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

Depolarization has been shown to alter the biosynthesis of a number of neurotransmitters and neuromodulators. In the rat superior cervical ganglion (SCG), for example, depolarization has been reported to increase catecholamine biosynthesis and to decrease the level of substance P. We have recently found that, although the level of vasoactive intestinal peptide (VIP)-like immunoreactivity (IR) is normally low in the SCG, it increases significantly 48 hr after adult ganglia are deafferented in situ or placed in organ culture. Both manipulations decrease electrical activity of postganglionic neurons. To determine whether the increases in ganglionic VIP-IR could be a consequence of decreased depolarization of sympathetic neurons, the effect of depolarization on the expression of VIP-IR was examined in organ cultures of neonatal and adult SCG. Depolarization with elevated K+ (30 mM) or veratridine (1.5 microM) amplified, rather than blocked, the increases in VIP-IR content seen after 24 hr. Further, it increased the number of detectable VIP-IR neuronal cell bodies and processes. The stimulatory effects of veratridine were prevented by TTX. Since similar changes in expression of VIP-IR were evident in dissociated cell cultures of the SCG, cell-cell interactions requiring intact ganglionic architecture are not necessary for altered peptide expression. Elevating the concentration of Mg2+ blocked the ability of K+ and veratridine to increase VIP-IR in dissociated cell culture, raising the possibility that the effects of depolarization on VIP-IR are mediated by increased Ca2+ entry. The depolarizing conditions that increased VIP-IR also increased substance P-IR. While higher concentrations of veratridine (50 microM) blocked the elevation of both VIP- and substance P-IR induced by explantation, they produced significant neuronal death. Since depolarization with either 30 mM KCl or 1.5 microM veratridine increases expression of VIP-IR in neonatal and adult ganglia, decreased depolarization is unlikely to cause the increases in VIP- and substance P-IR that occur in culture. Furthermore, our data raise the possibility that sympathetic nerve activity in vivo can increase expression of these peptides.
 ...
PMID:Depolarization increases vasoactive intestinal peptide- and substance P-like immunoreactivities in cultured neonatal and adult sympathetic neurons. 138 75

The hypothalamo-neurohypophyseal tract is known to contain the classical neurohypophyseal hormones vasopressin and oxytocin. Additionally, dynorphin, methionine- and leucine-enkephalin, cholecystokinin (CCK), corticotropin-releasing factor (CRF), and galanin are co-stored with vasopressin and/or oxytocin. Recent immunohistochemical studies have revealed the existence of a low to moderate number of substance P-, vasoactive intestinal peptide (VIP)-, neuropeptide Y (NPY)- and somatostatin-immunoreactive nerve fibers within the rat neurohypophysis. VIP-, substance P- and NPY-immunoreactive fibers were distributed throughout the organ, whereas somatostatin-immunoreactive fibers were present in the proximal part of the organ. The positive nerve endings were either large in size resembling classical nerve terminals related to perivascular spaces, or smaller similar to peptidergic fibers as described in the CNS. These results indicate that these neuropeptides may be either co-stored with the classical neurohypophyseal hormones or contained in another system of afferents to the organ. The probably distinct functional roles of these neuropeptides in the physiology of the neurohypophysis are discussed.
 ...
PMID:Non-vasopressinergic, non-oxytocinergic neuropeptides in the rat hypothalamo-neurohypophyseal tract: experimental immunohistochemical studies. 138 83

We investigated the possibility of nitric oxide (NO), a powerful vasodilator agent, being synthesized by perivascular nerve fibres. Immunoreactivity and catalytic activity of the NO synthesizing enzyme, NO synthase (NOS), were demonstrated in perivascular nerve fibres of blood vessels receiving autonomic vasodilator innervation, but not of those innervated exclusively by vasoconstrictor nerve fibres. Double-labelling techniques allowed identification of NOS-containing nerve fibres as belonging to the vasoactive intestinal peptide (VIP)/acetylcholine-containing class whereas noradrenergic and substance P-containing perivascular fibres were devoid of NOS. We suggest that, in addition to its endothelial source, NO is a neuronal co-mediator of VIP/cholinergic vasodilation.
 ...
PMID:Nitric oxide synthase in VIP-containing vasodilator nerve fibres in the guinea-pig. 138 69

