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)

In conscious rats, the intrathecal (i.t.) injection of endothelin-1 (ET-1; 65-650 pmol) and endothelin-3 (ET-3; 162-650 pmol) produced dose-dependent increases of mean arterial blood pressure (MAP) accompanied by either a tachycardia or a bradycardia. A number of animals died by a sudden respiratory arrest. ET-3 was less toxic and less potent than ET-1 on MAP and heart rate (HR) while BQ-3020, a selective ETB agonist, had no toxic effect and exhibited only a weak pressor effect on blood pressure. The prior i.t. injection of 65 nmol BQ-123, a selective ETA receptor antagonist, blocked both the cardiovascular and toxic effects of ET-1 but failed to modify the cardiovascular effect evoked by i.t. substance P (6.5 nmol) or to cause intrinsic cardiovascular and toxic effects. While the pressor response to ET-1 was significantly inhibited after i.v. injection of phentolamine, the bradycardia was blocked by pentolinium. The cardiovascular response to ET-1 was, however, unaffected in rats either sympathectomized with 6-hydroxydopamine or pretreated with capsaicin. Furthermore, big ET-1 (100 pmol) caused toxic effects and delayed cardiovascular changes which were prevented by the prior i.t. administration of either BQ-123 (65 nmol) or 100 nmol phosphoramidon, an endothelin-converting enzyme (ECE) inhibitor. These results suggest: (1) that the cardiovascular and toxic effects of i.t. endothelins are mediated by ETA receptors in the rat spinal cord; (2) that the pressor response and bradycardia are likely due to the activation of the sympatho-adrenal nervous system and to a vagal reflex mechanism, respectively; and (3) that a phosphoramidon-sensitive ECE converts big ET-1 to ET-1 in the rat spinal cord.
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PMID:Cardiovascular effects of intrathecally administered endothelins and big endothelin-1 in conscious rats: receptor characterization and mechanism of action. 752 26

An endo-acting proline-specific oligopeptidase (prolyl oligopeptidase [POPase], EC 3.4.21.26) was purified to homogeneity from the Triton X-100 extracts of cells of Treponema denticola ATCC 35405 (a human oral spirochete) by a procedure that comprised five successive fast protein liquid chromatography steps. The POPase is a cell-associated 75- to 77-kDa protein with an isoelectric point of ca. 6.5. The enzyme hydrolyzed (optimum pH 6.5) the Pro-pNA bond in carbobenzoxy-Gly-Pro-p-nitroanilide (Z-Gly-Pro-pNA) and bonds at the carboxyl side of proline in several human bioactive peptides, such as bradykinin, substance P, neurotensin, angiotensins, oxytocin, vasopressin, and human endothelin fragment 22-38. The minimum hydrolyzable peptide size was tetrapeptide P3P2P1P'1, while the maximum substrate size was ca. 3 kDa. An imino acid residue in position P1 was absolutely necessary. The hydrolysis of Z-Gly-Pro-pNA was potently inhibited by the following, with the Ki(app) (in micromolar) in parentheses: insulin B-chain (0.7), human endothelin-1 (0.5), neuropeptide Y (1.7), substance P (32.0), T-kinin (4.0), neurotensin (5.0), and bradykinin (16.0). Chemical modification and inhibition studies suggest that the POPase is a serine endopeptidase whose activity depends on the catalytic triad of COOH ... Ser ... His but not on a metal. The amino acid sequence around the putative active-site serine is Gly-Gly-Ser-Asn-Pro-Gly. The enzyme is suggested to contain a reactive cysteinyl residue near the active site. Amino acid residues 4 to 24 of the first 24 N-terminal residues showed a homology of 71% with the POPase precursor from Flavobacterium meningosepticum and considerable homology with the Aeromonas hydrophila POPase. The ready hydrolysis of human bioactive peptides at bonds involving an imino acid residue suggests that enzymes like POPase may contribute to the chronicity of periodontal infections by participating in the peptidolytic processing of those peptides.
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PMID:An endo-acting proline-specific oligopeptidase from Treponema denticola ATCC 35405: evidence of hydrolysis of human bioactive peptides. 752 1

The localisation and colocalisation of neuronal isoform (type I) nitric oxide synthase, endothelin-1, arginine-vasopressin and substance P in endothelial cells of rat coronary and femoral arteries was investigated by pre-embedding and postembedding immunocytochemistry. Nitric oxide synthase appeared in a high proportion of endothelial cells of both arteries (about 89% in the femoral artery, examined with the preembedding avidin-biotin-peroxidase method, and in almost all cells of the coronary artery, examined with the postembedding immunogold technique). Double immunogold labelling in single cells demonstrated the colocalisation of nitric oxide synthase with endothelin-1, arginine-vasopressin and substance P. The immunolabelling was mostly confined to the cytoplasmic matrix. It is suggested that nitric oxide synthase/nitric oxide and the peptides examined may be involved in local control of blood flow in coronary and femoral arteries.
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PMID:Localisation of nitric oxide synthase and its colocalisation with vasoactive peptides in coronary and femoral arteries. An electron microscope study. 752 54

