Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of ethanol (22 mM) on the modulation of synaptic transmission and long-term potentiation (LTP) by the neurosteroid dehydroepiandrosterone sulfate (DHEAS; 10 microM) was examined in the in vitro rat hippocampal slice preparation. The synaptic responses were elicited by Schaffer collateral stimulation and recorded extracellularly in the somatic and dendritic regions of CA1 pyramidal neurons. LTP induction produced an increase (approximately 55% to 75%) in the amplitude of synaptic responses in ethanol and ethanol plus DHEAS (ethanol/DHEAS) treated slices. These increases were significantly smaller than the approximately 130% increase observed previously in slices treated with DHEAS, but were not significantly different from the approximately 82% increase observed in control slices. These results indicate that an ethanol/DHEAS interaction prevents the enhancement of LTP normally observed with DHEAS treatment of hippocampal slices. An ethanol/DHEAS interaction also altered DHEAS's effects on individual synaptic components of the synaptic response to Schaffer collateral stimulation. Ethanol applied before but not after DHEAS prevented DHEAS's enhancement of the NMDA receptor-mediated synaptic component. DHEAS's depression of the GABAA receptor-mediated synaptic component was also blocked by ethanol. Ethanol or DHEAS individually had no effect on the AMPA receptor-mediated synaptic component, but application of ethanol after DHEAS resulted in a small enhancement of this synaptic component, an effect that was not observed if ethanol was applied before DHEAS. These results show that ethanol and DHEAS interact, altering DHEAS's effects on synaptic transmission and LTP in the hippocampus. Such an interaction may be involved in ethanol's actions on the CNS and raises the possibility that ethanol and DHEAS may act via a common site or pathway.
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PMID:Acute alcohol blocks neurosteroid modulation of synaptic transmission and long-term potentiation in the rat hippocampal slice. 892 87

Standard replacement for adrenal insufficiency (AI) consists of glucocorticoids and mineralocorticoids while DHEA deficiency is routinely ignored. Thus, AI represents the ideal pathophysiological model of isolated DHEA deficiency. We investigated the effects of DHEA replacement in 24 women with primary and secondary AI employing a double blind, placebo-controlled, randomized crossover design. A DHEA dose of 50 mg/d was chosen based on preceding single-dose pharmacokinetics and bioconversion studies. Each patient received four months of treatment with DHEA and four months placebo, with a one-month washout period. Measurements included serum steroid hormones, somatotropic parameters and psychometric assessment of well-being, mood, cognition and sexuality. Treatment with DHEA raised the initially low serum concentrations of DHEA, DHEAS, androstenedione, and testosterone into the normal range. DHEA induced a slight increase in serum IGF-I, but only in patients with primary AI, suggesting a growth hormone-mediated effect. DHEA treatment significantly improved overall wellbeing as well as scores for depression, anxiety, and their physical correlates. Furthermore, DHEA significantly increased both sexual interest and the level of satisfaction with sex. DHEA replacement had no influence on the cognitive performance, which was already on a high level at baseline. In conclusion, DHEA replacement improves well-being and sexuality in women with adrenal insufficiency. If this is due to a direct effect of DHEA on the brain, an indirect effect via increased androgen synthesis, or both, remains to be elucidated. Long-term studies in patients of both sexes are needed to further define the role of DHEA in standard replacement for adrenal insufficiency.
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PMID:DHEA replacement in women with adrenal insufficiency--pharmacokinetics, bioconversion and clinical effects on well-being, sexuality and cognition. 1119 20

Testosterone induces a lethal outcome in otherwise self-healing blood-stage malaria caused by Plasmodium chabaudi. Here, we examine possible testosterone effects on the antimalaria effectors spleen and liver in female C57BL/6 mice. Self-healing malaria activates gating mechanisms in the spleen and liver that lead to a dramatic reduction in trapping activity, as measured by quantifying the uptake of 3-mum-diameter fluorescent polystyrol particles. However, testosterone delays malaria-induced closing of the liver, but not the spleen. Coincidently, testosterone causes an approximately 3- to 28-fold depression of the mRNA levels of nine malaria-responsive genes, out of 299 genes tested, only in the liver and not in the spleen, as shown by cDNA arrays and Northern blotting. Among these are the genes encoding plasminogen activator inhibitor (PAI1) and hydroxysteroid sulfotransferase (STA2). STA2, which detoxifies bile acids, is suppressed 10-fold by malaria and an additional 28-fold by testosterone, suggesting a severe perturbation of bile acid metabolism. PAI1 is protective against malaria, since disruption of the PAI1 gene results in partial loss of the ability to control the course of P. chabaudi infections. Collectively, our data indicate that the liver rather than the spleen is a major target organ for testosterone-mediated suppression of resistance against blood-stage malaria.
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PMID:Testosterone suppresses protective responses of the liver to blood-stage malaria. 1561 82

