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 effect of ozone (3 ppm, 15-120 min) on bronchial reactivity in the guinea-pig was studied. Ozone induced marked (6-250-fold) bronchial hyperreactivity (BHR) to a range of inhaled, but not intravenous bronchoconstrictors. The degree of BHR was related to the duration of prior ozone exposure. The glutathione redox status was shifted to a more oxidized state in lung after 120 min ozone treatment, although no changes were found in the energy status of lung tissue, as judged by the concentrations of adenosine phosphates. Ascorbic acid pretreatment prevented BHR induced by 30 min ozone exposure. Neutral endopeptidase inhibitors elicited BHR to both substance P and histamine, but did not further enhance bronchoconstriction to substance P after ozone exposure for 120 min. Neither mepyramine, fentanyl, indomethacin nor a 5-lipoxygenase inhibitor (BW B70C), given prior to ozone exposure prevented the induction of BHR to histamine. Atropine or bilateral vagotomy reduced BHR after a 120-min, but not 30-min exposure to ozone. We conclude that in the guinea-pig, ozone induces non-specific, route-dependent BHR by oxidative injury, reducing airway NEP activity and enhancing the cholinergic and peptidergic component to bronchoconstriction. Neither cyclooxygenase nor 5-lipoxygenase products appear to play a role in ozone-induced BHR in this animal model.
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PMID:Mechanisms contributing to ozone-induced bronchial hyperreactivity in guinea-pigs. 137 22

Neutral endopeptidase 24.11 contains an active site arginine believed to function in substrate binding. This arginine is thought to form an ionic interaction with the COOH-terminal carboxylate of NEP substrates. The functionality of arginine 102 has been investigated by using site-directed mutagenesis to produce mutants in which this residue was converted to a lysine, glycine, glutamine, or glutamate. All of the mutants exhibited essentially full activity as determined with a synthetic peptide amide, glutaryl-Ala-Ala-Phe-4-methoxy-2-naphthylamide. In contrast, activity was detected only with the wild-type enzyme and the lysine mutant using a synthetic substrate containing a free COOH-terminal carboxylate, dansyl-Gly-Trp-Gly. Inhibition studies with the physiologically active peptide substrates substance P, endothelin, and angiotensin I, as well as substance P free acid, [D-Ala2,Leu5]enkephalin, and [D-Ala2,Leu5]enkephalinamide indicated a lack of importance of arginine 102 in substrate binding. With [D-Ala2,Met5]enkephalin and the chemotactic peptide, N-formyl-Met-Leu-Phe, a significant decrease in affinity is observed with the arginine 102 mutants. These results suggest that the contribution of arginine 102 to substrate binding is dependent upon the strength of other subsite interactions. Examination of dipeptides as inhibitors indicates that the nature and orientation of the P'2 residue is important in determining the strength of the interaction of arginine 102 with its substrates.
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PMID:Analysis of the importance of arginine 102 in neutral endopeptidase (enkephalinase) catalysis. 137 21

Kinins and substance P have been implicated in the pathogenesis of inflammatory arthritis by virtue of their abilities to induce vasodilation, edema, and pain. The relative biological potencies of these peptides in vivo would depend at least in part upon their rates of catabolism in the joint. We hypothesized that human synovial lining cells may regulate intraarticular levels of kinins and neuropeptides via degradation by cell surface-associated peptidases. We exposed intact human synovial fibroblasts to kinins and substance P, in the presence or absence of specific peptidase inhibitors, and measured the amount of intact substrate remaining and degradation product(s) generated over time. Aminopeptidase M (AmM; EC 3.4.11.2), neutral endopeptidase-24.11 (NEP-24.11; EC 3.4.24.11), and dipeptidyl(amino)peptidase IV (DAP IV; EC 3.4.14.5) were identified on the cell surface of synovial cells. Bradykinin degradation was due entirely to NEP-24.11 (1.39 +/- 0.29 nmol/min per well). Lysylbradykinin was also degraded by NEP-24.11 (0.80 +/- 0.19 nmol/min per well); however, in the presence of phosphoramidon, AmM-mediated conversion to bradykinin (3.74 +/- 0.46 nmol/min per well) could be demonstrated. The combined actions of NEP-24.11 (0.93 +/- 0.15 nmol/min per well) and DAP IV (0.84 +/- 0.18 nmol/min per well) were responsible for the degradation of substance P. AmM (2.44 +/- 0.33 nmol/min per well) and NEP-24.11 (1.30 +/- 0.45 nmol/min per well) were responsible for the degradation of the opioid peptide, [Leu5]enkephalin. The identity of each of the three peptidases was confirmed via synthetic substrate hydrolysis, inhibition profile, and immunological identification. The profiles of peptidase enzymes identified in cells derived from rheumatoid and osteoarthritic joints were identical. These data demonstrate the human synovial fibroblast to be a rich source of three specific peptidases and suggest that it may play a prominent role in regulating peptide levels in the joint.
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PMID:Cultured human synovial fibroblasts rapidly metabolize kinins and neuropeptides. 138 26