The Wistar fat-storing cells were isolated by perfusion with collagenase and centrifugation with metrizamide density cushion technique and cultured in vitro. The fat-storing cells were confirmed by the presentation of the lipid drop in the cytoplasm and the visualization of dismin with anti-dismin antibody by using indirect immunofluorescence method. By the videotape recorder (VIR) and the imagine analysis system, we observed the wandering immigration, the abrupt contraction of fat-storing cells with spike, then becoming a ball-like shape in its division phase. After that the cell began to extend and the contraction of these cells can be induced by the presence of 10(-2) mmol/L endothelin-1, 1 mmol/L of substance P and 2 x 10(-5) mmol/L noradrenalin. After removal of these agents the contracted cells would become extended. All these findings indicate that the fat-storing cells have ability of contraction and movement.
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PMID:Observations on the contraction and movement of fat-storing cells in culture. 752 80

1. Phosphoramidon, a potent inhibitor of endopeptidase-24.11 (E-24.11) and thermolysin, has been shown to reduce the hypertensive effect of exogenous big endothelin-1 (big ET-1) in rats. To examine whether E-24.11 or thermolysin convert big ET-1 to endothelin-1 (ET-1) and C-terminal fragment (CTF), the effects on porcine and human big ET-1 of each of the purified enzymes were compared in vitro. 2. For E-24.11, the relative rates of hydrolysis were ET-1 > CTF >> big ET-1. The relative half-lives for hydrolysis of 3 nmol of each peptide by 200 ng enzyme were: big ET-1 > 24 h; ET-1, 37 min; CTF, 57 min. For comparison, the half-life for hydrolysis of substance P under similar conditions was 2.1 min. 3. For thermolysin the relative rates of hydrolysis were found to be big ET-1 > CTF > ET-1. The relative half-lives for hydrolysis of 3 nmol peptide by 50 ng enzyme were: big ET-1, 25 min; ET-1, 56 min; CTF, 47 min. 4. Because the low rate of conversion of big ET-1 to ET-1 by E-24.11 did not yield sufficient ET-1 for h.p.l.c. quantification a RIA specific for ET-1(16-21) was used to study further the hydrolysis of big ET-1 by E-24.11. Incubation of big ET-1 (0.2-2 nmol) with E-24.11 (4-400 ng) generated ET-1 levels of between 1.7 and 33 pmol measured by RIA. Incubation of big ET-1 (2 nmol) with E-24.11 (40 ng) for 8 h showed that steady state levels of ET-1 were achieved after 4 h indicating that the rate of ET-1 degradation was then equal to the formation of new ET-1. Characterization of the immunoreactivity by h.p.l.c. and RIA confirmed that authentic ET-1 had been produced, but the yield was insufficient for verification by mass spectrometry.5. Both ET-l-like and CTF-like peaks were detected at 214 nm when the products of big ET-1 hydrolysis by thermolysin were resolved by h.p.l.c. RIA and mass spectrometry confirmed the production of ET-1 with amounts in the range 120-160 pmol.6. The hydrolysis profile of ET-1 by E-24.11 and thermolysin shows that both enzymes have some common cleavage sites consistent with their similar specificities hydrolysing on the amino side of a hydrophobic residue.7. Thermolysin, for which 3D structural information is available, may represent a better model for endothelin converting enzyme (ECE) action than E-24.11 and could be useful for the design of ECE inhibitors. Since E-24.11 can both synthesize and hydrolyse ET-1, the presence of E-24.11 in membrane fractions or in partially purified ECE preparations may produce misleading estimates of ECE activity.
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PMID:Generation by the phosphoramidon-sensitive peptidases, endopeptidase-24.11 and thermolysin, of endothelin-1 and c-terminal fragment from big endothelin-1. 752 8

