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PAF-releasing factor in human serum and inflammatory exudate

Y Okamoto1, H Yoshida, M Ino

  • 1Department of Biochemistry, School of Pharmaceutical Science, University of Shizuoka, Japan.

Journal of Lipid Mediators
|November 1, 1993
PubMed

Insights

A novel PAF-releasing factor found in inflammatory exudate acts as a carrier for platelet-activating factor (PAF) in blood and during inflammation.

Area of Science:

  • Immunology
  • Biochemistry

Background:

  • Platelet-activating factor (PAF) plays a crucial role in inflammatory responses.
  • A PAF-releasing factor was previously identified in human serum.

Purpose of the Study:

  • To confirm the presence of PAF-releasing factor in inflammatory exudate.
  • To characterize the properties and function of this PAF-releasing factor.

Main Methods:

  • Detection and partial purification of PAF-releasing factor from human serum and inflammatory exudate.
  • Assays to determine the binding affinity of the factor for PAF and other lipids.
  • Platelet aggregation studies using PAF bound to the factor.
  • Hydrolysis resistance assays using PAF acetylhydrolase.

Main Results:

  • PAF-releasing factor was confirmed in inflammatory exudate.
  • The factor exhibited higher affinity for PAF compared to triacylglycerol, cholesterol ester, fatty acid, or phosphatidylcholine.
  • PAF bound to the factor induced platelet aggregation similarly to BSA-bound PAF.
  • The PAF-factor complex was resistant to hydrolysis by PAF acetylhydrolase.

Conclusions:

  • The PAF-releasing factor identified in human serum is also present in inflammatory exudate.
  • This factor functions as a carrier for PAF in both blood circulation and inflammatory processes.
  • Its resistance to hydrolysis suggests a role in stabilizing PAF during inflammation.

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