Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Kainic acid (KA), a powerful neurotoxic analogue of glutamate, has been extensively used as a tool for selectively lesioning neuronal cell bodies; however, axons or nerve terminals are spared from damage in the area injected with kainic acid. Injections of this neurotoxin in various brain regions were successfully used to locate cell bodies of neurones containing substance P, enkephalin and other putative neurotransmitters. While attempting to locate the cell bodies of the enkephalin containing neurones present in hippocampus using KA injections, we found that a few days after intracerebral injections of KA a drastic increase in the Met-enkephalin (ME) content of hippocampus occurs. We now describe the delayed increase in hippocampal ME content elicited by intracerebral KA injections and examine the possible mechanism that is operative in causing this increase. Moreover, we provide some evidence suggesting that the increase in ME content elicited by intracerebral injections of KA may be related to the recurrent motor seizures elicited by intracerebral injections of KA.
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PMID:Changes of hippocampal Met-enkephalin content after recurrent motor seizures. 737 75

Subcutaneously administered kainic acid (KA) in the rat results in brain damage accompanied by a behavioral response characterized by wet dog shakes (WDS), seizures and brain damage, an effect that is potentiated by opioids. Based on the potentiative effect of the N-terminus of substance P (SP) on the ability of KA to induce behavioral responses in mice, we tested the hypothesis that the N-terminus of SP also plays a role in KA-induced neurotoxicity in rats. Pretreatment i.p. with 1 or 10 nmol of SP(1-7), a major N-terminal metabolite of the undecapeptide SP, 15 min before administration of 12 mg/kg of KA potentiated the incidence of WDS. In contrast, after administration of 1 nmol of [D-Pro2, D-Phe7]SP(1-7) (D-SP(1-7)), the D-isomer of SP(1-7) and a substance P N-terminal antagonist, the intensity of KA-induced WDS was no different from those in either the KA- or saline-injected rats. However, pretreatment with D-SP(1-7) completely blocked the potentiative effect of SP(1-7) on the KA-induced WDS. While the severity of KA-induced lesions was not significantly altered by pretreatment with 1 nmol of SP(1-7), the effect of KA was not significantly different from that in control rats when administered with 1 nmol of D-SP(1-7). These results suggest a possible involvement of endogenous SP N-terminal activity in the effects following subcutaneous (s.c.) administration of KA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Possible role of the N-terminus of substance P in kainic acid-induced toxicity in rats. 750 68

Adult male Wistar rats (n = 21) received bilateral kainic acid lesions of their hippocampi. Over a period of 9 weeks the animals received daily IP injections of either 5 micrograms/kg or 50 micrograms/kg substance P (SP) or vehicle. Seizures provoked by the lesions were suppressed by the daily administration of the neuropeptide SP in a dose of 50 micrograms/kg for the whole period of observation. The neurokinin significantly (p < 0.01) reduced the number of seizures compared to the vehicle-treated animals.
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PMID:Attenuation of hippocampal kainic acid-induced seizures by substance P treatment. 752 47

Marked changes in the expression of the tachykinin peptide neurokinin B (NKB) have been recently observed in animal models of epilepsy. In this study we investigated mRNA levels encoding the receptor for NKB, the neurokinin-3 receptor (NK-3R), after limbic seizures induced by kainic acid (KA) in the rat. NK-3R mRNA levels were determined by nuclease protection assay at various time intervals after i.p. injection of KA in the rat. Increases of more than 200% were observed in NK-3R mRNA in the cerebellum after 7 and 30 days. In the hippocampus a moderate, reversible increase (of 70%, 1 day after KA) was seen. In the frontal cortex a reduction of NK-3R mRNA (2 days after KA) was found. In the amygdala, levels of the transcript were decreased (by 50% and more) at all intervals investigated. The decreases in mRNA levels in the amygdala are consistent with the severe damage observed in this brain area. The increases in NK-3R mRNA in the cerebellum point to the development of receptor supersensitivity and suggest a functional role of NKB in this animal model of epilepsy.
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PMID:Kainic acid induced seizures cause a marked increase in the expression of neurokinin-3 receptor mRNA in the rat cerebellum. 789 59

