Scale, EPDRS) at 3 and 30 days after delivery, respectively. Serum zinc and magnesium levels were also determined at these time points, however, the number of examined subjects were diminished. A significantly higher EPDRS score (by 45%), indicating severity of depressive symptoms, was found on the 3rd day after childbirth compared with the 30th postpartum day. Moreover, the early post-delivery period (3rd day) was characterized by a 24% lower serum zinc concentration than that found on the 30th day after childbirth. BDI scores assessed a month before childbirth revealed mild depressive symptoms, which was accompanied by a serum zinc concentration similar to that found on the 3rd day after delivery. No significant alterations were found in the magnesium levels between these time points. The present results demonstrated a relationship between severity of depressive symptoms and decreased serum zinc (but not magnesium) concentration in a very specific type of affective disorder, the postpartum depression.

Adult↗

PubMedDate not supplied

Immobility stress induces depression-like behavior in the forced swim test in mice: effect of magnesium and imipramine.

Previously, we demonstrated antidepressant-like effect of magnesium (Mg) in the forced swim test (FST). Moreover, the joint administration of Mg and imipramine (IMI) at ineffective doses per se, resulted in a potent reduction in the immobility time in this test. In the present study, we examined the effect of immobility stress (IS), and Mg and/or IMI administration on FST behavior. IS induced enhancement of immobility time, which was reversed by Mg or IMI at doses ineffective in non-stressed mice (10 mg/kg and 15 mg/kg, respectively). The joint administration of Mg and IMI was effective in both IS and non-stressed animals in FST. IS did not significantly alter locomotor activity, while IMI or Mg + IMI treatment in IS mice reduced this activity. We also measured serum and brain Mg, IMI and its metabolite desipramine (DMI) concentration in mice subjected to FST and injected with Mg + IMI, both restrained and non-restrained. In the present study we demonstrated a significant increase (by 68%) in the brain IMI and a slight, non-significant reduction in DMI concentration in IS + Mg + IMI + FST vs. Mg + IMI + FST groups, which might indicate the reduction in brain IMI metabolism. The IS-induced reduction in brain IMI metabolism did not participate in the activity in FST, since no differences in such activity were noticed between IS + Mg + IMI + FST and Mg + IMI + FST groups. The present data suggest that IS-induced increase in immobility time in FST is more sensitive for detection antidepressant-like activity. However, further studies are needed to examine the effect of other antidepressants in such an experimental paradigm.

Animals↗

PubMedDate not supplied

Medium supplementation with zinc enables detection of imipramine-induced adaptation in glycine/NMDA receptors labeled with [3H]L-689,560.

Antidepressant drugs after chronic administration induce adaptive changes in the NMDA receptor complex. Radioligand-receptorbinding studies using [3H]5,7-dichlorokynurenic acid demonstrated a "down-regulation" of the glycine site/NMDA receptor following chronic treatment with antidepressants and electroconvulsive shock. However, binding procedure using this radioligand is time consuming because it requires the use of centrifugation method in the separation process. The introduction of a new radioligand of glycine/NMDA receptor, [3H]L-689,560 enables the application of a rapid filtration method. In the present study we demonstrate that 2-week treatment with imipramine (15 mg/kg ip) did not evoke alterations in specific [3H]L-689,560 binding and in IC50 value of glycine in displacing [3H]L-689,560 binding in the mouse or rat cortex. However, longer, a 4-week treatment with imipramine induced a significant 71% increase in IC50 value in displacing [3H]L-689.560 binding in the mouse cortex. Moreover, the presence of zinc in the incubation media, dose-dependently enhances detection of imipramine-induced increase in IC50 value of glycine in displacing [3H]L-689,560 binding in the rat cortex. The present data indicate that: (1) [3H]L-689,560 may be a suitable ligand for assessing adaptation of the glycine/NMDA sites and (2) the presence of zinc enhances detection of imipramine-induced reduction of glycine affinity for glycine/NMDA receptors labeled with [3H]L-689,560 which further indicates a significance of zinc in the mechanism of antidepressant treatment.

Adaptation, Physiological↗