Receptor-independent metabolism of platelet-activating factor by myelogenous cells

FEBS Lett. 1989 Jul 3;250(2):341-4. doi: 10.1016/0014-5793(89)80751-3.

Abstract

Human neutrophils incorporate and metabolize platelet-activating factor (PAF). We dissociated these events from PAF binding to its receptors. Cells were pretreated with either pronase, a PAF antagonist (L652731), or excess PAF. This reduced PAF receptor numbers by 70 to almost 100% but had no comparable effect upon the neutrophil's ability to metabolize PAF. Furthermore, HL-60 cells efficiently metabolized, but did not specifically bind, PAF. Thus, PAF receptor availability did not correlate with PAF metabolic capacity and we conclude that myelogenous tissues can process this bioactive ligand by a receptor-independent pathway.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Humans
  • Neutrophils / metabolism
  • Platelet Activating Factor / metabolism*
  • Platelet Membrane Glycoproteins*
  • Receptors, Cell Surface / metabolism*
  • Receptors, G-Protein-Coupled*
  • Tumor Cells, Cultured

Substances

  • Platelet Activating Factor
  • Platelet Membrane Glycoproteins
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • platelet activating factor receptor