Korean J Physiol Pharmacol.
1998 Aug;2(4):479-491.
Effect of the inhibition of platelet activating factor on oxidative
lung injury induced by interleukin-1 alpha
- Affiliations
-
- 1Department of Physiology, School of Medicine, Catholic University of Taegu-Hyosung, Taegu 705-034, South Korea.
Abstract
-
In order to know the pathogenesis of adult respiratory distress
syndrome (ARDS) in association with the oxidative stress by
neutrophils, the role of platelet activating factor
(1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, PAF) was investigated
during acute lung injury induced by interleukin-1alpha (IL-1) in rats.
An insufflation of IL-1 into the rat's trachea increased the
acetyltransferase activity in the lung and the increase of PAF content
was followed. As evidences of acute lung injury by neutrophilic
respiratory burst, lung leak index, myeloperoxidase activity, numbers
of neutrophils in the bronchoalveolar lavage fluid, neutrophilic
adhesions to endothelial cells and NBT positive neutrophils were
increased after IL-1 treatment. In addition, a direct instillation of
PAF into the trachea caused acute lung leak and the experimental
results
showed a similar pattern in comparison with IL-1 induced acute
lung injury. For the confirmation of oxidative stress during acute lung
leak by IL-1 and PAF, a histochemical electron microscopy was
performed. In IL-1 and PAF treated lungs of rats, the deposits of
cerrous perhydroxide were found. To elucidate the role of PAF, an
intravenous injection of PAF receptor antagonist, WEB 2086 was given
immediately after IL-1 or PAF treatment. WEB 2086 decreased the
production of hydrogen peroxide and the acute lung leak. In
ultrastructural study, WEB 2086 mitigated the pathological changes
induced by IL-1 or PAF. The nuclear factor kappa B (NFkB) was activated
by PAF and this activation was inhibited by WEB 2086 almost completely.
Based on these experimental results, it is suggested that the PAF
produced in response to IL-1 through the remodeling pathway has the
major role for acute lung injury by neutrophilic respiratory burst. In
an additional experiment, we can also come to conclude that the
activation of the NFkB by PAF is thought to be the fundamental
mechanism to initiate the oxidative stress by neutrophils causing
release of proinflammatory cytokines and activation of phospholipase
A2.