Endothelial Alterations During The Platelet Activating Factor (PAF) Respiratory Distress Syndrome
Year: 1981
Type: conference-paper
Abstract: PAF (l-0-alkyl-2-0-acetyl-sn-gylcero-3-phosphocholine) induces polymorphonucelar leukocyte and platelet stasis in rabbit lung capillaries in vitro and produces a model of acute respiratory disease. Since PAF mediates anaphylactic reactions, a study was done to determine the ultrastructural effects of PAF treatment. Mature rabbits were treated by intravenous administration of either PAF (0.15-10 μg/kg: 8 animals) or BSA (the PAF carrier: 3 animals) prior to sacrifice and intraventricular perfusion with 0.1 M phosphate buffered (pH 7.2) glutaraldehyde (2.5%). Animals (n=5) injected with a high concentration of PAF (3-10 μg/kg) and sacrificed within 15 minutes of PAF administration had grossly contracted lungs, the vasculature of which (as observed by scanning electron microscopy) contained numerous marginated leukocytes and platelet aggregates. Animals (n=3) given PAF in the concentration range 0.15-2.4 μg/kg had less consistent lung contraction and fewer platelet aggregates within capillaries. Luminal surfaces of capillary endothelial cells in all PAF treated animals (when observed by transmission electron microscopy [TEM]) were dramatically altered. In contrast to the uniformly smooth surfaces in control animals, vessels in the PAF treated animals had tortuous surfaces with plasma membrane discontinuities and protrusion of plasma membrane fragments into the capillary lumen. Morphometric analysis of TEM micrographs substantiated statistically significant (p<0.01) increases in the number and size of plasmalemmal vesicles. These observations clearly document a cytotoxic effect for capillary endothelium. This cytotoxic action may in part explain the clinical effect of PAF.
Source: Thrombosis and Haemostasis
Authors: J C Lewis, J T O’Flaherty, C M McCall, R L Wykle
Institution: Atrium Health Wake Forest Baptist
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2882992108