To determine whether exogenously administered neutral endopeptidase (NEP; enkephalinase, EC 3.4.24.11) inhibits the substance P-induced increase in vascular permeability in the skin, we examined the effects of recombinant human NEP on plasma extravasation induced by intradermal injection of substance P in guinea pig skin. Injection of substance P (2.5 X 10(-8) M) induced significant plasma extravasation in the skin (53 +/- 4 mm2 of Evans blue extravasation; mean +/- 1 SEM). In vitro incubation of substance P with recombinant human NEP prior to injection prevented the substance P-induced plasma extravasation in the skin in a dose-dependent fashion. Intradermal preinjection of recombinant human NEP partially inhibited plasma extravasation induced by subsequent injection of substance P (52 +/- 9% of the control without NEP). The H1 and H2 histamine antagonists pyrilamine and cimetidine, and a muscarinic antagonist, atropine, had no effects on substance P-induced responses. Two products of substance P degradation by NEP containing the carboxy-terminal portion, substance P7-11 and substance P8-11, were also without effect. These findings suggest that recombinant human NEP can attenuate substance P-induced increases in vascular permeability in guinea pig skin and, therefore, may be useful in treating dermatologic disorders in which abnormal responses to substance P or other neuropeptides cleaved by NEP may occur.
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PMID:Recombinant neutral endopeptidase attenuates substance P-induced plasma extravasation in the guinea pig skin. 169 12

Characterization of the distribution of the peptide-degrading enzyme neutral endopeptidase-24.11 (E.C. 3.4.24.11; NEP; enkephalinase) in the rat brainstem was examined by means of a unique fluorescent histochemical method. Enzyme staining was completely blocked by three potent NEP inhibitors (thiorphan, phosphoramidon, and JHF-26) at a concentration of 50 nM, supporting the specificity of this method to visualize sites of NEP activity selectively. At all levels of the brainstem, NEP was localized to cell bodies, cell processes or terminal-like fields and was localized to more than 90 distinct nuclei or subnuclei. In the mesencephalon these included the central gray, cuneiform n., dorsal and lateral tegmental n., inferior colliculus, interpeduncular n., lateral and medial geniculate n., central linear raphe n., mesencephalic n. of the trigeminal nerve, mammillary nuclei, occulomotor n., red n., superior colliculus, ventral n. of the lateral lemniscus, substantia nigra-ventral tegmental area, and the zona incerta. In the pons, NEP staining was restricted to fewer regions or nuclei, including the dorsal and ventral cochlear n., facial n., motor trigeminal n., principal sensory trigeminal n., parabrachial nuclei, pontine n., the oral and caudal pontine reticular n., pontine olivary nuclei, several pontine tegmental nuclei, pontine raphe nuclei, and the trapezoid n. In the cerebellum, staining was localized largely to the granule cell layer of the cerebellar cortex. Scattered staining was observed in the molecular cell layer. The medulla contained extensive NEP staining localized to nuclei that included the ambiguous n., dorsal motor n. of the vagus, hypoglossal n., inferior olivary n., prepositus hypoglossus n., solitary tract n., nuclei of the spinal tract of the trigeminal n., and the lateral, medial, and superior vestibular nuclei. Nuclei of the medullary reticular formation that were also richly stained for NEP included the raphe magnus n., raphe obscurus n., raphe pallidus n., dorsal, lateral, and ventral reticular nuclei of the medulla, and the gigantocellular, lateral paragigantocellular, linear, paramedian and parvicellular reticular nuclei. The widespread distribution of NEP in the brainstem suggests the existence of a number of functional systems, including the pathways involved in the mechanisms of pain and analgesia, which are potential targets of NEP inhibitors. In most regions, the distribution of NEP closely overlapped with that reported for the enkephalins, and showed a more restricted overlap with the reported distribution of substance P.
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PMID:Fluorescent histochemical localization of neutral endopeptidase-24.11 (enkephalinase) in the rat brainstem. 169 88

