CV 6209 is a non-competitive antagonist of platelet-activating factor receptors on guinea-pig resident peritoneal macrophages

Abstract

1. The characteristics of antagonism of platelet-activating factor (Paf) receptors by the phospholipid Paf analogue, CV 6209, were studied in rabbit platelets and polymorphonuclear leucocytes (PMN) and in guinea-pig macrophages. 2. Paf-induced aggregation of PMN or platelets was antagonized in a competitive and specific manner by CV 6209 with no detectable difference between the pA2 values (approximately 9.5). 3. The specificity of CV 6209 (1-100 nmol/L) for Paf receptors in platelets and PMN was indicated by a lack of effect on A23187 (10 μmol/L) or fMLP (1 μmol/L) induced aggregation, respectively. 4. CV 6209 (1-100 nmol/L) was also a potent antagonist of Paf-induced prostacyclin (PGI2) ge..