Platelet-activating factor stimulates lung pericyte growth in
-vitro.
Khoury, Joseph, and David Langleben.
Division of Cardiology, The Sir Mortimer B. Davis Jewish General
Hospital and Lady Davis Institute for Medical Research, McGill
University, Montreal, Canada, H3T 1E2
APStracts 2:0176L, 1995.
Platelet-activating factor (PAF) is released from activated leukocytes
and endothelial cells in sepsis, lung injury and the Adult
Respiratory Distress Syndrome. With these disorders, pulmonary
hypertension develops, partly due to muscularization of the
microvasculature by proliferation of pericytes. PAF may be a mediator
of this process. Therefore, we examined the effects of PAF on in
-vitro growth of rat lung pericytes. As compared to control growth,
semi-synthetic PAF (10-9 M) stimulated the 7-day mean growth of
proliferating pericytes by 31% in medium with serum and 29% without
serum, and of previously growth-arrested pericytes by 12% with serum
and 23% without serum. These effects were blocked by the PAF-receptor
blocker CV-3988. PAF also increased 3H-thymidine incorporation into
pericytes by 79%. Synthetic 16:0-PAF stimulated pericyte growth, but
18:0 PAF did not. PAF exposure did not induce apoptosis in pericytes.
Thus, PAF compounds, similar to those found in-vivo, stimulate lung
pericyte growth in-vitro. PAF may act as a direct cytokine on cells
involved in muscularization of the pulmonary vessel walls.
Received 12 September 1994; accepted in final form 13 September
1995.
APS Manuscript Number L271-4.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95