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)

The amyloid beta protein is deposited in the brains of patients with Alzheimer's disease but its pathogenic role is unknown. In culture, the amyloid beta protein was neurotrophic to undifferentiated hippocampal neurons at low concentrations and neurotoxic to mature neurons at higher concentrations. In differentiated neurons, amyloid beta protein caused dendritic and axonal retraction followed by neuronal death. A portion of the amyloid beta protein (amino acids 25 to 35) mediated both the trophic and toxic effects and was homologous to the tachykinin neuropeptide family. The effects of the amyloid beta protein were mimicked by tachykinin antagonists and completely reversed by specific tachykinin agonists. Thus, the amyloid beta protein could function as a neurotrophic factor for differentiating neurons, but at high concentrations in mature neurons, as in Alzheimer's disease, could cause neuronal degeneration.
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PMID:Neurotrophic and neurotoxic effects of amyloid beta protein: reversal by tachykinin neuropeptides. 221 31

Degeneration of cholinergic neurons from the basal forebrain nuclei is suspected to be the cause of Alzheimer disease. We have developed dissociated cultures of cholinergic neurons from these nuclei (the nucleus basalis of Meynert, the medial septal nucleus, and the diagonal band nuclei). Brain slices of the forebrains were made by a vibratome, and the basal forebrain nuclei were dissected out, dissociated, and cultured. Choline acetyltransferase immunocytochemistry and acetylcholinesterase cytochemistry revealed large cholinergic cells (average diameter, 20-25 micron) in these cultures. About 75% of large neurons (20 micron or larger in diameter) were cholinergic. Electrophysiological experiments were performed on these large neurons. The neurons usually did not show spontaneous firing, but steady depolarizations produced trains of action potentials, which adapted quickly. The neurons responded with depolarization to the application of L-glutamic acid. Substance P produced depolarization (sometimes hyperpolarization), and during the depolarization membrane resistance was increased.
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PMID:Dissociated cell culture of cholinergic neurons from nucleus basalis of Meynert and other basal forebrain nuclei. 241 32

In the present immunocytochemical study we examined brain tissue of patients with Alzheimer's disease in order to determine the relationship of substance P (SP)-labeled processes to neuritic plaques. Swollen neuropeptidergic processes were consistently observed within a relatively small percentage of the plaques. These data provide a morphologic correlate to the biochemical finding that SP levels are reduced in the brain tissue of patients with Alzheimer's disease, and further indicate that Alzheimer's disease affects multiple neurotransmitter and neuropeptide systems.
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PMID:Substance P immunoreactivity within neuritic plaques. 241 95

Substance P is an undecapeptide which has been found in human cortical neurons. We measured concentrations of this peptide in Alzheimer's disease (AD) and control postmortem tissue by radioimmunoassay. Using high-performance liquid chromatography, most of the immunoreactivity from AD or control temporal cortex comigrated with synthetic standards. Significant reductions of 20 to 40% in substance P-like immunoreactivity were found in AD cerebral cortex and hippocampus, most severe in the inferior temporal gyrus. Substance P neurons or their terminals are vulnerable to the pathophysiologic process in AD.
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PMID:Substance P-like immunoreactivity is reduced in Alzheimer's disease cerebral cortex. 243 49

Polyclonal antibodies directed against substance P, somatostatin, neurotensin, cholecystokinin (CCK), leucine enkephalin, and vasoactive intestinal polypeptide (VIP) were employed to determine the immunoreactivities of neurites of senile plaques (SP) in Alzheimer's disease (AD). All of the antibodies labeled some neurites in some SP. The transmitter specificities of immunoreactive neurites tended to reflect the distribution of transmitter-associated fibers in normal tissue. This investigation also documented the presence of abnormal axons (as distinct from neurites within plaques) in the neuropil in brains of individuals with AD and in some aged controls. These findings suggest that a variety of transmitter systems are involved in the formation of neuropil abnormalities of SP. They also indicate that a greater number of neuronal systems are affected in AD than have been documented by neurochemical studies.
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PMID:Neuropeptidergic systems in plaques of Alzheimer's disease. 244 13

A large number of neuropeptides have been found in cortical neurons. They are therefore of interest in attempting to demonstrate selective vulnerability of different populations of neurons in Alzheimer's disease (AD). The most consistent neuropeptide deficit in AD is reductions in cortical concentrations of somatostatin. Lesser reductions in corticotropin-releasing factor, neuropeptide Y and substance P have been reported. Concentrations of both vasoactive intestinal polypeptide and cholecystokinin are relatively preserve. The morphologic correlate of reduced somatostatin concentrations in AD appears to be markedly distorted and reduced terminal fiber plexuses, rather than reduced numbers of neuronal perikarya. A large number of neuropeptides have been localized in senile plaques.
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PMID:Neuropeptides in Alzheimer's disease. 244 13

