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)

To investigate the role of sensory C-fiber stimulation and tachykinin release in the immediate nasal responses to the sensory irritant acrolein, the upper respiratory tract of the urethan-anesthetized male Fischer 344 rat was isolated via insertion of an endotracheal tube, and acrolein-laden air [2, 5, 10, or 20 parts/million (ppm)] was drawn continuously through that site at a flow rate of 100 ml/min for 50 min. Uptake of the inert vapor acetone was measured throughout the exposure to assess nasal vascular function. Plasma protein extravasation into nasal tissue and nasal lavage fluid was also assessed via injection of Evans blue dye. At 20 ppm, acrolein induced 1) a twofold increase in acetone uptake, indicative of vasodilation, followed by a progressive decline toward basal levels and 2) increased plasma protein extravasation, as indicated by dye leakage into nasal tissue and nasal lavage. These responses were inhibited by capsaicin pretreatment and the neurokinin type 1 antagonist N-acetyltrifluoromethyl tryptophan benzyl ester and were potentiated by the peptidase inhibitors phosphoramidon and captopril, suggesting that these responses were mediated by tachykinin. At lower exposure concentrations, acrolein was without effect on dye leakage but produced vasodilation, as indicated by increased acetone uptake. The responses at the lower concentrations were inhibited by capsaicin pretreatment, implicating nasal sensory C-fiber involvement, but were not influenced by N-acetyltrifluoromethyl tryptophan benzyl ester, phosphoramidon, or captopril, suggesting the involvement of a mediator other than the tachykinins substance P and neurokinin A.
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PMID:Sensory nerve-mediated immediate nasal responses to inspired acrolein. 1056 32

This paper describes the synthesis and physical and biological effects of introducing different substituents at the alpha-position of the tryptophan containing neurokinin-1 receptor antagonist [(R)-2-(1H-indol-3-yl)-1-methyl-1-((S)-1-phenyl-ethylcarbamoyl)-ethyl]-carbamic acid benzofuran-2-ylmethyl ester (CI 1021). The described compounds all exhibit less than 5 nM binding affinities for the human neurokinin-1 receptor and selectivity over the tachykinin NK(2) and NK(3) receptor subtypes. Application of variable temperature nuclear magnetic resonance spectroscopy studies of the amide and urethane protons was utilized to determine the existence of an intramolecular hydrogen bond. This intramolecular hydrogen bond increases the apparent lipophilicity to allow increased central nervous system penetration and pharmacological activity (gerbil foot tap test) in the case of the highest affinity compound [(S)-1-dimethylaminomethyl-2-(1H-indol-3-yl)-1-((S)-1-phenyl-ethylcarbamoyl)-ethyl]-carbamic acid benzofuran-2-ylmethyl ester (PD 174424) over those analogues that could not form an intramolecular hydrogen bond.
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PMID:Utilization of an intramolecular hydrogen bond to increase the CNS penetration of an NK(1) receptor antagonist. 1142 21

In the present study, we investigated whether activation of protease-activated receptor type 2 (PAR-2) with SLIGRL (SL)NH2, a short mimetic agonistic peptide, directly stimulates pepsinogen secretion from gastric-isolated, pepsinogen-secreting (chief) cells. Immunostaining of gastric-dispersed chief cells with a specific anti-PAR-2 antibody demonstrated expression of PAR-2 receptors on membrane and cytoplasm. SL-NH2 and trypsin potently stimulated pepsinogen secretion (EC50 = 0.3 nM) and caused Ca2+ mobilization (EC50 = 0.6 nM). In contrast to SL-NH2, the scramble peptide LSIGRL-NH2 failed to stimulate pepsinogen release. Exposure to SL-NH2 also resulted in ERK1/2 phosphorylation and activation. Exposure of chief cells to phosphotyrosine kinase inhibitors and 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one, a selective MEK inhibitor, significantly reduced secretion induced by SL-NH2. Pepsinogen secretion induced by SL-NH2 was desensitized by pretreating the cells with the mimetic peptide and trypsin, and exposure to SL-NH2 abrogates pepsinogen secretion induced by carbachol and CCK-8, but not secretion induced by secretin and vasointestinal peptide. Exposure to Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2 (substance P) but not to calcitonin gene-related peptide increased pepsinogen release. The neurokinin-1 receptor antagonist, N-acetyl-l-tryptophan 3,5-bis(trifluoromethyl)benzyl ester, inhibited substance P-stimulated pepsinogen secretion, whereas it did not affect secretion induced by SL-NH2. Collectively, these data indicate that PAR-2 is expressed on gastric chief cells and that its activation causes a Ca2+-ERK-dependent stimulation of pepsinogen secretion.
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PMID:PAR-2 modulates pepsinogen secretion from gastric-isolated chief cells. 1274 62