In halothane-anesthetized and -ventilated cynomologus macaque monkeys, the effects of administering vehicle (n = 3) or the neutral endopeptidase inhibitor N-[L-(1-carboxy-2-phenyl)ethyl]-L-phenylalanyl-beta-alanine (16 mg/kg, n = 5; or 100 mg/kg, n = 3, intravenously) was examined. Cisternal CSF aliquots were examined by radioimmunoassay: 1) for Met enkephalin; 2) after trypsin and carboxypeptidase B treatment for encrypted enkephalin (X-ENK); 3) for substance P; and 4) for unmetabolized drug. Similar measures were carried out in femoral artery and femoral venous plasma, except that substance P was not assayed. In CSF, prior to drug, low, but measurable levels of enkephalin (61 pg/ml), X-ENK (285 pg/ml) and substance P (16 pg/ml) were observed. Vehicle-injected animals showed no change from baseline levels over a 4-hr sampling period in either plasma or CSF levels. In contrast, following 16 mg/kg, in CSF, there was a significant 9-fold increase in MET and 11-fold increase in X-ENK at 30 min. CSF-substance P levels rose also by a factor of 2, with the peak effect observed at 60 min. All levels displayed a significant reduction by 4 hr. There was no statistical difference between the maximum effects observed with either the 16- or 100-mg/kg dose. Plasma peptide levels of enkephalin and X-ENK were not altered by drug. CSF displayed significant drug levels by 30 min, which were between 0.1 and 1% of levels observed concurrently in plasma.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of [N-(L-(1-carboxy-2-phenyl)ethyl]-L-phenylalanyl-beta-alanine (SCH32615), a neutral endopeptidase (enkephalinase) inhibitor, on levels of enkephalin, encrypted enkephalins and substance P in cerebrospinal fluid and plasma of primates. 170 28

We examined the role of substance P (SP) and neurokinin A (NKA) in the postmortem bronchoconstriction in guinea pig lungs using isolated lungs superfused via the trachea. Airway opening pressure (Pao) during superfusion was monitored and the superfusate collected for analysis of SP- and NKA-like immunoreactivities (SP-LI and NKA-LI, respectively). Peak Pao (39.0 +/- 3.9 cmH2O) was reached 10 min after starting superfusion; Pao decreased slowly thereafter, reaching only 9.9 +/- 2.2% of the peak value 2 h after starting superfusion (P less than 0.005); 12.6 +/- 2.6 and 34.0 +/- 9.7 fmol of SP-LI and NKA-LI, respectively, were found in the fraction corresponding to 10-20 min of superfusion. Recovered immunoreactivities decreased to 5.2 +/- 0.3 and 9.3 +/- 1.8 fmol of SP-LI and NKA-LI, respectively, in the fraction corresponding to 110-120 min of superfusion (P less than 0.05). Inhibition of neutral endopeptidase with thiorphan resulted in significantly greater increases in Pao (P less than 0.005) and augmentation of the recovery of SP-LI and NKA-LI (P less than 0.05 and P less than 0.001, respectively). Capsaicin treatment of animals 7-10 days before the removal of their lungs abolished the increase in Pao during superfusion and resulted in a significant decrease in the amount of SP-LI and NKA-LI recovered. Our data confirm that tachykinin release occurs during postmortem bronchoconstriction in guinea pig lungs and, furthermore, that tachykinin degradation by NEP modulates the intensity of this response.
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PMID:Tachykinin recovery during postmortem bronchoconstriction in guinea pig lungs. 170 33

