Linked Life Data

1697312

Source:http://linkedlifedata.com/resource/pubmed/id/1697312

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1990-10-3
pubmed:abstractText
Incubation of radiolabeled human C3a with rat peritoneal mast cells resulted in high levels of uptake and extensive degradation of the ligand. Both cell-bound and free radiolabeled human C3a underwent extensive degradation by rat mast cells even at 0 degrees C. We examined several protease inhibitors for their ability to prevent degradation of radiolabeled human C3a by the rat mast cells. The inhibitors PMSF, chymostatin, and soybean trypsin inhibitor were most effective in preventing radiolabeled human C3a degradation. Degradation of the cell-bound ligand was totally inhibited only by PMSF. These compounds are effective inhibitors of a chymotrypsin-like enzyme (chymase) extracted from rat mast cells. Chemical cross-linking of radiolabeled human C3a to surface components on the rat mast cells, in the presence of PMSF, revealed one major and two minor bands. The mast cell component in both the major and minor bands proved to be chymase-associated based on a direct comparison with purified chymase isolated from rat mast cells. However, neither antichymase antibody nor chymase inhibitors influenced the degranulating activity of C3a on rat mast cells that occur independently of the C3a-chymase interactions. We conclude that there are neither specific C3a-binding sites on rat mast cells nor specific receptors whose occupancy leads to cellular activation. Although human C3ades Arg is inactive on guinea pig ileal and lung tissue, it binds to and induces degranulation of rat mast cells, as well as enhances vascular permeability in rat skin, at concentrations nearly identical to that of intact C3a. The fact that both C3a and C3ades Arg stimulated mast cell activation, at concentrations in excess of 10(-6) M, argues against specific binding sites for the anaphylatoxin on rat mast cells. It is proposed that the cationic C3a molecule activates rat mast cells in a secretory and nonlytic manner by a nonspecific mechanism similar to that of other polybasic compounds.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
145
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1851-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:1697312-Anaphylatoxins, pubmed-meshheading:1697312-Animals, pubmed-meshheading:1697312-Capillary Permeability, pubmed-meshheading:1697312-Cell Degranulation, pubmed-meshheading:1697312-Cell Membrane, pubmed-meshheading:1697312-Cross-Linking Reagents, pubmed-meshheading:1697312-Endocytosis, pubmed-meshheading:1697312-Glucuronidase, pubmed-meshheading:1697312-Histamine Release, pubmed-meshheading:1697312-Humans, pubmed-meshheading:1697312-Macrophage-1 Antigen, pubmed-meshheading:1697312-Mast Cells, pubmed-meshheading:1697312-Peritoneal Cavity, pubmed-meshheading:1697312-Protease Inhibitors, pubmed-meshheading:1697312-Rats, pubmed-meshheading:1697312-Receptors, Complement, pubmed-meshheading:1697312-Skin, pubmed-meshheading:1697312-Species Specificity, pubmed-meshheading:1697312-Structure-Activity Relationship, pubmed-meshheading:1697312-Time Factors
pubmed:year
1990
pubmed:articleTitle
Anaphylatoxin binding and degradation by rat peritoneal mast cells. Mechanisms of degranulation and control.
pubmed:affiliation
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, CA 92037.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.