The present work was undertaken to determine by immunocytochemical methods which of the putative enteric neurotransmitters are contained in axons supplying the guinea-pig taenia coli and what proportion of axons is accounted for by the presence of these substances. Numerous fibres displayed immunoreactivity for dynorphin (DYN), enkephalin (ENK), gamma-aminobutyric acid (GABA), nitric oxide synthase (NOS), substance P (SP) and vasoactive intestinal peptide (VIP), but, in contrast to other gut regions, fibres showing immunoreactivity for gastrin-releasing peptide, galanin and neuropeptide Y were rare in the taenia. Fibres reactive for calbindin, calcitonin gene-related peptide, cholecystokinin, 5-hydroxytryptamine and somatostatin were also rare. Tyrosine hydroxylase-like immunoreactivity (TH-LI) was present in numerous fibres that disappeared after extrinsic denervation, a procedure that did not detectably affect any of the other major groups of fibres. Simultaneous staining of extrinsically denervated preparations revealed that SP-LI and VIP-LI were located in separate fibres, and ultrastructural studies showed these to be 58% and 33% of intrinsic fibres supplying the muscle. Immunoreactivity for the general marker, neuron-specific enolase, was located in 95-98% of axons. ENK-LI and DYN-LI were in the same axons, and similar proportions of the fibres with either SP-LI or VIP-LI, about 85%, contained immunoreactivity for ENK and DYN. All VIP-LI fibres, but no SP-LI fibres, were reactive for NOS. The results imply that the taenia of the guinea-pig caecum is innervated by two major groups of enteric neurons: (i) excitatory neurons that contain ACh, SP, other tachykinins, and, in most cases, DYN-LI and ENK-LI; and (ii) inhibitory neurons that contain NOS-LI, VIP-LI, in most cases, the two opioids and, quite probably, ATP as a transmitter. GABA-LI is contained in a smaller population of intrinsic axons. Even though the taenia represents one of the simplest tissues for examining transmission from enteric neurons to intestinal muscle, it shares some of the complexity of other regions, in that four major axon types supply the muscle and both the enteric excitatory and enteric inhibitory neurons contain multiple transmitters.
 ...
PMID:Light- and electron-microscopic immunochemical analysis of nerve fibre types innervating the taenia of the guinea-pig caecum. 138 81

The effect of neuropeptide Y (NPY) was tested on isolated guinea pig trachea. At 30 nM, NPY induced a weak but significant contractile response which was on average less than 6% of responses elicited by standard spasmogens. This myotropic action of NPY was blocked by indomethacin. In addition to its contractile activity, NPY greatly reduced the maximal response to vasoactive intestinal peptide (VIP), noradrenaline (NA), substance P (SP) and 5-hydroxytryptamine (5-HT), without affecting their pD2 values. However, NPY did not influence the response induced by histamine and carbamylcholine. Pretreatment of tracheal spirals with indomethacin (10(-6) M) abolished the NPY-evoked inhibition of VIP, SP and 5-HT responses but failed to reduce the action of NPY on NA-elicited relaxation. This latter effect was however blocked in the presence of tetrodotoxin. In conclusion, NPY inhibits responses elicited by various agonists in the guinea pig trachea. This effect seems to be mediated at both pre- and postjunctional levels. The postjunctionally mediated inhibitory action of NPY appears to be expressed especially with agents that generate prostaglandins concomitantly with inducing their response. In contrast, the NPY-evoked inhibition of NA-evoked relaxation seems to be mediated via a prejunctional mechanism.
 ...
PMID:Inhibitory action of neuropeptide Y on agonist-induced responses in isolated guinea pig trachea. 138 64

The levels of several regulatory peptides were measured in peripheral plasma samples from individuals with chronic cardiac failure (CCF) and matched controls in both the resting state and during a short period of maximal exercise. Basal levels of noradrenaline (NA; 705 +/- 114 vs 195 +/- 54 ng.l-1; mean +/- SEM; P < 0.05), plasma renin activity (PRA; 12.9 +/- 2.9 vs 2.1 +/- 0.3 ng AI ml-1.h-1; P < 0.05) and aldosterone (ALDO; 325 +/- 49 vs 87 +/- 8 ng.l-1; P < 0.05) were all raised in the patients with CCF, and increased further with exercise. Basal circulating levels of atrial natriuretic peptide (ANP) were also significantly higher in the CCF group compared to controls (136 +/- 35 vs 27 +/- 5 ng.l-1; P < 0.01), but the response to exercise was attenuated, so that at peak exercise, no significant difference was observed. Basal circulating levels of gastrin-releasing peptide (GRP) (29 +/- 4 vs 40 +/- 4 ng.l-1; P < 0.05) and secretin (13 +/- 1 vs 32 +/- 4 ng.l-1; P < 0.05) were significantly lower in the CCF group when compared to controls and there was no significant change in the levels of either peptide with exercise. Levels of neurokinin A (NKA), neuropeptide Y (NPY) and neurotensin (NT) were somewhat higher in patients, but the differences were not significant, and there were no changes during exercise. There were also no significant differences in the levels of vasoactive intestinal peptide (VIP), glucose-dependent insulinotropic polypeptide (GIP), insulin or glucagon in either experimental group both before and during exercise. We have therefore identified different circulating levels of certain regulatory peptides in patients with CCF, but the significance of these remains unclear.
 ...
PMID:Regulatory peptides in the plasma of patients with chronic cardiac failure at rest and during exercise. 139 15

