UMLS:C0011570 - FACTA Search

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)

Substance P (SP) is a neuropeptide with a known involvement in anxiety and nociception processes, which acts through the activation of neurokinin-1 (NK(1)) receptors. Recently, a NK(1) receptor antagonist has been shown to display antidepressant activity comparable to that of the selective serotonin reuptake inhibitor paroxetine, but with a better side effect profile. Given their lack of affinity for monoamine transmitters, the antidepressant role of NK(1) receptor antagonists has been attributed to a unique mechanism. However, monoaminergic neurons receive an important SP innervation and also posses NK(1) receptors (noradrenergic neurons of the locus coeruleus) or are in close apposition to NK(1)-containing cells (serotonergic neurons of the dorsal raphe nucleus). In addition, NK(1) receptors are expressed in brain regions involved in the regulation of affective behaviours and the neurochemical response to stress. For these reasons, it has also been postulated that the purported antidepressant action of NK(1) receptor antagonists may result from the modulation of such brain monoaminergic systems. Indeed, systemic administration of NK(1) receptor antagonists enhances the firing rate of dopaminergic, noradrenergic and serotonergic neurons. This effect on serotonergic cells is seen consistently only after long-term treatment and has been associated with a functional desensitisation of somatodendritic 5-HT(1A) autoreceptors. Mice lacking NK(1) receptors also show an increased basal firing rate of 5-HT cells in vivo. These observations are suggestive of a predominating inhibitory role of SP upon monoaminergic neurons under physiological conditions and would provide support for the antidepressant activity of NK(1) receptor antagonists, although this may be achieved through an indirect action on other transmitter systems. The possibility that this class of drugs can modulate the function of only certain serotonergic pathways could be the basis of their better side effect profile. However, although preliminary studies showed some therapeutic efficacy for NK(1) receptor antagonists, the first compound developed (MK-869) has been discontinued from Phase III trials because it was not more effective than placebo in the treatment of depression. Further research is needed to ascertain whether the mechanism of action of NK(1) receptor antagonists may be relevant to the antidepressant treatment.
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PMID:Antidepressant properties of substance P antagonists: relationship to monoaminergic mechanisms? 1507 86

The neuropeptide substance P evokes a long-term protein synthesis-dependent increase in the cycle frequency of locomotor network activity in the lamprey. Although cellular and synaptic mechanisms that could induce this effect have been identified, nothing is known of the underlying maintenance mechanisms. These mechanisms have been examined here. Substance P potentiates low-frequency-evoked EPSPs from excitatory network interneurons. It also converts the depression of the EPSP during spike trains into facilitation, an example of metaplasticity. The metaplasticity was associated with a reduction of the transmitter release probability but an increase in the number of release sites. Although the potentiation of low-frequency-evoked EPSPs recovered within 1 hr, the metaplastic facilitation had not recovered 3-4 hr after substance P application. The metaplasticity thus extended into the protein synthesis-dependent maintenance phase of the network modulation, making it the only identified cellular or synaptic effect of substance P to last this long. It also had the same induction and maintenance features as the network burst frequency modulation, further suggesting that the two effects were related. Long-term changes in synaptic properties are often associated with changes in synaptic organization. We have thus also examined the effects of substance P on synaptic ultrastructure up to 5 hr after substance P application. Substance P had several significant effects. These included an increase in the number of docked vesicles and a reduction of the synaptic gap. Substance P thus has long-term effects on synaptic organization and function. The relevance of these effects to the long-term locomotor network modulation is discussed.
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PMID:Metaplastic facilitation and ultrastructural changes in synaptic properties are associated with long-term modulation of the lamprey locomotor network. 1549 82

Research on Substance P (SP) has, until recently, focused on its role in pain and inflammation. However, a report that NK(1) receptor antagonists have utility in the treatment of depression has stimulated research into the function of SP and the NK(1)receptor in anxiety and depression. The distribution of SP and the NK(1) receptor in brain areas implicated in anxiety and depression is initially reviewed. This is followed by evaluation of the preclinical data obtained for SP and NK(1) receptor antagonists in behavioral models of depression as well as the phenotype of genetically modified animals lacking the genes encoding for the NK(1) receptor or for SP. The weight of the evidence supports antidepressant and anxiolytic activity of NK(1) receptor antagonists. However, many of the studies do not control for nonspecific effects of the compounds, and when enantiomers that lack activity at the NK(1) receptor are included, the results, in some cases, suggest that blockade of NK(1) receptors does not account for the observed behavioral activity. Finally, clinical studies in depressed patients assessing SP levels in plasma and cerebrospinal fluid as well as the effect of NK(1) receptor antagonists are reviewed. The clinical studies are a mixture of positive, failed and negative studies on the antidepressant activity of NK(1) receptor antagonists, not unlike the early clinical results obtained with selective serotonin reuptake inhibitors.
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PMID:Do substance P and the NK1 receptor have a role in depression and anxiety? 1589 60

