title: Structure-activity relationships for platelet-activating factor (PAF) and analogues reveal differences between PAF receptors on platelets and macrophages.
abstract: Analogues of PAF were examined for their potency in stimulating either platelet aggregation or macrophage superoxide anion generation. Modification of either the alkyl side-chain or the acetyl side-chain increased the relative potency of PAF analogues in macrophages, but all these compounds were more active in platelets. However, an analogue of PAF with an increased inter-ionic distance in the polar head group, hexanolamine PAF, showed a greater potency in macrophages than platelets. The latter compound also appeared to act as a partial agonist in both rabbit platelets and guinea-pig macrophages, but not in guinea-pig platelets. Differences in the rank order of potency of the PAF analogues in stimulating these cell elements suggest that platelet and macrophage PAF receptors differ.
authors.affiliation: Department of Physiology, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: A G
authors.initials: AG
authors.lastname: Stewart
authors.forename: G
authors.initials: G
authors.lastname: Grigoriadis
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D006168:Guinea Pigs; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D010972:Platelet Activating Factor / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D010974:Platelet Aggregation; D010980:Platelet Membrane Glycoproteins; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled; D013329:Structure-Activity Relationship; D013481:Superoxides / Q000378:metabolism
chemical_list: D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D013481:Superoxides