A role for peptidergic nerves in the adult respiratory distress syndrome (ARDS) was examined by radioimmunochemically quantifying neuropeptides in pulmonary edema (PE) fluids from seven patients with ARDS and six patients with PE from congestive heart failure (CHF). The PE fluid mean concentrations of substance P (SP) and gastrin-releasing peptide (GRP) were significantly higher in ARDS (0.59 +/- 0.29 SD and 0.10 +/- 0.03 nM, respectively, P < 0.001 for both) than in CHF (0.19 +/- 0.08 and 0.04 +/- 0.01), whereas no difference was detected between the mean levels of vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) in the two forms of PE. Mean alveolar fluid concentration of SP was 8.7 nM (range 2.1-20.5 nM, N = 4) in sheep with acute lung injury from intravenous Pseudomonas aeruginosa, but was undetectable in sheep with balloon-induced high left atrial pressure simulating CHF (N = 2) or control sheep (N = 2). Pulmonary lymphatic clearance of SP, which reflected the rate of generation of SP in the lungs, attained a maximum of 25-95 pmol/h in sheep given P. aeruginosa intravenously, but was detected in only one of four control sheep at a lower level. Some pulmonary neuropeptides thus are released locally by acute lung injury and may contribute to endothelial and/or epithelial abnormalities underlying the altered capillary-alveolar permeability in ARDS.
 ...
PMID:Neuropeptides in pulmonary edema fluid of adult respiratory distress syndrome. 142 25

Helospectin I and II are two non-amidated, VIP-like peptides, isolated from the salivary gland venom of the lizard Heloderma horridum. The lower esophagus of cat, sheep and man was analyzed for helospectin-like immunoreactivity. Immunocytochemistry revealed helospectin-immunoreactive nerve fibers in the muscle layers, submucosa and mucosa of all species studied. In myenteric ganglia helospectin-immunoreactive nerve fibers and nerve cell bodies could be seen. Double immunostaining for helospectin and vasoactive intestinal peptide (VIP) revealed their coexistence in nerve fibers and cell bodies throughout the lower esophagus of all species tested. Double immunostaining for helospectin and neuropeptide Y revealed their coexistence in nerve fibres surrounding vascular and non-vascular smooth muscle. In the cat and sheep (but not in man) a subpopulation of the helospectin/VIP-containing fibers stored, in addition, substance P. The helospectin-immunoreactive material in the esophagus probably constitutes a novel neuropeptide. The distribution of the VIP/helospectin-immunoreactive neurons and fibers indicates their possible involvement in the regulation of motor and secretory activities.
 ...
PMID:Helospectin-like immunoreactivity in the esophagus. 143 80

GABAergic and cholinergic synaptosomes from rat cerebral cortex were isolated by a magnetic immunoaffinity technique, i.e. immunomagnetophoresis. These subpopulations were extracted and subjected to radioimmunoassay for four neuropeptides: Neuropeptide Y (NPY); vasoactive intestinal peptide (VIP); substance P (SP); and somatostatin (SRIF). In each of the sub-populations three of the four peptides were enriched in the sorted fraction compared with the mother fraction with respect to the cytosolic marker lactate dehydrogenase (LDH). In the GABAergic sub-population the order was SP > SRIF > NPY > or = VIP whilst in the cholinergic sub-population they were enriched in the order VIP > or = NPY > SP > SRIF. The presence of NPY has not previously been reported in cortical cholinergic neurons.
 ...
PMID:The presence of neuropeptides in GABAergic and cholinergic rat cerebrocortical synaptosome sub-populations. 145 55

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a new member of the secretin/glucagon peptides family, being most homologous to vasoactive intestinal peptide (VIP). The present study was designed to investigate a possible effect of PACAP on the rat gastrointestinal smooth muscle in vitro. We demonstrated that 1) PACAP reduced basal smooth-muscle contractions in all portions of the gastrointestinal tract, but the effect of VIP was region-specific. The inhibitory effect of PACAP in midcolon was approximately 100 times greater than that of VIP. 2) PACAP significantly inhibited smooth-muscle contractions induced by acetylcholine or carbachol. The inhibitory effect of PACAP was not affected by hexamethonium and was additive to the inhibitory effect of atropine and pirenzepine. 3) PACAP inhibited smooth-muscle contractions induced by substance P, cholecystokinin, and galanin, even after atropine treatment. Although the exact mechanism of the inhibitory action of PACAP remains to be clarified, PACAP appears to exert its effect in the rat at a site other than muscarinic receptors, probably through a direct effect on gastrointestinal smooth muscle in vitro.
 ...
PMID:Pituitary adenylate cyclase-activating polypeptide relaxes rat gastrointestinal smooth muscle. 152 72


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>