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)

The airways of the guinea pig are innervated by four types of autonomic nerves: cholinergic excitatory, adrenergic inhibitory, nonadrenergic noncholinergic (NANC) excitatory, and NANC inhibitory. Tachykinins (neurokinins A and B and substance P) are believed to mediate NANC excitatory responses, and vasoactive intestinal peptide (VIP) has been proposed as the chemical mediator of the NANC inhibitory system. Enzymatic degradation represents an important means by which the biologic actions of neurotransmitters are terminated. In the present study, relaxation responses of guinea pig tracheae to NANC nerve stimulation and to exogenous VIP administration were compared in the absence and presence of various peptidase inhibitors. NANC inhibitory responses elicited by electrical field stimulation were unaffected by aprotinin or soybean trypsin inhibitor but were depressed by thiorphan or leupeptin. Concentration-response curves to exogenous VIP were shifted to the left by soybean trypsin inhibitor but were not affected by aprotinin, leupeptin, or thiorphan. After tachykinin depletion with capsaicin, thiorphan also induced a leftward shift in the VIP concentration-response curve. Under the same conditions, thiorphan failed to influence NANC inhibitory responses. These results indicate that the NANC inhibitory neurotransmitter is not metabolized by enzymes susceptible to inhibition by aprotinin, leupeptin, soybean trypsin inhibitor, or thiorphan and, accordingly, distinguish NANC nervous responses from those induced by VIP. The results also suggest that the NANC excitatory system can interact functionally with the NANC inhibitory system, as evidenced by the blunting of NANC relaxation responses following inhibition of tachykinin metabolism and elimination of this effect by capsaicin.
 ...
PMID:Enzymatic modulation of vasoactive intestinal peptide and nonadrenergic noncholinergic inhibitory responses in guinea pig tracheae. 224 Aug 34

The regulatory mechanism of the pulpal microcirculatory hemodynamics was investigated by measuring pulpal blood flow (PBF) in dogs by means of a laser doppler flowmeter. Application of vasodilators (acetylcholine, isoproterenol, histamine, bradykinin and substance P) to the prepared cavity caused an increase in PBF, and norepinephrine reduced PBF. These vasoactive substance-induced responses, but not the bradykinin-induced response, were inhibited by i.v. injection of antagonists (atropine, propranolol, diphenhydramine and [D-Pro2, D-Trp7,9]-substance P). The effect of bradykinin was inhibited by indomethacin, but not by des-Arg9-[Leu8]-bradykinin. Furthermore, prostaglandin E2 produced a concentration-dependent increase in PBF. These results suggest that acetylcholine, histamine, bradykinin, substance P and norepinephrine, if present, influence the local vasomotor regulation in the dental pulp, and that bradykinin may exert the effect via prostaglandin synthesis. Based on this suggestion, the effect of electrical stimulation of the distal end of the cut inferior alveolar nerve on PBF was studied. The nerve stimulation-induced increase in PBF was inhibited by indomethacin, but not by atropine, propranolol, diphenhydramine, soybean trypsin inhibitor, aprotinin, des-Arg9-[Leu8]-bradykinin, or by [D-Pro2, D-Trp7,9]-substance P. The experiments show that the increase in PBF produced by stimulation of the inferior alveolar nerve is not mediated by common efferent vasodilatory mechanisms, and it is probably mediated by prostaglandin release via the sensory nerve axon reflex mechanism.
 ...
PMID:[Effect of vasoactive substances and electrical stimulation of the inferior alveolar nerve on blood flow in the dental pulp in dogs]. 322 99

Cultured bovine pulmonary artery endothelial cells contain a second peptidyl dipeptidase, distinct from angiotensin-converting enzyme, present in an inactive form associated with a non-dialyzable inhibitor. Partial purification by glycine affinity chromatography separates enzyme from inhibitor to yield a preparation which hydrolyzes angiotensin-1, bradykinin, substance P, atriopeptin-2, enkephalin and Hip-His-Leu. This enzyme is resistant to inhibition by lisinopril, captopril, thiorphan, phosphoramidon, soybean trypsin inhibitor, PMSF and aminopeptidase and carboxypeptidase inhibitors, but is inhibited by EDTA.
 ...
PMID:Conversion of angiotensin-1 to angiotensin-2 by a latent endothelial cell peptidyl dipeptidase that is not angiotensin-converting enzyme. 351 10

