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)

1. The 86Rb release response in the parotid due to alpha-adrenergic (epinephrine), muscarinic (carbachol) or peptide (Substance P) receptor activation exhibited 'fade': a return of efflux to control levels despite the continuing presence of agonist. 2. The time course of fade of the response to all three agonists was independent of the concentration of the agonist. 3. After fade was fully developed to one agonist, the response to an agonist acting on a different receptor was either absent or greatly diminished. 4. Removal of carbachol from muscarinic receptors with atropine 10 min prior to Substance P partially restored the ability of Substance P to produce a response. 5. Fade of the response with all three agonists was greatly retarded by the omission of Ca. 6. release of alpha-amylase did not appear to fade following exposure to carbachol or Substance P. 7. It is concluded that the K+ release response may be inactivated with time due to diminution in responsiveness of the K+ channel to an increase in internal Ca2+.
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PMID:Role of calcium in the fade of the potassium release response in the rat parotid gland. 21 55

1. A modified continuous assay of alpha-amylase is detailed and its usefulness in measuring amylase secretion from rat parotid salivary gland described. 2. The alpha-amylase secretion from the rat parotid gland can be evoked by acetylcholine, substance P and isoprenaline. 3. The secretion of amylase was greatest following isoprenaline stimulation and was of a slower time course than with the other two agonists.
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PMID:Description of an automated assay for measurement of alpha-amylase in vitro from rat parotid gland slices. 244 21

Substance P, forskolin and isoprenaline stimulated rat parotid alpha-amylase secretion in vitro. Synergistic responses were observed with combinations of any two of the three secretagogues such that subthreshold doses of one caused a pronounced shift in the dose-response curve to the second. This potentiation of secretion could neither be explained by an interaction at the receptor recognition binding site, as identified by ligand binding, nor wholly by interactions in second messenger systems. Thus forskolin and isoprenaline were unable to alter substance P-induced changes in phosphatidylinositol metabolism. Similarly substance P was without effect on forskolin or isoprenaline-stimulated cAMP production. In contrast the potentiation of isoprenaline-induced amylase secretion by forskolin was preceded by a marked enhancement of cAMP production suggesting that the activation of the adenylate cyclase complex is reflected in the cellular response.
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PMID:Synergistic interactions between forskolin, isoprenaline and substance P as secretagogues in rat parotid glands. 245 34

A modified fluorescence assay for alpha-amylase activity is described. The method employs amylopectin anthranilate as substrate and offers the advantages of economy of time and resources over a previously described technique using the same substrate. The sample containing alpha-amylase is incubated with the substrate for 5 min at 30 degree C in a final volume of 750 microliter. The fluorescent products of the reaction are separated from the substrate by the addition of methanol, and the methanol-soluble fluorescence is measured in a fluorescence spectrometer. A highly reproducible linear relationship between fluorescence and alpha-amylase activity is obtained for enzyme activities up to 2 units. The absolute sensitivity of the assay under these conditions was estimated to be 0.02 EU (= 0.08 EU ml-1). The application of the assay method to a study of the effects of isoprenaline and substance P-like peptides on the release of alpha-amylase from rat parotid gland slices is described. The assay is particularly suitable for studies on agonists, such as substance P, which have a low ceiling effect in terms of amylase release.
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PMID:A modified amylase assay, using a fluorescent substrate, and its application to a study of the rat parotid gland in vitro. 617 29

The relative potencies of a series of substance P analogues have been determined for spasmogenic activity in the guinea-pig ileum in vitro and for the release of 86Rb and alpha-amylase activity from rat parotid gland slices in vitro. Equipotent molar ratios (EMR), relative to substance P, were determined for all the compounds. In the rat parotid gland, EC50 values for amylase release were, on average, 35.5 times greater than those for 86Rb release. Analysis of Hill plots suggests that spare receptors exist for 86Rb release but not for amylase release and it is suggested that the stimulus-response coupling for amylase release may be less efficient than that for 86Rb release. In the parotid gland, the octapeptide and [less than Glu6]-hexapeptide C-terminal fragments of substance P were less active than substance P itself, whereas in the ileum, the octapeptide was as active as substance P. Substitutions at the Phe7 or Phe8 positions in general reduced activity relative to substance P. This effect was particularly apparent in C-terminal hexapeptide analogues. Substitutions at the Phe7 and Phe8 positions in C-terminal hexapeptide analogues produced a greater reduction in activity in the parotid gland than in the ileum. The most marked difference was observed with eledoisin-related peptide for which the ratio of EMRs for ileum and 86Rb release was 18.1. The unsubstituted C-terminal octapeptide fragment similarly showed a discrepancy between the two assay systems (EMR ratio, ileum: 86Rb release = 7.75). It is suggested that the results may indicate the presence of sub-populations of 'substance P receptors' which are represented at least in different proportions in the two tissues studied, although alternative explanations such as differences in metabolism of agonists are possible.
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PMID:Relative activities of substance P-related peptides in the guinea-pig ileum and rat parotid gland, in vitro. 619 40

Psychosocial stress has been shown to induce inflammatory reactions, followed by the release of immunosuppressive glucocorticoids. This may be mediated by catecholamines or other stress reactive substances such as neuropeptides or cytokines. We here set out to explore the effects of acute psychosocial stress on plasma levels of substance P (SP), a possible mediator of stress-induced inflammatory reactions, and interleukin-1 receptor antagonist (IL-1ra). Twelve healthy male subjects (mean age 27 yrs.) were subjected to the psychosocial stress test "Trier Social Stress Test" (TSST) and a resting control condition. Blood and saliva samples were taken before, as well as 1, 20, 45, and 90 min after TSST or rest, respectively. Salivary cortisol and plasma SP and IL-1ra were measured using immunoassays, salivary alpha-amylase (sAA) was measured by an enzyme kinetic method, and plasma epinephrine (E) and norepinephrine (NE) were measured by HPLC. The TSST induced immediate increases of E, NE, and sAA, and a delayed increase of free cortisol. Plasma IL-1ra showed an even further delayed peak at 90 min after stress. Plasma levels of SP did not respond to stress. No significant associations between changes of stress hormones and IL-1ra or SP were found. We conclude that substance P, epinephrine, and norepinephrine are probably not involved in mediating peripheral inflammation following psychosocial stress, at least with respect to IL-1ra. Further studies have to reveal the mechanisms involved in the stress-induced up regulation of IL-1ra.
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PMID:No response of plasma substance P, but delayed increase of interleukin-1 receptor antagonist to acute psychosocial stress. 1641 81