Depressed patients with resistance to electroconvulsive treatment (ECT) had high basal serum levels of dehydroepiandrosterone (DHEA) sulfate (DHEAS). To clarify the role of DHEA/S in the ECT resistance, Flinder Sensitive Line (FSL) rats, which are a genetic animal model of depression, were injected i.p. with 2 mg/kg DHEA daily for 13 days to overload their serum and brain DHEA/S levels. Thereafter, rats were exposed to electroconvulsive shock (ECS), which is analogue to ECT in humans. Both ECS and DHEA displayed an antidepressive-like effect, as assessed by immobility time in forced swim test. However, combined DHEA and ECS treatment abolished these antidepressive-like effects. In addition, the levels of neurosteroids, corticosterone and adrenocorticotropin in selected brain regions were evaluated and compared to serum levels. The present study supports our assumption that high basal levels of DHEA/S play a role in the resistance to ECS and maybe ECT in humans.
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PMID:The involvement of dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) in blocking the therapeutic effect of electroconvulsive shocks in an animal model of depression. 1582 Apr 13

Dehydroepiandrosterone (DHEA), pregnenolone (P) and their sulfate derivatives are neuroactive neurosteroids synthesized endogenously in the brain and in steroidogenic organs and influence or are influenced by a variety of physiological processes. Since parturition is followed by a rapid drop in estrogen levels in serum and brain it may be hypothesized that the drastic drop in the brain exposure to estrogens may cause a disturbance in the neurosteroid-to-neurosteroid-sulfate equilibrium with clinical relevance. In order to develop a rat animal model for human postpartum rapid estrogen decline conditions, the present study investigated effects of sudden withdrawal of hyperphysiological estrogens levels on levels of DHEA, DHEAS, P and PS in peripheral blood and brain tissue as well as cortical sulfatase activity. Twenty-four 3-month-old female rats were ovarectomized followed by either no estrogen, high levels of estrogen alone, or followed by sudden withdrawal after high-administered estrogen levels. Results indicated elevated brain cortical DHEA-S and reduced cortical sulfatase in ovarectomized rats following sudden estrogen withdrawal. No significant alterations in DHEA, P or PS were noted. Study observations suggest the marked influence estrogen withdrawal states may have on cortical DHEA-S levels in particular, the precise mechanism of which remains unknown but which may be related to the paralleled decrease in sulfatase activity. This DHEA-S increase may lead to attenuated GABAergic tone and may be relevant to post-natal behavioral disturbances (e.g. depression, anxiety).
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PMID:The effect of 17beta estradiol withdrawal on the level of brain and peripheral neurosteroids in ovarectomized rats. 1592 68

The adrenal glands synthesize dehydroepiandrosterone (DHEA) and its sulphate form (DHEAS) more intensively than they do other steroid hormones. Researchers are interested in these hormones for several reasons. Firstly, for some years they have been trying to find the reason for DHEA and DHEAS to be synthesized and present in the organism in such high concentrations. Secondly, their attention have been attracted by age-dependent regression of DHEA, which is strictly determined. Thirdly, despite longstanding efforts of scientists, the physiological role and spectrum of the biological activity of DHEA is still unclear. Evidence of that DHEA and DHEAS can be synthesized in situ in the brain tissue, received in rat experiments, urged researchers to clarify the role of these neurosteroids in the CNS. The presented review covers ways of neurosteroid synthesis, possible mechanisms of the regulation of these processes, and their dynamics under the condition of stress. The authors analyze experimental and clinical observations undertaken with a goal to clarify a possible role of DHEA in the manifestation of various brain functions. Special attention is payed to ambiguous results of modern studies, dedicated to replacement therapy of various disorders of CNS functioning (Alzheimer's disease, depression, age-specific memory impairment, sleep disturbance etc.) with DHEAS.
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PMID:[Dehydroepiandrosterone and brain functioning]. 1614 34