The diuretic helicokinins YFSPWG-amide (Hez KI), VRFSPWG-amide (Hez KII) and KVKFSAWG-amide (Hez KIII) are potent contractants of the isolated gut of the caterpillar Spodoptera frugiperda at doses ranging from 0.1 to 10nM. In comparison, the pentapeptide FSPWG-amide was a full agonist with greatly reduced potency while SPWG-amide and PWG-amide were weak partial agonists. Substitution of individual amino acids in Hez KI with alanine revealed that replacement of the [phenylalanine(2)] residue caused a large fall in potency while replacement of [tryptophan(5)] residue caused complete loss of myogenic activity. The striking fall in potency of YASPWG-amide and the lack of activity of YFSPAG-amide confirm the requirement for aromatic groups in positions 2 and 3 of the core pentapeptide as well as supporting the ideas that the active core of these peptides adopts a beta-turn when interacting with receptors, bringing together the [Phe] and [Trp] residues that are critical for activity. Neither the pentapeptide proctolin nor the potent mammalian gut contractant Substance P were able to cause contraction when applied to caterpillar gut tissue. Incubation of isolated gut tissue in the phosphodiesterase inhibitor theophylline (10-100&mgr;M) caused significant potentiation of the response to applied Hez KI. Conversely, in the presence of the L-type Ca(2+) channel blocker verapamil (10&mgr;M-1mM) or Co(2+) (1-50mM) the contractile effects of Hez KI were attentuated significantly. These data suggest that the gut of S. frugiperda contains G-protein-linked kinin receptors that utilise cyclic AMP as their second messenger system and cause contraction by promoting the entry of extracellular Ca(2+).
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PMID:Structure-activity relationship of contractile effects induced by helicokinins in the isolated gut of the lepidopteran caterpillar Spodoptera frugiperda. 1277 Jan 34

A capillary liquid chromatographic column switching method has been developed for fast and sensitive determination of peptides in water samples. Sample volumes of 1 mL were loaded onto a (320 microm I.D. x30 mm) 10 microm Kromasil C(18) pre-column, providing on-line analyte enrichment, prior to back-flushed elution onto a (320 microm I.D. x150 mm) 3.5 microm Kromasil C(18) analytical column. Loading flow rates of 250 microL/min and a mobile phase composition of acetonitrile/water/trifluoroacetic acid (22/77.9/0.1, v/v) provided a total analysis time of less than 25 minutes for the test peptides angiotensin II, bombesin, bradykinin, corazonin, neurotensin and substance P, using temperature programmed elution. In addition, solvent gradient elution and combined solvent gradient elution and temperature programming were explored. Using on-capillary UV detection at 210 nm resulted in a concentration limit of detection (cLOD) of about 1 ng/mL. The method was validated over the concentration range 1-100 ng/mL, yielding a coefficient of correlation of 0.997 or better. The within-assay ( n=6) and between-assay ( n=6) precisions of peak areas were on average 6% RSD and 5% RSD, respectively. When the method was applied to spiked chlorinated tap water samples, it was found that peptides containing methionine, tryptophan and cystine were oxidized. Identification of the oxidation products of the peptides in hypochlorite-treated water was done with positive electrospray ionization time-of-flight mass spectrometric detection.
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PMID:Trace determination of peptides in water samples using packed capillary liquid chromatography with UV and MS detection and characterization of peptide oxidation products by MS. 1466 72