The expression of neuropeptides and neurotrophic factors is altered in the hippocampus after seizure induction in rats. Because the increase in brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) mRNAs precede changes in neuropeptide expression after seizure, it is possible that BDNF and NGF mediate subsequent alterations in peptide expression. To test this hypothesis directly, BDNF or NGF was infused into the hippocampus and cortex of adult rats. To ascertain the regional specificity of any observed effects of neurotrophin administration on neuropeptide expression, infusions into the striatum were also studied. To control for specificity, vehicle was also infused into the same sites. Peptide and mRNA alterations were assessed by Northern analysis, immunohistochemistry and radioimmunoassay. BDNF produced elevations of peptide and mRNA for neuropeptide Y and cholecystokinin in hippocampus and cortex, and somatostatin in cortex. BDNF increased mRNAs for neuropeptide Y, cholecystokinin, substance P and dynorphin in striatum. In contrast, BDNF decreased dynorphin peptide and mRNA in hippocampus. NGF's effects were limited to small mRNA increases, without corresponding changes in peptide levels, for neuropeptide Y in hippocampus and striatum, substance P in cortex and cholecystokinin in striatum. The distinct and limited effects of NGF infusion on neuropeptide expression demonstrate that BDNF's effects are not non-specific results of protein infusion into the brain. These findings indicate that BDNF may play a regionally specific role in modulating neuropeptide expression in the normal brain as well as in various pathophysiological states.
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PMID:Regulation of neuropeptides in adult rat forebrain by the neurotrophins BDNF and NGF. 798 76

Rats were pretreated with 0.9% NaCl, or 0.1 or 1.0 mg/kg MK-801, an anticonvulsant and a psychotomimetic drug, and 60 minutes later given ECS or sham ECS. After six sessions the animals were sacrificed and neuropeptide Y (NPY-), neurokinin A (NKA-), and calcitonin gene-related peptide (CGRP-) like immunoreactivity (-LI) measured with radioimmunoassays. ECS increased NPY-LI in frontal cortex, striatum, occipital cortex and hippocampus, and NKA-LI in occipital cortex and hippocampus. MK-801 increased CGRP in a dose-response manner in frontal cortex, and NKA-LI in occipital cortex. Although the higher MK-801 dose reduced seizure duration by 50%, the ECS induced NPY-LI increase in striatum, occipital cortex and hippocampus, and NKA-LI in occipital cortex was not diminished. In contrast, there was a parallel decrease in seizures and NPY-LI and NKA-LI changes in frontal cortex and hippocampus, respectively. Investigation of neuropeptides in brain may contribute to understanding of the mechanisms of action of antidepressive and antipsychotic treatments and of psychotomimetic drugs.
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PMID:Effects of electroconvulsive stimuli and MK-801 on neuropeptide Y, neurokinin A, and calcitonin gene-related peptide in rat brain. 913 43

Mice infected with the LP-BM5 murine leukemia virus (MuLV) develop an immune deficiency syndrome together with an encephalopathy characterized by impairments in spatial learning and memory. These cognitive deficits are evident before the appearance of neuron loss and lymphoid cell invasion of the brain. Nonetheless, a prominent gliosis and a variety of neurochemical changes precede the development of cognitive deficits. The neurochemical abnormalities include significant decreases in striatal Met-enkephalin and substance P (but not somatostatin), increases in concentrations of quinolinic acid and platelet-activating factor, and alterations in brain fyn kinase. At this stage of the infection, some of these neurochemical changes can be reversed by glutamate receptor antagonists, cytokine inhibitors, and anti-retroviral agents. In later stages of the infection, however, the infected mice develop irreversible neuronal loss, invasion of hematopoietic cells, and increased viral burden in the CNS. In addition, motor-neuron dysfunction (hindlimb paralysis, weakness, and ataxia) and seizures are sometimes observed during the late stages of infection. Thus, the LP-BM5 MuLV-infected mouse is a useful model for studying the chronology of neurodegenerative changes, ranging from reversible neuron dysfunction to irreversible neuron loss, that are associated with retrovirus-induced immunodeficiency.
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PMID:The encephalopathy associated with murine acquired immunodeficiency syndrome. 962 8

Substance P (SP) can play an important role in neuronal survival. To analyze the role of SP in excitotoxicity, kainic acid (KA) was administered to rats and in situ hybridization was used to analyze the levels of the SP encoding preprotachykinin-A (PPT-A) mRNA in striatal and hippocampal subregions 1, 4, and 24 h and 7 days after KA. In striatum and piriform cortex, PPT-A mRNA peaked 4 h after KA while in hippocampus, levels peaked after 24 h. KA caused seizures and neuronal toxicity as indicated by a reduction of the number of neurons in the hippocampal CA1 subregion after 7 days. KA was later administered alone or following pretreatment with the tachykinin NK1 receptor antagonist CP-122,721-1 (0.3 mg/kg). The pretreatment decreased seizure activity and a negative correlation was found between seizure activity and survival of CA1 neurons. Conclusively, treatment with CP-122,721-1 has a seizure inhibiting property and may possibly counteract KA-induced nerve cell death in CA1.
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PMID:A tachykinin NK1 receptor antagonist, CP-122,721-1, attenuates kainic acid-induced seizure activity. 975 66