Neutral endopeptidase (NEP; EC 3.4.24.11) is well recognized as a regulatory peptidase for substance P (SP)-induced responses in various tissues. To determine whether NEP regulates SP-induced activation of human neutrophils, we examined the effect of the NEP inhibitor phosphoramidon on SP-induced superoxide generation and chemotaxis in human blood neutrophils. SP (10(-6)-10(-4) M) induced superoxide generation and chemotaxis in the neutrophils dose dependently. The NEP inhibitor enhanced the SP-induced responses. Thus, phosphoramidon (10(-6) M) shifted the dose-response curves of SP-induced superoxide generation and chemotaxis of the neutrophils to the left by 0.5-0.6 log. Phosphoramidon prevented the hydrolysis of SP by the neutrophils, the NEP activity of the neutrophils being assessed as 125 +/- 13 pmol of SP/min/10(6) cells. The N-terminal peptide SP (up to 3 x 10(-4) M), which was a major degrading product by NEP of the neutrophils, did not activate the neutrophils. We conclude that NEP modulates SP-induced activation of human neutrophils.
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PMID:Neutral endopeptidase modulates substance P-induced activation of human neutrophils. 171 1

We have previously shown that neutral endopeptidase (NEP; EC 3.4.24.11) regulates neuropeptide-induced responses. Recently, Pierart et al. reported that NEP degraded purified interleukin-1 (IL-1) using thymocyte proliferation assay. Since IL-1 is an important cytokine in the immune response and inflammation, we have assessed whether NEP hydrolyzes recombinant human IL-1 beta using three assay systems (bioassay, immunoassay, and HPLC analysis). NEP on the NALM-6 cells (both intact cells and the solubilized plasma membrane fraction) efficiently hydrolyzed Met5-enkephalin and substance P. However, NEP did not significantly decrease the amount of rhIL-1 beta assessed by the growth inhibitory activity of a human melanoma, by the immunoassay, or by the direct analysis on HPLC. Therefore, we conclude that NEP does not significantly hydrolyze rhIL-1 beta. Our results suggest that, in contrast to the regulatory role of NEP in neuropeptide-induced responses, NEP is not a regulatory enzyme for IL-1-induced responses.
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PMID:Neutral endopeptidase (EC 3.4.24.11) does not hydrolyze recombinant human interleukin-1 beta. 171 45

The common acute lymphoblastic leukemia antigen (CALLA, CD10), which is expressed on early lymphoid progenitors and neutrophils, is the zinc metalloprotease, neutral endopeptidase 24.11 (NEP, "enkephalinase"). The CD10 cell surface enzyme is known to hydrolyze a variety of biologically active peptides including met-enkephalin, formyl-met-leu-phe (f-MLP), and substance P. These three CD10/NEP substrates induce the migration and aggregation of neutrophils, suggesting that each of the peptides can function as a mediator of neutrophil inflammatory responses. Recently, inhibition of CD10/NEP was found to reduce the concentration of metenkephalin needed to activate human and invertebrate granulocytes by several orders of magnitude. Herein we show that f-MLP and substance P induce rapid changes in neutrophil morphology, migration, and adhesion molecule expression, including upregulation of Mo1 (CD11b/CD18) and shedding of LAM-1 (also known as LECAM-1, Leu8, or TQ-1, the human homologue of murine gp100MEL14). Importantly, these coordinated changes are potentiated by inhibition of cell surface CD10/NEP enzymatic activity. Neutrophil cell surface CD10/NEP enzymatic activity is also shown to be regulated by the activation state of the cell during the time period in which the enzyme has its most pronounced effects. These results suggest that in neutrophils, CD10/NEP functions to control responsiveness to multiple inflammatory peptides.
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PMID:CD10 (CALLA)/neutral endopeptidase 24.11 modulates inflammatory peptide-induced changes in neutrophil morphology, migration, and adhesion proteins and is itself regulated by neutrophil activation. 171 72


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