1. This study investigated tachykinin-evoked vasodilatation in the microvasculature of the hamster cheek pouch in vivo. Arterioles and venules were observed by intravital microscopy with video recording, and vasodilatation and constriction, defined as changes in blood vessel diameter, measured by image analysis. All agents were applied topically by superfusion. None of the agents tested had a significant effect on venule diameter. 2. When arterioles were preconstricted (by ca. 50%) with endothelin-1 present in the superfusing medium, substance P (0.3-30 nM) was a potent vasodilator, being 10 fold more active than both neurokinin A and the NK1 receptor-selective agonist, substance P methyl ester. The NK2 receptor-selective agonist, [beta-Ala8]-NKA(4-10)(0.1-10 microM) was active only at high concentrations, and the NK3 receptor-selective agonist senktide (0.1-10 microM) was virtually inactive (n = 8 hamsters). Dilatation evoked by tachykinins and analogues was rapid in onset (< 0.5 min) and readily reversible. 3. At low concentrations (1-10 nM), the non-peptide tachykinin NK1 receptor antagonist SR140333 ((S)1-(2-[3(3,4-dichlorophenyl)-1-(3-iso-propoxyphenylacetyl)pi peridin-3- yl]ethyl)-4-phenyl-1-azoniabicyclo[2.2.2]octone, chloride) had no effect on the diameter of preconstricted arterioles per se, but potently inhibited dilator responses to substance P methyl ester (apparent pKB 9.9 +/- 0.2; n = 5 hamsters, n = 10 estimates). SR140333 (10 nM) did not inhibit submaximal dilator responses evoked by human alpha calcitonin gene-related peptide (alpha CGRPh; 1.0 nM; P > 0.05; n = 5). 4 The nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10 microM) caused a51.3 +/- 5.4% arteriolar constriction. In the presence of L-NAME, submaximal vasodilator responses to substance P (10-I00 nM) and carbachol (0.1-1.0 microM) were significantly attenuated (n = 5 hamsters;P<0.05) as compared to responses obtained in preparations that were preconstricted to a similar extent by endothelin-l (48.0 +/- 5.6%). L-NAME (10 M) was without effect on submaximal vasodilator responses to alpha CGRPh (0.1 nM) or sodium nitroprusside (1O nM) (n = 5 hamsters; P> 0.05).5 We conclude that tachykinin-evoked arteriolar vasodilatation in the hamster cheek pouch is mediated via NK, receptor activation and depends, at least in part, on the release of nitric oxide. The NKI receptors mediating vasodilatation can be blocked by topical application of SR140333; which may therefore be useful in the investigation of the role of NK1 receptors in neurogenic inflammation in the microvasculature.
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PMID:Inhibition by SR 140333 of NK1 tachykinin receptor-evoked, nitric oxide-dependent vasodilatation in the hamster cheek pouch microvasculature in vivo. 753 May 73

The interaction between endothelial cells and immune/inflammatory cells plays an important role in the pathogenesis of vascular diseases. Inflammatory cells also activate endothelial cells and release both proliferative and cytotoxic mediators. In order to examine the interaction between leukocytes and endothelial cells and the effect of various drugs, we established the methodology for isolating and culturing the endothelial cells from human umbilical vein. Endothelial cells were harvested by using 0.1% collagenase within 48 hr of collecting the cord. Cells were grown to confluency in 96-well plates in Medium 199 containing 20% fetal calf serum, endothelial cell growth supplement, heparin, and antibiotics. Using this method, we obtained a confluent layer of the cells in all the 96 wells within 48 hr. We then examined the effect of peptides, endothelin-1, substance P, and neurokinin-A on the adherence of human blood neutrophils (purity and viability > 98%) to endothelial monolayers. All the peptides enhanced (p < 0.05) the adherence of neutrophils to endothelial cells in a time-dependent manner. This method of endothelial cell culturing is reliable, reproducible, and effective in evaluating the role of various mediators and drugs on the adherence of various white blood cells to endothelium.
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PMID:Technique for assessment of leukocyte adherence to human umbilical vein endothelial cell monolayers. 753 69

This study on the human umbilical artery was undertaken in order to elucidate possible correlations between changes in response to vasoactive substances in vitro and abnormal umbilical artery flow velocity waveforms in vivo associated with preeclampsia and intrauterine growth retardation. The vascular reactivity to endothelin-1, noradrenalin, serotonin, the thromboxane A2 analogue U46619, substance P and prostacyclin was determined in umbilical artery segments from 13 normal pregnancies and 29 pregnancies complicated with preeclampsia and/or intrauterine growth retardation with normal or abnormal umbilical flow velocity waveforms. The contractile effect in vitro of endothelin-1 and noradrenalin was reduced in segments from pregnancies complicated by abnormal umbilical flow velocity waveforms in vivo. No differences were detected in the contractile effect of serotonin and U46619, or in the relaxatory effect of substance P and prostacyclin. In conclusion, endothelin-1- and noradrenalin-related mechanisms could be involved in the abnormal umbilical flow velocity waveforms associated with preeclampsia and intrauterine growth retardation.
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PMID:Reduced contractile effect of endothelin-1 and noradrenalin in human umbilical artery from pregnancies with abnormal umbilical artery flow velocity waveforms. 754 76

