Pharmacological characterization of the Raji lymphoblast platelet-activating factor receptor

Jeffrey Travers, Q. Li, R. H. Fertel

Research output: Contribution to journalArticle

Abstract

Previous studies in our laboratory have described the presence of high-affinity platelet-activating factor (PAF) binding sites on the B lymphoblast cell line, Raji. In the present study, PAF receptor antagonists were used to examine the specificity of [3H]PAF binding and PAF-induced intracellular calcium mobilization in this human lymphocyte cell line. In binding studies conducted at 4°C, PAF receptor antagonists competed with [3H]PAF for binding to Raji lymphocytes with the following rank order of potency: Ro 19-3704 ~ CV-6209 > CV-3988 > BN52021 > alprazolam. This order of potency is similar to those described for binding studies in platelets and neutrophils. The PAF receptor antagonists CV-6209 and alprazolam inhibited the PAF-induced calcium changes and PAF binding with similar potencies, indicating that the high-affinity PAF binding sites are functional receptors coupled to calcium mobilization. The calcium channel antagonists verapamil, diltiazem, and nimodipine inhibited Raji lymphoblast PAF binding with similar potencies, but had no effect on PAF-induced intracellular calcium changes, suggesting the possibility that these compounds are not true competitive antagonists. These studies provide evidence that the Raji lymphoblast PAF receptor is pharmacologically similar to PAF receptors found on platelets and neutrophils, and thus could be of use as a model system to study the PAF receptor.

Original languageEnglish (US)
Pages (from-to)365-374
Number of pages10
JournalDrug Development Research
Volume24
Issue number4
StatePublished - 1991
Externally publishedYes

Fingerprint

Platelet Activating Factor
Pharmacology
Alprazolam
Calcium
Lymphocytes
Platelets
Neutrophils
Blood Platelets
Binding Sites
Cells
platelet activating factor receptor
Cell Line
Nimodipine
Diltiazem
Calcium Channel Blockers
Verapamil

Keywords

  • Calcium channel antagonist
  • Lymphocyte
  • PAF receptor

ASJC Scopus subject areas

  • Organic Chemistry
  • Drug Discovery
  • Pharmacology

Cite this

Pharmacological characterization of the Raji lymphoblast platelet-activating factor receptor. / Travers, Jeffrey; Li, Q.; Fertel, R. H.

In: Drug Development Research, Vol. 24, No. 4, 1991, p. 365-374.

Research output: Contribution to journalArticle

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