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 central action of peptides to influence GI motility in experimental animals is summarized in Table 1. TRH stimulates gastric, intestinal, and colonic contractility in rats and in several experimental species. A number of peptides including calcitonin, CGRP, neurotensin, NPY, and mu opioid peptides act centrally to induce a fasted MMC pattern of intestinal motility in fed animals while GRF and substance P shorten its duration. The dorsal vagal complex is site of action for TRH-, bombesin-, and somatostatin-induced stimulation of gastric contractility, and for CCK-, oxytocin- and substance P-induced decrease in gastric contractions or intraluminal pressure. The mechanisms through which TRH, bombesin, calcitonin, neurotensin, CCK, and oxytocin alter GI motility are vagally mediated. An involvement of central peptidergic neurons in the regulation of gut motility has recently been demonstrated in Aplysia, indicating that such regulatory mechanisms are important in the phylogenesis. Alterations of the pattern of GI motor activity are associated with functional changes in transit. TRH is so far the only centrally acting peptide stimulating simultaneously gastric, intestinal, and colonic transit in various animals species. Opioid peptides acting on mu receptor subtypes in the brain exert the opposite effect and inhibit concomitantly gastric, intestinal, and colonic transit. Bombesin and CRF were found to act centrally to inhibit gastric and intestinal transit and to stimulate colonic transit in the rat. The antitransit effect of calcitonin and CGRP is limited to the stomach and small intestine. The delay in GI transit is associated with reduced GI contractility for most of the peptides except central bombesin that increases GI motility. Nothing is known about brain sites through which these peptides act to alter gastric emptying and colonic transit. Regarding brain sites influencing intestinal transit, TRH-induced stimulation of intestinal transit in the rat is localized in the lateral and medial hypothalamus and medial septum. The periaqueductal gray matter is a responsive site for mu receptor agonist- and neurotensin-induced inhibition of intestinal transit. The neural pathways from the brain to the gut whereby these peptides express their stimulatory or inhibitory effects on GI transit is vagal dependent with the exception of calcitonin. It is not known whether the vagally mediated inhibition of GI transit by these peptides results from a decrease activity of vagal preganglionic fibers synapsing with excitatory myenteric neurons or an activation of vagal preganglionic neurons synapsing with inhibitory myenteric neurons. The lack of specific antagonists for these peptides has hampered the assessment of their physiological role.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Central nervous system action of peptides to influence gastrointestinal motor function. 210 14

It has been known for some time that NE and ACh can affect voltage-sensitive channels in the heart but it has only recently been appreciated that neurotransmitters (and certain peptides) can modulate voltage-sensitive channels in neurons. In addition to the effect on the action potential of embryonic chick sensory neurons described here, NE decreases the duration of spikes in rat superior cervical ganglion neurons (7). Serotonin prolongs action potentials recorded in Aplysia sensory neurons (9) and an as yet unidentified transmitter decreases an inward Ca++ current in the same cells (20). In the heart, one important consequence of the effect of NE and ACh on the action potential is a change in the strength and/or duration of contraction. In neurons, attention has been focused on the possibility that modulation of voltage-sensitive channels might result in a change in transmitter release. In Aplysia, the 5-HT induced prolongation of sensory neuron some spikes is associated with a dramatic augmentation of transmitter release at sensory nerve-motorneurone synapses (9) and the decrease in some inward Ca++ current is associated with presynaptic inhibition (20). Enkephalin, NE, GABA, and 5-HT can inhibit the evoked release of Substance P from cultured embryonic chick sensory neurons. These same drugs decrease ICa, apparently by decreasing the number of the conductance of voltage-sensitive Ca++ channels. The two phenomena may be related. It is significant in this regard that the same variability (between platings) in the ability of enkephalin to reduce Substance P release was also observed in the effect of enkephalin on action potential duration. Cells that released normal amounts of Substance P in the presence of enkephalin also exhibit spikes of normal duration in the presence of the peptide.
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PMID:Peptide and amine transmitter effect on embryonic chick sensory neurons in vitro. 616 32

The mammalian suprachiasmatic nucleus (SCN) has been identified as a circadian pacemaker. N-methyl-D-aspartate (NMDA), non-NMDA and substance P receptors have been suggested to be involved in handling of photic information in the SCN. In the Aplysia eyes, in which the circadian clocks are involved, serotonin- or cAMP-induced phase changes of the circadian rhythm were reported to be blocked by protein-synthesis inhibitors. Therefore, we investigated whether protein-synthesis inhibitor can block the non- NMDA receptor agonist (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid hydrobromide (AMPA)- or substance P (SP)-induced phase changes of SCN activity rhythm. Although application of 10 microM cycloheximide alone during the early part of the subjective night did not cause phase change, it blocked both 10 microM AMPA- and 1 microM SP-induced phase delay. The present result suggests that protein synthesis may be required in the manifestation of AMPA- and SP-induced phase change of circadian clock.
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PMID:Protein-synthesis inhibitor blocks (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-or substance P-induced phase shift of the circadian rhythm of neuronal activity in the rat suprachiasmatic nucleus in vitro. 751 59

Luqin is a neuropeptide that was discovered and named on account of its expression in left upper quadrant cells of the abdominal ganglion in the mollusc Aplysia californica. Subsequently, luqin-type peptides were identified as cardio-excitatory neuropeptides in other molluscs and a cognate receptor was discovered in the pond snail Lymnaea stagnalis. Phylogenetic analyses have revealed that orthologs of molluscan luqin-type neuropeptides occur in other phyla; these include neuropeptides in ecdysozoans (arthropods, nematodes) that have a C-terminal RYamide motif (RYamides) and neuropeptides in ambulacrarians (echinoderms, hemichordates) that have a C-terminal RWamide motif (RWamides). Furthermore, precursors of luqin-type neuropeptides typically have a conserved C-terminal motif containing two cysteine residues, although the functional significance of this is unknown. Consistent with the orthology of the neuropeptides and their precursors, phylogenetic and pharmacological studies have revealed that orthologous G-protein coupled receptors (GPCRs) mediate effects of luqin-type neuropeptides in spiralians, ecdysozoans, and ambulacrarians. Luqin-type signaling originated in a common ancestor of the Bilateria as a paralog of tachykinin-type signaling but, unlike tachykinin-type signaling, luqin-type signaling was lost in chordates. This may largely explain why luqin-type signaling has received less attention than many other neuropeptide signaling systems. However, insights into the physiological actions of luqin-type neuropeptides (RYamides) in ecdysozoans have been reported recently, with roles in regulation of feeding and diuresis revealed in insects and roles in regulation of feeding, egg laying, locomotion, and lifespan revealed in the nematode Caenorhabditis elegans. Furthermore, characterization of a luqin-type neuropeptide in the starfish Asterias rubens (phylum Echinodermata) has provided the first insights into the physiological roles of luqin-type signaling in a deuterostome. In conclusion, although luqin was discovered in Aplysia over 30 years ago, there is still much to be learnt about luqin-type neuropeptide signaling. This will be facilitated in the post-genomic era by the emerging opportunities for experimental studies on a variety of invertebrate taxa.
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PMID:Evolution and Comparative Physiology of Luqin-Type Neuropeptide Signaling. 3213