The study was aimed to assess if the prevalence of female depressive disorders after menopause depends on their hormonal status (E2, FSH, testosterone, DHEAS) or psychosocial conditions, Moreover, the influence of HRT on female mood disorders was estimated. One hundred women (44=65 ys old) were included into the study. Ali patients were complaining of hot flushes for at least 6 months. Among these women 31% had depressive disorders at baseline. The hormonal status, psychosocial conditions and mood disorders (Beck's and Haniilton's scales) were assessed at the baseline and after 12 months in 50 women on HRT and in 20 control patients. After 1 year the depressive mood disappeared in 59% and worsened in 5,9% of women taking HRT, whereas in the control group 35% of patient experienced depression. Among women on HRT the significant increase of serum DHEAS was observed in patients with improvement of mood as well as in depressed ones. Serum testosterone, 17P-estradiol and FSH levels did not differ between both groups. The higher scores of Beck's and Hamilton's scales were not associated with hormonal status but correlated with worsening of psychosocial conditions. The female depressive disorders after menopause are associated with their psychosocial conditions but not with their hormonal status.
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PMID:[Are the hormonal status or psychosocial conditions the major cause of female depressive disorders after menopause?]. 1641 94

Hippocampus plays a crucial role in learning and memory and, in spite of its remarkable plasticity, it is also particularly sensitive to stress hormones due to its high concentration of corticosteroid receptors. Indeed, adrenal steroids modulate hippocampal plasticity, acting on excitability and long term potentiation or depression. By a chronobiological approach, we studied the cortisol and DHEAS secretion in clinically healthy old subjects and in age-matched demented patients, including both the degenerative and the vascular type. When compared to young controls, both clinically healthy elderly subjects and demented patients, particularly those with AD, had significantly higher cortisol levels at night time, i.e. at the moment of the maximal sensitivity of HPA axis to stimulatory or inhibitory inputs. At the same time, a clear age- and disease-dependent reduction of DHEAS secretion was found. Thus the cortisol to DHEAS molar ratio was significantly higher in healthy old subjects, and even more in demented patients, when compared to young controls, and significantly linked to both age and cognitive impairment. Finally, the quantitative and qualitative changes of the adrenal secretory pattern were significantly correlated with the decline of hippocampal volumes, measured by MRI. In conclusion, several lines of evidence deal with a pathogenetic role of stress hormones in the occurrence and progression of cognitive disorders in elderly subjects. The consequent hippocampal neuronal impairment may in turn be responsible for the continuous activation of HPA axis and the increased hypothalamic expression of vasopressin and corticotropin releasing hormone.
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PMID:Stress and dementia: the role of the hypothalamicpituitary-adrenal axis. 1670 89

Neurosteroids, pregnenolone (Preg), dehydroepiandrosterone (DHEA) and their sulfates (PregS and DHEAS) are reported to exert their modulatory effects of neuronal excitability and synaptic plasticity via amino acid receptors, which affect and regulate the learning and memory process, mood, and depression. Although the brain levels of these steroids have been reported in rodents, the strain differences of the levels of these steroids have not been demonstrated. We examined the concentrations of Preg, 17-OH-Preg, DHEA, androstenediol (ADIOL) and their sulfates in whole brains from DBA/2, C57BL/6, BALB/c, ddY and ICR mice, the genetic backgrounds of which are different. No differences in the brain levels of Preg and DHEA were found among the strains. In contrast, PregS levels in DBA/2 were significantly lower than in the others, while DHEAS concentrations in DBA/2 were significantly higher than those in other strains. Strain differences were found in 17-OH-Preg, ADIOL and 17-OH-PregS but not in ADIOLS levels. The ranges of Preg and PregS levels were the highest among the steroids studied. Further, we measured serum these steroid levels. Although strain differences were also found in serum steroids, correlation study between brain and serum levels revealed that brain neurosteroids studied may not come from peripheral circulation. In conclusion, this is the first report of demonstrating mammalian brain levels of 17-OH-Preg, ADIOL, 17-OH-PregS and ADIOLS and the strain differences in neurosteroid levels in mice brains. The differences in levels may involve the strain differences in their behavior, e.g. aggression, adaptation to stress or learning, in mice.
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PMID:Strain differences of neurosteroid levels in mouse brain. 1679 26

Of all steroidal hormones, dehydroepiandrosterone (DHEA) and its sulphate form, DHEAS, are synthesized by the adrenal glands in the biggest quantities. In this review the authors consider the ways of the synthesis of the neurosteroids, possible mechanisms of the regulation of these processes, and their dynamics under stressful conditions. The paper presents analysis of experimental and clinical data on the role of DHEAS in the manifestation of different cerebral functions. The authors pay special attention to the results of substitutive therapy with DHEA(S) in patients with such CNS functional disorders, as Alzheimer's disease, depression, age-relative memory and sleep disturbances, etc.
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PMID:[Dehydroepiandrosterone and the cerebral functions]. 1686 61


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