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)

Vasoactive peptides contain a high proportion of proline residues which make them resistant to hydrolysis by many peptidases. However, post proline cleaving enzyme (PPCE; EC 3.4.21.26), a proline specific endopeptidase which specifically hydrolyzes internal peptide bonds on the carboxyl side of proline residues, has been shown to inactivate numerous vasoactive peptides including angiotensins, kinins, substance P, vasopressin and oxytocin. In order to determine whether PPCE could be involved in vascular metabolism of vasoactive peptides, we carried out localization and characterization studies of PPCE-like activity in hog aorta and mesenteric artery. PPCE was assayed fluorometrically at pH 7.0 using the specific PPCE substrate CBZ-Gly-Pro-4-methyl-coumarinylamide. The subcellular distribution of vascular PPCE was essentially the same as that of the cytosolic marker enzyme lactic dehydrogenase (LDH). PPCE was enriched six-fold in the cytosolic fraction (11.4 +/- 2.7 units/mg) and unlike the plasma membrane-bound proline specific exopeptidase dipeptidyl-(amino)peptidase IV (DAP IV; EC 3.4.14.5), little or no activity could be detected in the microsomal or plasma membrane fractions. Similar to PPCE characterized from other sites, vascular PPCE was stabilized and activated by dithiothreitol and EDTA, and inhibited by DFP, p-chloromercuriphenyl sulfonic acid, L-1-tosylamido-2-phenylethylchloromethyl ketone, Cu++, Ca++, and Zn++. Vascular PPCE was unaffected by inhibitors of trypsin and kallikrein (Aprotinin, ABTI), aminopeptidase M (bestatin, amastatin), neutral endopeptidase (phosphoramidon), angiotensin I converting enzyme (captopril) or carboxypeptidase N (MERGETPA). These data demonstrate that PPCE is present in vascular endothelium and/or smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Vascular, post proline cleaving enzyme: metabolism of vasoactive peptides. 354 18

A specific and sensitive radioimmunoassay of human vasoactive intestinal polypeptide using synthetic VIP as standard preparation and antiserum to synthetic VIP R 502 (Yanaihara et al. 15) is described. No crossreactions with a number of other gastrointestinal hormones such as glucagon, secretin, GIP, HPP or substance P was detected. Aprotinin (Trasylol, Bayer) or heparin had no influence on the antigen--antibody reaction. High concentrations of sodium or potassium chloride in plasma, or hyperlipoproteinemia, did not interfere with the antiserum in the described system. Basal plasma concentration of VIP in 18 females (means +/- sem = 24.05 +/- 1.79 VIP/l) and 20 males (means +/- sem = 24.11 +/- 1.91 pmol/l VIP) showed no sex specific variations. During gastroscopy plasma VIP levels were significantly higher than basal values, showing a peak secretion when the gastric antrum was inspected. During the entire colonoscopic examination, VIP levels were significantly higher than basal values. Endoscopic examination may possibly liberate VIP from the VIP containing cells which can be found throughout the gastrointestinal tract.
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PMID:Radioimmunoassay for vasoactive intestinal polypeptide (VIP) in plasma before and during endoscopic examinations. 712 38

1. The effect of topical betamethasone upon skin blood flow was investigated in the rat. Two types of vasodilator stimuli were used; local heating to the surface of the skin and intradermal application of inflammatory agents. Blood flow was measured by laser doppler velocimetry. 2. Topical betamethasone-17-valerate (1 g with an 18 h pretreatment) significantly inhibited the heat-induced vasodilatation in the rat skin, as also did systemically administered betamethasone (1 mg kg-1, 3 h pretreatment). 3. Angiotensin converting enzyme (ACE) inhibitors (captopril, 5 mg kg-1 and enalapril, 1 mg kg-1, 30 min pretreatments) were the only drugs out of several different types of systemically administered inhibitors and antagonists that were tested which also inhibited the heat-induced vasodilatation. Aprotinin (100,000 KIU kg-1, 5 min pretreatment) a serine protease inhibitor, significantly potentiated the heat-induced response. 4. Bradykinin (50 nmol per site), des-Arg9-bradykinin (5 nmol per site), substance P (0.1 nmol per site) and capsaicin (1 mumol per site) induced an increase in skin blood flow. 5. Topical betamethasone treatment resulted in a significant inhibition of the vasodilator response to des-Arg9-bradykinin, whereas captopril treatment inhibited the responses to substance P, capsaicin, bradykinin and des-Arg9-bradykinin. 6. Intradermal application of captopril (10-100 micrograms) also caused a dose-dependent inhibition of the heat-induced vasodilatation. 7. These results suggest that topical betamethasone may be acting in a manner similar to that of the ACE inhibitors to produce an inhibition of the flow responses in the skin and that this effect may be brought about by interfering with the action of vasodilator peptide(s) or protein(s).
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PMID:Investigations into the mechanism of vasoconstrictor action of the topical steroid betamethasone-17-valerate in the rat. 844 1

Calcitonin gene-related peptide (CGRP) released from sensory neurons, which are closely apposed to mast cells and blood vessels, mediates gastric hyperemia in response to acid challenge of the damaged mucosa. Substance P (SP) is coreleased with CGRP from sensory neurons, but the role of this peptide in gastric blood flow regulation is largely unknown. Chambered rat stomachs were exposed to 1.5 M NaCl and acidic saline after treatment with SP, aprotinin (serine protease inhibitor), and the mast cell stabilizers ketotifen and sodium cromoglycate (SCG). Gastric hyperemia (measured with a laser Doppler flow velocimeter) after hypertonic injury and acid challenge was nearly abolished by SP. Aprotinin infused together with SP and pretreatment with ketotifen and SCG before SP restored the gastric hyperemia. Ketotifen and SCG inhibited mast cell degranulation in SP-treated rats. Preservation of gastric hyperemia was correlated with improved mucosal repair. These data suggest that impaired hyperemia by SP during acid challenge of the gastric mucosa may be mediated by a mast cell-dependent mechanism involving the release of proteases from mast cells.
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PMID:Substance P may attenuate gastric hyperemia by a mast cell-dependent mechanism in the damaged gastric mucosa. 1056 13