Neuropeptides: corticotropin releasing factor (CRF), neuropeptide Y (NPY) and somatostatin (STS) have been associated with depression and anxiety, while neurotensin (NT), calcitonin gene-related peptide (CGRP) and tachykinins [neurokinin A (NKA) and substance P (SP)] are presumed to also play a role in the function of the dopaminergic system. Moreover, investigations in the past decade have shown that psychotomimetics and antipsychotic drugs as well as lithium affect brain synthesis, tissue concentrations, and release of some neuropeptides. In view of the above, experiments were carried out to explore whether changes in neuropeptides constitute one of the mechanisms of action of electroconvulsive treatment (ECT). Human cerebrospinal fluid (CSF) was studied before and after ECT, and brains from healthy and models of depression rats were investigated in electroconvulsive stimuli (ECS)-treated and sham-treated animals. The major findings were that a series of ECTs, in parallel to clinical recovery, increased CSF concentrations of NPY-like immunoreactivity (-LI), STS-LI, and CRF-LI, and in one study endothelin-LI. A series of ECS, but not a single treatment, reproducibly elevated concentrations of NPY-LI, NKA-LI, and STS-LI--but not NT-LI, SP-LI, galanin-LI, or CGRP-LI--in hippocampus, frontal cortex, and occipital cortex. No changes were measured in other regions, e.g., striatum. NPY and STS mRNAs were also increased indicating that ECS affects peptide synthesis. Generalized seizures induced by, e.g., kainic acid or pentylenetetrazole, had similar effects on neuropeptides. The changes persisted for at least 1 week after the last treatment. Pretreatment with compounds reducing seizures, such as benzodiazepines and MK-801; had no effect on magnitude of neuropeptide changes although the seizure duration was decreased by > 50%. On the basis of these findings, it is suggested that neuropeptides are involved in ECT's mechanisms of action. Since ECT is therapeutically efficient in both schizophrenia and depression and, taking into account that antipsychotic drugs and psychotomimetics as well as lithium selectively affect some neuropeptides, it is hypothesized that distinct combinations of neuropeptide and monoamine changes in selected neuronal populations constitute the underpinnings of ECT's effects on specific disease symptoms, conceivably independent of diagnosis.
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PMID:Neuropeptides and electroconvulsive treatment. 1018 19

The purpose of this study was to investigate whether GABA(A) receptors in the dorsal striatum regulate basal or stimulant-induced behaviors. Correspondingly, the question of possible GABA(A) receptor control of neuropeptide mRNA expression in nigrostriatal neurons was addressed. The GABA(A) receptor antagonist, bicuculline, was unilaterally or bilaterally microinjected into the dorsal striatum of rats in a series of 3 studies. In the first study, unilateral administration of 10-50 ng/microliter of bicuculline did not alter behavior. However, 250 ng/microliter bicuculline produced motor dyskinesias and/or seizures. In the second study, 100 ng/microliter bicuculline administered unilaterally prior to saline or amphetamine treatment, produced mild twitching in 61% of rats but did not affect amphetamine (2.5 mg/kg, i.p.)-induced behavioral activity, specifically rearing and sniffing. In the third study, 75 ng/microliter of bicuculline was administered unilaterally or bilaterally into the striatum in two separate experiments. Administration of bicuculline either unilaterally or bilaterally produced mild transient twitching of the forelimbs but did not affect behaviors induced by the selective D(1) receptor agonist SKF-82958 (0.5 mg/kg, s.c.). Three hours after unilateral bicuculline administration, the brains were removed and processed for quantitative in situ hybridization. Bicuculline did not significantly affect the basal or SKF-82958-induced increase in preprodynorphin or substance P mRNA expression in striatonigral neurons on the side of injection. These data suggest that blockade of GABA(A) receptors in the dorsal striatum does not affect dopamine agonist-stimulated behaviors or neuropeptide mRNA expression in striatonigral neurons in the rat striatum.
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PMID:The role of dorsal striatal GABA(A) receptors in dopamine agonist-induced behavior and neuropeptide gene expression. 1041 9


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