Substance P (SP)/Neurokinin 1 (NK1) receptor pathways have been repeatedly implicated in the pathophysiology of central, pulmonary, and gastric disorders. A large body of evidence that has been generated from animal experiments indicates that treatment with selective NK1 receptor antagonists might be effective in the treatment of certain forms of disorders, analgesia, depression, migraine, asthma, or gastrointestinal disorders. Accordingly, numerous NK1 receptor antagonists have either been synthesized and are under clinical development, or have already been tested in clinical trials. However, the initial encouraging clinical results were followed by repeated demonstration of a lack of effectiveness. Up to now, only one NK1 receptor antagonist, aprepitant, is available for therapeutical use. Aprepitant is a selective high-affinity human SP/NK1 receptor antagonist approved by the FDA in 2003. Aprepitant is indicated for prophylaxis of acute- and delayed-phase nausea and emesis caused by chemotherapy regimens. It is used in combination with a 5-hydroxytryptamine (5-HT3) antagonist and a corticosteroid. It is the first antiemetic agent that acts by binding the NK1 receptor. Research continues and novel molecules may show better pharmacokinetic and pharmacodynamic properties and, therefore, may achieve therapeutic success.
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PMID:[Neurokinin 1 receptor antagonists--between hope and disappointment]. 1679 96

Substance P (SP) has been associated with pain and depression as well as neurodegenerative diseases. Many of these diverse actions of SP can potentially be attributed to SP metabolites generated at the blood-brain barrier (BBB). In this study, the metabolism of SP was investigated using an in vitro model of the BBB and LC-MS/MS. Substance P metabolism was found to be non-saturable in the concentration range of 100 nM to 10 microM, with approximately 70% of the peptide remaining intact after 5 h. The major metabolites of SP were identified by MS as 3-11 and 5-11. Two previously unreported metabolites, 5-11 and 6-11, were also found in our studies. Several additional minor SP metabolites, including 1-9 and 2-11, were also identified. A profile of the SP metabolites generated by the BBB over time was obtained. The results from the present study provide a better understanding of the role of the blood-brain barrier in the pharmacology of SP.
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PMID:Investigation of the metabolism of substance P at the blood-brain barrier using LC-MS/MS. 1711 6

Substance P is involved in the modulation of depression, anxiety, and suicidal-related behaviors. We studied gene variants of Tachykinin Receptor 1 (TACR1-rs3771810, rs3771825, rs726506, rs1477157) in 167 German suicide attempters (affective spectrum n = 107, schizophrenia spectrum n = 35, borderline personality disorder n = 25), 92 Caucasian individuals who committed suicide and 312 German healthy subjects. Single markers and haplotype analysis in relation to suicidal behaviors (suicide attempters/completers) did not reveal any significant association. The rarest rs3771825 T allele however showed a marginal association with higher Reactive Aggression scores on the Questionnaire for Measuring Factors of Aggression (FAF) (F = 9.86, df = 1; P = 0.0017). Haplotype analyses confirmed the finding. Violence or impulsivity of suicide attempt and State-Trait Anger Expression Inventory (STAXI) scores were not associated with gene variants. In conclusion, our study suggests that TACR1 gene variants have no major influence on suicidal behavior but may modulate aggression features.
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PMID:Tachykinin receptor 1 variants associated with aggression in suicidal behavior. 1744 17

Substance P (SP) is possibly involved in the pathophysiology of depression and anxiety. We investigated interactions between antidepressants on SP-induced effects and their potential calcium-blocking activity in the isolated guinea pig ileum. All the antidepressants tested, except pargyline, moclobemide, mianserin, and reboxetine, were able to inhibit in a concentration-dependent manner the contraction induced by 100 nmol/L SP. Clomipramine, fluoxetine, maprotiline, and amitriptyline (all at 3 mumol/L) flattened the concentration-response curves to SP, resulting in a reduction of up to 59%, 63%, 32%, and 23%, respectively, of the maximum contractile effect. All the antidepressants tested (3 mumol/L), except pargyline, moclobemide, and mianserin, produced a rightward parallel shift of the concentration-response curve to CaCl2. The L-type selective calcium blocker nifedipine and the T-type selective mibefradil showed similar behaviour against both agonists used, SP and CaCl2. The relative order of potency was nifedipine (pA2, 7.6 +/- 0.1) > clomipramine (pA2, 7.0 +/- 0.1) > fluoxetine (pKB, 6.5 +/- 0.1) = mibefradil (pKB, 6.6 +/- 0.1) > amitriptyline (pKB, 6.3 +/- 0.1) = maprotiline (pKB, 6.2 +/- 0.1) > fluvoxamine (pKB, 5.9 +/- 0.1). The data reported in the present study suggest that the antidepressants tested did not behave as competitive antagonists versus NK1-receptor subtypes, but their inhibitory action seems to be related to their calcium-blocking properties.
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PMID:Older versus newer antidepressants: substance P or calcium antagonism? 1806 1