Neurokinin-1 receptor (NK1R)-expressing neurones that are involved in chemoreception at the retrotrapezoid nucleus (Nattie & Li, 2002b) are also prominent at locations that contain medullary serotonergic neurones, which are chemosensitive in vitro. In medullary regions containing both types, we evaluated their role in central chemoreception by specific cell killing. We injected (2 x 100 nl) (a) substance P-saporin (SP-SAP; 1 microm) to kill NK1R-expressing neurones, (b) a novel conjugate of a monoclonal antibody to the serotonin transporter (SERT) and saporin (anti-SERT-SAP; 1 microm) to kill serotonergic neurones, or (c) SP-SAP and anti-SERT-SAP together to kill both types. Controls received IgG-SAP injections (1 microm). There was no double-labelling of NK1R-immunoreactive (ir) and tryptophan-hydroxylase (TPOH)-ir neurones. Cell (somatic profile) counts showed that NK1R-ir neurones in the SP-SAP group were reduced by 31%; TPOH-ir neurones in the anti-SERT-SAP group by 28%; and NK1R-ir and TPOH-ir neurones, respectively, in the combined lesion group by 55% and 31% (P < 0.001; two-way ANOVA; P < 0.05, Tukey's post hoc test). The treatments had no significant effect on sleep/wake time, body temperature, or oxygen consumption but all three reduced the ventilatory response to 7% inspired CO(2) in wakefulness and sleep by a similar amount. SP-SAP treatment decreased the averaged CO(2) responses (3, 7 and 14 days after lesions) in wakefulness and sleep by 21% and 16%, anti-SERT-SAP decreased the responses by 15% and 18%, and the combined treatment decreased the responses by 12% and 12% (P < 0.001; two-way ANOVA; P < 0.05, Tukey's post hoc test). We conclude that separate populations of serotonergic and adjacent NK1R-expressing neurones in the medulla are both involved in central chemoreception in vivo.
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PMID:Medullary serotonergic neurones and adjacent neurones that express neurokinin-1 receptors are both involved in chemoreception in vivo. 2666 Oct 54

Substance P (SP) has been characterized as an excitatory neurotransmitter and/or neuromodulator in the peripheral and central nervous systems. It is involved in mediating various biological functions such as smooth muscle contraction, neuronal excitation, and pain transmission. Although Lieb et al. reported that intravenous infusion of SP into healthy men led to an increase of paradoxical sleep latency and time awake, little is known about the function and target of SP on sleep-wakefulness cycle in the central nervous system. The ventrolateral preoptic area (vLPO) plays an important role in modulation of sleep-wakefulness cycle. The present study investigated the effect of SP on sleep-wakefulness cycle in the vLPO of rats. Slow wave sleep (SWS) was enhanced after SP was microinjected into bilateral vLPO, while SP receptor antagonist, N-acetyl-l-tryptophan 3,5-bis(trifluoromethyl)-benzyl ester, led to the opposite effect. The effect induced by SP was blocked by U73122, a phospholipase C inhibitor. In addition, 3-mercaptopropionic acid, a glutamic acid decarboxylase inhibitor that inhibits gamma-aminobutyric acid (GABA) synthesis and release, blocked the SP-induced sleep-promoting effect in the vLPO. These results indicate that SP has sleep-promoting effect in the vLPO possibly by GABAergic neurons.
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PMID:Substance P promotes sleep in the ventrolateral preoptic area of rats. 1552 48

Neurokinin 3 receptors (NK3-Rs) are expressed in the supraoptic nucleus (SON), and SON is innervated by substance P (SP)-expressing A1 neurons in the medulla. Because SP stimulates vasopressin (VP) and oxytocin release from explants of the hypothalamo-neurohypophyseal system (HNS), two hypotheses were tested: (1) SP-stimulated VP release is mediated by NK3-Rs, and (2) stimulation of the A1 pathway by hypotension activates SON NK3-Rs. Senktide, an NK3-R agonist, stimulated VP release from HNS explants, but neither a neurokinin 1 receptor antagonist [L732,138 (N-acetyl-L-tryptophan 3,5-bis(tri-fluoromethyl)benzyl ester)] nor two NK3-R antagonists (SB222200 and SB235375) prevented SP-stimulated VP release. Because the affinity of these antagonists for rat NK-Rs may limit their efficacy, NK3-R internalization was used to assess the ability of SP to activate SON NK3-Rs. Senktide, SP, or vehicle was microinjected above SON. The brain was perfused 5 min after injection and stained for NK3-R immunoreactivity. Using confocal microscopy, the number of NK3-R-immunoreactive (-IR) endosomes was counted in a 5.6(2) mu region of cytoplasm in SON neurons. Senktide, but not SP or vehicle, significantly increased the number of NK3-R-IR endosomes in the cytoplasm. When hypotension was induced with hydralazine, NK3-R internalization was observed within 5 min (p < 0.005). A decrease in cytoplasmic NK3-R immunoreactivity was observed within 15 min of hypotension. Unexpectedly, both senktide and hypotension resulted in translocation of NK3-R-IR immunoreactivity to the nucleus. Thus, although these studies do not identify SP as the NK3-R ligand, they do provide evidence for hypotension-induced release of an endogenous tachykinin in SON and evidence suggesting a role for NK3-Rs in transcription regulation.
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PMID:Role of neurokinin 3 receptors in supraoptic vasopressin and oxytocin neurons. 1553 80