The distribution of various vasoactive agents [nitric oxide synthase (NOS)- type I, endothelin-1 (ET-1), arginine-vasopressin (AVP), serotonin (5-HT), histamine and substance P (SP)] in the thoracic aortic endothelium of aged Sprague-Dawley rats was investigated using electron microscopic immunocytochemical methods. The aged thoracic aortic intima was characterized by a large number of leukocytes that adhered to the endothelium, an accumulation of a flake-like precipitate and clusters of leukocytes and smooth muscle cells (SMC) in the subendothelium. Age-associated alterations were also seen in the medial and adventitial layers of the vascular wall. An extensive vasa-vasorum was present in the adventitia from which leukocytes penetrated into perivascular tissue. Some vasa-vasorum showed mast cells adhered to perivascular pericytes. Immunocytochemistry showed about 70% endothelial cells (EC) with positive immunostaining for the brain isoform NOS-type I, compared to 10% in adult mature rats. About 10% of cells showed a positive immunoreaction for ET-1, which is about the same as for the mature adult thoracic aorta (8-9%). Subendothelial macrophages often showed positive immunostaining for antibodies against ET-1. The percentage of EC immunopositive to AVP, 5-HT, and histamine was 16-18, 15 and 12%, respectively compared to 5-8, 7-8 and 6% in mature adult rats. A few cells showed an immunopositive reaction for SP. In summary, the ageing vessel was characterized by a large number of leukocytes adhering to the endothelium and also by the presence of many macrophages and SMC in the subendothelial layer. The percentage of EC in rat thoracic aorta showing NOS immunostaining increased substantially from 10% in mature rats to 70% in aged rats. The percentage of EC immunopositive for AVP, 5-HT and histamine also increased about twofold compared to mature adult rats, while no changes were seen for ET-1.
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PMID:An ultrastructural and immunocytochemical study of thoracic aortic endothelium in aged Sprague-Dawley rats. 758 46

1. This study analyses the receptors mediating the effects of bradykinin (BK) and analogues on neurogenic twitch contractions of the mouse isolated vas deferens evoked, in the presence of captopril (3 microM), by electrical field stimulation with trains of 4 rectangular 0.5 ms pulses of supramaximal strength, delivered at a frequency of 10 Hz every 20 s. 2. BK (0.1-300 nM) induced a graded potentiation of twitches, with an EC50 (geometric mean and 95% confidence limits) of 4.5 nM (1.7-11.6) and an Emax of 315 +/- 19 mg per 10 mg of wet tissue (n = 6). Similar results were obtained in tissues challenged with Lys-BK, [Hyp3]-BK, Met,Lys-BK and the selective B2 receptor agonist [Tyr(Me)8]-BK (0.1-300 nM). 3. The selective B2 receptor antagonists, Hoe 140 (1-10 nM) and NPC 17731 (3-30 nM), caused graded rightward shifts of the curve to BK-induced twitch potentiation, yielding apparent pA2 values of 9.65 +/- 0.09 and 9.08 +/- 0.13, respectively, and Schild plot slopes not different from 1. Both antagonists (100 nM) failed to modify similar twitch potentiations induced by substance P (3 nM) or endothelin-1 (1 nM). Preincubation with the selective B1 receptor antagonist, [Leu8,des-Arg9]-BK (1 microM), increased the potentiating effect of BK on twitches at 30-300 nM. 4. In contrast to BK, the selective B1 receptor agonist, [des-Arg9]-BK (0.3-1000 nM) reduced the amplitude of twitches in a graded fashion, with an IC50 of 13.7 nM (10.4-16.1) and an Imax of 175 +/- 11 mg (n = 4). The twitch depression induced by [des-Arg9]-BK (300 nM) was not affected by Hoe140 (30nM) or NPC 17731 (100nM), but was abolished by the selective B1 receptor antagonist,[Leu8,des-Arg9]-BK (1 microM), which did not modify the twitch inhibitory effect of clonidine (1 nM) or morphine (300 nM).5. In non-stimulated preparations, BK (100 nM) also potentiated, in a Hoe 140-sensitive (10 nM)manner, the contractions induced by ATP (100 microM), but not by noradrenaline (10 microM), whereas[des-Arg9]-BK (300 nM) did not modify the contractions induced by either agonist.6. It is concluded that the mouse vas deferens expresses both B1 and B2 receptors, which modulate sympathetic neurotransmission in opposing ways. Neurogenic contractions are inhibited by stimulation of possibly prejunctional B, receptors, whereas activation of B2 receptors increases twitch contractions,in part by amplifying the responsiveness of the smooth muscle cells to the sympathetic co-transmitter ATP.
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PMID:Characterization of kinin receptors modulating neurogenic contractions of the mouse isolated vas deferens. 760 50


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