Alzheimer's disease (AD) is one of more than 60 disorders that may produce dementia. It is characterized clinically by memory deficits and by the presence of aphaso-apracto-agnosic disorders. In the general population, AD has an incidence of 0.3 to 1% and is very common in the elderly (more than 50% of dementia cases). The pattern of pathological changes in the brain in AD is relatively specific. Neuritic plaques, neurofibrillary tangles and cell loss, occur primarily in the cerebral neocortex and hippocampus. On the other hand, neurochemical deficiencies related to the illness have now been identified. The vulnerability of the cholinergic system of the basal nucleus of Meynert was first documented. Following the discovery of the cholinergic reduction in AD and among a dozen of neurotransmitter systems involved in AD, somatostatin, substance P, neuropeptide Y, corticotropin releasing factor and amino acid glutamate were investigated and are the most affected in AD. Results of previous publications and our own investigations are presented here.
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PMID:[Neuromodulators and Alzheimer's disease]. 246

Substance P is found in both the basal ganglia and cerebral cortex in mammalian brain. In the present study postmortem concentrations of substance P-like immunoreactivity (SP-LI) were measured in the globus pallidus, substantia nigra and 22 cortical regions in a group of demented patients with neuropathological features of both Parkinson's disease (PD) and Alzheimer's disease (AD), and from neurologically normal controls. There were no significant changes in the globus pallidus but concentrations were significantly reduced by 44% in the substantia nigra compacta in the PD patients. In cerebral cortex small (20-30%) significant reductions of SP-LI were found in the PD patients in 7 of 22 cortical regions examined. These results are similar to changes found in AD alone and provide further evidence that the dementia of PD is frequently related to the coincidence of PD and AD.
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PMID:Substance P-like immunoreactivity in brains with pathological features of Parkinson's and Alzheimer's diseases. 247 78

In recent years the present authors and others have sought to determine the neurochemical composition of the dilated neuronal processes found within neuritic plaques of patients with Alzheimer's disease. To date a number of neurotransmitter and neuropeptide systems have been observed within different plaques, yet at present it is unclear whether individual human plaques contain more than one transmitter substance. In the present study a highly sensitive dual-immunolabeling procedure was employed and it was demonstrated that substance P and somatostatin-immunoreactive profiles coexist within single senile plaques of patients with Alzheimer's disease. Coexistence of somatostatin and substance P immunoreactivity within plaques was observed in the hippocampus and amygdala but not in the neocortex, although the latter region contained plaques within which somatostatin and substance P existed alone. The frequency with which we observed one or more neuropeptide within plaques was relatively low and in fact most plaques contained neither substance P nor somatostatin immunoreactivity. In addition, a large number of swollen peptidergic processes were observed outside of plaques. The significance of these observations with respect to the pathogenesis of Alzheimer's disease is discussed.
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PMID:Substance P and somatostatin coexist within neuritic plaques: implications for the pathogenesis of Alzheimer's disease. 248 May 52

The relationship between peptidergic dystrophic neurites and paired helical filament (PHF)-positive neurites in Alzheimer's disease (AD) senile plaques (SPs) was studied using combined fluorescence and bright-field optics. Cryostat sections of AD hippocampi were first stained with thioflavine-S and immunolabelled with antisera raised against different neuropeptides: somatostatin-28(1-12), somatostatin-14, neuropeptide Y, cholecystokinin (CCK) and substance P. Secondly, using the elution-restaining procedure, sections were immunolabelled with anti-tau/PHF. In immature SPs, clusters of abnormal, swollen neurites were found. The dystrophic, strongly peptidic-positive neurites contained fewer PHFs than the poorly positive ones. Cell bodies, exhibiting a peptidic content, could be found within SPs without any alteration. These results suggest the following sequence of events: an extracellular poisoning mechanism, perhaps the amyloid substance, first changes the structure of presynaptic endings and causes the formation of ballooning dystrophic neurites filled with their normal peptidic content. Subsequently, intracellular degradation occurs with formation of the PHFs. Then the other structures such as dendrites and perikarya are damaged by the same mechanism. Therefore, this phenomenon seems to precede any formation of PHFs in SPs.
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PMID:Dystrophic peptidergic neurites in senile plaques of Alzheimer's disease hippocampus precede formation of paired helical filaments. 249 27


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