Ghrelin increases electrically evoked, neuronally mediated contractions of rat isolated forestomach, a prokinetic-like activity. Since the nerve type sensitive to ghrelin is unclear, we examined the activity of ghrelin in the presence of antagonists at receptors for the main gastric motor neurotransmitters. Electrical field stimulation (EFS; 5 Hz, 0.5 ms, +/-50 V, 30 s every 3 min) of circular muscle preparations evoked tetrodotoxin 1 microM-sensitive responses, consisting of a small initial contraction followed by a further contraction or more usually, by muscle relaxation. Termination of EFS evoked a large rapidly developing after-contraction. Atropine 1 microM prevented contractions during EFS, increased any relaxations and prolonged the after-contractions. Nomega-Nitro-L-arginine-methyl-ester-hydrochloride (L-NAME) 0.3 mM prevented relaxations during EFS, changing the triphasic response into a monophasic contraction. The tachykinin NK1 and tachykinin NK2 receptor antagonists N-acetyl-L-tryptophan-3,5-bistrifluoromethyl-benzyl-ester (L-732,138 1 microM) and Cyclo[Gln-Trp-Phe-Gly-Leu-CH2N(CH3)-Leu] (MDL-29,913 1 microM) each reduced EFS-evoked relaxations; the latter also reduced the after-contractions. The tachykinin NK3 receptor antagonist (-)-(S)-N-(alpha-ethylbenzyl)-3-(carboxymethoxy)-2-phenylquinoline-4-carboxamide (SB-235375, 0.1 microM) had no effects. The combination of tachykinin NK(1,2,3) receptor antagonists reduced the after-contractions and abolished relaxations during EFS, replacing this with a contraction. In control tissues, ghrelin 1 microM increased EFS-induced contractions and tended to reduce any relaxations. In the presence of atropine 1 microM, L-NAME 0.3 mM or the tachykinin receptor antagonists (as above), ghrelin 1 microM increased any EFS-induced contraction but in the presence of atropine had no effects on EFS-evoked relaxations. We conclude that EFS evokes responses mediated by acetylcholine, nitric oxide and tachykinins. Ghrelin facilitates both cholinergic and tachykininergic excitatory pathways, consistent with activity within the enteric nervous system and possibly the vagus nerve.
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PMID:The prokinetic-like activity of ghrelin in rat isolated stomach is mediated via cholinergic and tachykininergic motor neurones. 1685 71

Brain edema and swelling is a critical factor in the high mortality and morbidity associated with traumatic brain injury (TBI). Despite this, the mechanisms associated with its development are poorly understood and interventions have not changed in over 30 years. Although neuropeptides and neurogenic inflammation have been implicated in peripheral edema formation, their role in the development of central nervous system edema after brain trauma has not been investigated. This study examines the role of the neuropeptide, substance P (SP), in the development of edema and functional deficits after brain trauma in rats. After severe diffuse TBI in adult male rats, neuronal and perivascular SP immunoreactivity were increased markedly. Perivascular SP colocalized with exogenously administered Evans blue, supporting a role for SP in vascular permeability. Inhibition of SP action by administration of the neurokinin-1 (NK1) antagonist, N-acetyl-L-tryptophan, at 30 mins after trauma attenuated vascular permeability and edema formation. Administration of the NK1 antagonist also improved both motor and cognitive neurologic outcomes. These findings suggest that SP release is integrally linked to the increased vascular permeability and edema formation after brain trauma, and that treatment with an NK1 receptor antagonist reduces edema and improves neurologic outcome.
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PMID:Substance P is associated with the development of brain edema and functional deficits after traumatic brain injury. 1943 11


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