By acid extraction, ethanol precipitation, affinity chromatography on 4-phenylbutylamine-Sepharose 4B and gel filtration on Sephadex G-100, calf liver neutral proteinase was purified. The purified enzyme was electrophoretically homogeneous and over 2000 times more active than the starting homogenate. The molecular weight, determined by SDS electrophoresis, was calculated as 27000. The pH optimum of the enzyme for whole calf thymus histones and N-benzoyltyrosine, ethyl ester (BTEE) was at 7.0 and 7.0-7.5. The Km value for histones was 2% and for BTEE 1.66 mM. The enzyme was strongly inhibited by soya-bean trypsin inhibitor and leucocyte intracellular I-1A inhibitor and less by alpha 1-antitrypsin and leucocyte inhibitor I-1B. The enzyme hydrolyzed only selected protein substrates, such as total thymus histones, Lys-rich histones, nucleoprotein and substance P, but not Arg-rich histones, hemoglobin and casein. The enzyme showed chymotrypsin-like properties by cleavage of substance P at the carboxyl groups of phenylalanine and leucine.
 ...
PMID:The isolation of liver serine proteinase by affinity chromatography on 4-phenylbutylamine-sepharose 4 B. 705 3

Serine proteinases participate in many inflammatory events in the airway. We therefore screened perfusates of isolated rat tracheas for tryptic, elastolytic, and chymotryptic serine proteinases. Only chymotryptic activity, indicated by hydrolysis of the synthetic substrate N-succinylalanylalanylprolylphenylalanyl p-nitroaniline (AAPF), was consistently detected in these perfusates. Basal levels of chymotryptic activity were not increased significantly by electrical field stimulation (EFS) (mean change +/- SEM: -0.05 +/- 0.05 m o.d. units, n = 4) or by 10(-7) M substance P (SP) (+0.04 +/- 0.02 m o.d. units, n = 14). However, the mean change after the stimuli were jointly administered (0.17 +/- 0.06 m o.d. units, n = 12) was significantly greater than control or after EFS (P = 0.01, one-way ANOVA). The SP + EFS-induced chymotryptic activity was inhibited by PMSF, soybean trypsin inhibitor, and chymostatin and was associated with an increase in histamine concentration and immunoreactivity to rat mast cell proteases (RMCP), indicating that the activity is due to mast cell degranulation. However, the activity was not significantly decreased by pretreating rats with systemic compound 48/80. SP + EFS-induced chymotryptic activity peaked rapidly and was associated with modest histamine release and an immediate peak in immunoreactivity to RMCP II, a marker of mucosal mast cells. Immunoreactivity to RMCP I, a marker of connective tissue mast cells, also increased after SP + EFS, but this immunoreactivity was either delayed or more sustained and did not coincide with the peak of chymotryptic activity.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Chymotryptic activity in perfusates of isolated rat trachea: correlation with mucosal and connective tissue mast cell secretion. 752 16

A chymostatin-sensitive angiotensin II-generating enzyme was found in human gastroepiploic arteries. The enzyme was purified using heparin affinity and gel filtration columns. The molecular mass of the purified enzyme was 30 kDa, and the optimum pH was between 7.5 and 9.0. Enzyme activity was inhibited by soybean trypsin inhibitor, phenylmethylsulfonyl fluoride and chymostatin, but not by ethylenediaminetetraacetic acid, pepstatin and aprotinin. The enzyme rapidly converted angiotensin I to angiotensin II (K(m), 67 mumol/l; Vmax, 43 pmol/s, kcat, 65/s), but did not hydrolyse angiotensin II, substance P, bradykinin, vasoactive intestinal peptide, luteinizing hormone-releasing hormone, somatostatin and alpha-melanocyte-stimulating hormone. The N-terminal sequence was identical to the sequence for human skin/heart chymase. Thus, the chymostatin-sensitive angiotensin II-generating enzyme in human vascular tissues is identified as chymase.
 ...
PMID:Characterization of chymase from human vascular tissues. 935 25