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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2001-5-8
pubmed:abstractText
The anaphylatoxin C3a is a potent chemotactic peptide and inflammatory mediator released during complement activation which binds to and activates a G-protein-coupled receptor. Molecular cloning of the C3aR has facilitated studies to identify nonpeptide antagonists of the C3aR. A chemical lead that selectively inhibited the C3aR in a high throughput screen was identified and chemically optimized. The resulting antagonist, N(2)-[(2,2-diphenylethoxy)acetyl]-L-arginine (SB 290157), functioned as a competitive antagonist of (125)I-C3a radioligand binding to rat basophilic leukemia (RBL)-2H3 cells expressing the human C3aR (RBL-C3aR), with an IC(50) of 200 nM. SB 290157 was a functional antagonist, blocking C3a-induced C3aR internalization in a concentration-dependent manner and C3a-induced Ca(2+) mobilization in RBL-C3aR cells and human neutrophils with IC(50)s of 27.7 and 28 nM, respectively. SB 290157 was selective for the C3aR in that it did not antagonize the C5aR or six other chemotactic G protein-coupled receptors. Functional antagonism was not solely limited to the human C3aR; SB 290157 also inhibited C3a-induced Ca(2+) mobilization of RBL-2H3 cells expressing the mouse and guinea pig C3aRS: It potently inhibited C3a-mediated ATP release from guinea pig platelets and inhibited C3a-induced potentiation of the contractile response to field stimulation of perfused rat caudal artery. Furthermore, in animal models, SB 290157, inhibited neutrophil recruitment in a guinea pig LPS-induced airway neutrophilia model and decreased paw edema in a rat adjuvant-induced arthritis model. This selective antagonist may be useful to define the physiological and pathophysiological roles of the C3aR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
166
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6341-8
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed-meshheading:11342658-Animals, pubmed-meshheading:11342658-Anti-Inflammatory Agents, Non-Steroidal, pubmed-meshheading:11342658-Arginine, pubmed-meshheading:11342658-Arthritis, Experimental, pubmed-meshheading:11342658-Benzhydryl Compounds, pubmed-meshheading:11342658-Binding, Competitive, pubmed-meshheading:11342658-Cell Line, pubmed-meshheading:11342658-Complement C3a, pubmed-meshheading:11342658-Complement Inactivator Proteins, pubmed-meshheading:11342658-Disease Models, Animal, pubmed-meshheading:11342658-Edema, pubmed-meshheading:11342658-Guinea Pigs, pubmed-meshheading:11342658-Hindlimb, pubmed-meshheading:11342658-Humans, pubmed-meshheading:11342658-Injections, Intraperitoneal, pubmed-meshheading:11342658-Leukocytosis, pubmed-meshheading:11342658-Male, pubmed-meshheading:11342658-Membrane Proteins, pubmed-meshheading:11342658-Mice, pubmed-meshheading:11342658-Muscle Contraction, pubmed-meshheading:11342658-Neutrophil Infiltration, pubmed-meshheading:11342658-Rats, pubmed-meshheading:11342658-Rats, Inbred Lew, pubmed-meshheading:11342658-Rats, Sprague-Dawley, pubmed-meshheading:11342658-Receptors, Complement, pubmed-meshheading:11342658-Tumor Cells, Cultured
pubmed:year
2001
pubmed:articleTitle
Identification of a selective nonpeptide antagonist of the anaphylatoxin C3a receptor that demonstrates antiinflammatory activity in animal models.
pubmed:affiliation
Department of Molecular Biology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406-0939, USA. bob_ames-1@sbphrd.com
pubmed:publicationType
Journal Article