Glutamate exerts its effects through binding and activation of two classes of specific receptors: ionotropic (iGluRs) and metabotropic (mGluRs). Group I mGluR includes mGluR1 and mGluR5 subtypes, group II includes mGluR2 and mGluR3 subtypes and group III includes the subtypes mGluR 4, 6, 7 and 8. Glutamate and its receptors are found in all key hypothalamic areas critically involved in reproduction and neuroendocrine function. To date, considerable data support an important role for iGluRs in the control of neuroendocrine function; however, the role of mGluRs as regulators of hypothalamic-pituitary function has not been clearly elucidated. mGluRs could be exerting a fine tune on the release of hypothalamic factors that regulate hormone release such as Substance P, GABA, alpha-MSH and CRH. Group II mGluR exert a direct inhibitory effect on anterior pituitary prolactin and GH secretion. Moreover, some group II mGluR agonists, like LY 354,740 and LY 379,268, can modulate PRL secretion from the anterior pituitary through their actions as dopamine receptor agonists. Evidence suggests a role for group III mGluR subtypes in stress-related behavioral disorders. Several reports indicate that selective ligands for mGluR subtypes have potential for the treatment of a wide variety of neurological and psychiatric disorders, including depression, anxiety disorders, schizophrenia, epilepsy and Alzheimer's disease among others. Since converging lines of evidence suggest a role for mGluRs subtypes in neuroendocrine regulation of hormone secretion, mGluRs neuroendocrine actions must be taken in consideration to insure proper treatment of these diseases. Moreover, discovery of selective agonists provides an opportunity to investigate the physiological role of mGluR subtypes and to directly test the neuroendocrine actions of mGluRs. Finally, mGluRs selective agonists may have an impact in the treatment of conditions involving chronic stress, such as depression and anxiety disorders, since they regulate neuroendocrine stress circuits involving the HPA axis and stress-sensitive hormones such as oxytocin and prolactin. This review aims to provide a survey of our current understanding of the effects of mGluR activation on neuroendocrine function.
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PMID:Role of metabotropic glutamate receptors in the control of neuroendocrine function. 1861 55

This study characterized the novel neurokinin (NK)(1) antagonist, vestipitant, under clinical evaluation for treatment of anxiety and depression. Vestipitant possessed high affinity for human NK(1) receptors (pK(i), 9.4), and potently blocked Substance P-mediated phosphorylation of Extracellular-Regulated-Kinase. In vivo, it occupied central NK(1) receptors in gerbils (Inhibitory Dose(50), 0.11 mg/kg). At similar doses, it abrogated nociception elicited by formalin in gerbils, and blocked foot-tapping and locomotion elicited by the NK(1) agonist, GR73632, in gerbils and guinea pigs, respectively. Further, vestipitant attenuated fear-induced foot-tapping in gerbils, separation-induced distress-vocalizations in guinea pigs, marble-burying behaviour in mice, and displayed anxiolytic actions in Vogel conflict and fear-induced ultrasonic vocalization procedures in rats. These actions were mimicked by CP99,994, L733,060 and GR205,171 which acted stereoselectively vs its less active isomer, GR226,206. In conclusion, vestipitant is a potent NK(1) receptor antagonist: its actions support the utility of NK(1) receptor blockade in the alleviation of anxiety and, possibly, depression.
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PMID:Cellular and behavioural profile of the novel, selective neurokinin1 receptor antagonist, vestipitant: a comparison to other agents. 1865 1

Substance P (SP) has been reported to produce effects on excitatory synaptic transmission in the nucleus accumbens (NAc) that are similar to those induced by cocaine. To address the question of whether SP serves as an endogenous mediator producing cocaine-like effects that are known to be D1-receptor-mediated, we tested the hypothesis that the effects of SP and cocaine on excitatory postsynaptic currents (EPSCs) in the NAc occlude one another. We report here that SP and SP(5-11) actions occlude the effect of cocaine and vice versa. SP, SP(5-11) and cocaine all depressed evoked, non-N-methyl-D-aspartate (NMDA) receptor-mediated synaptic currents in a concentration-dependent manner, with EC50 values of 0.12, 0.17 and 8.3 microm, respectively. Although cocaine was the least potent, it was most efficacious. SP, SP(5-11) and cocaine all suppressed isolated NMDA receptor-mediated evoked EPSCs. SP(5-11) (1 microm)-induced EPSC depression was blocked by the neurokinin-1 antagonist L732138 and by the D1-like receptor antagonist SCH23390. Pretreatment of slices with cocaine (30 microm) depressed the EPSC by 39.1% +/- 4.8%. Application of SP or SP(5-11) (1 microm) at the peak of the cocaine depressive effect on the EPSC did not produce any additional diminution of the response (5.7% +/- 2.8%). In the reverse experiments, in which either SP or SP(5-11) was applied first, subsequent application of cocaine at the peak of the peptide's effect (30.3% +/- 2.3%) produced a further but smaller depression (15.5% +/- 3.6%) of the remaining EPSC. These data indicate that cocaine and SP produce similar effects on excitatory synaptic transmission in the NAc, and that their actions occlude one another. This suggests that SP may act like cocaine in its absence, and may be an endogenous trigger for the reward and behaviors associated with cocaine.
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PMID:Substance P and cocaine employ convergent mechanisms to depress excitatory synaptic transmission in the rat nucleus accumbens in vitro. 1938 93

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