Am. J. Respir. Crit. Care Med., Vol 155, No. 5, May 1997, 1624-1628.
Mepacrine decreases lung leak in rats given interleukin-1 intratracheally
YM Lee, BM Hybertson, LS Terada, AJ Repine, HG Cho and JE Repine
Webb-Waring Institute for Biomedical Research and the Department of Medicine at the University of Colorado Health Sciences Center, Denver, USA.
We hypothesized that phospholipase A2 (PLA2) metabolites contribute to the
acute, neutrophil-dependent, edematous lung leak that develops after
administration of interleukin-1 (IL-1) intratracheally to rats and tested
this premise by using mepacrine to inhibit PLA2 activity in vivo. We found
that lung PLA2 activity, lung lavage phospholipid content, lung leak index,
lung weight gain, and lung lavage protein concentrations were increased in
rats given IL-1 intratracheally compared with sham-treated control rats. By
comparison, lungs of mecaprine and IL-1-treated rats had decreased PLA2
activity, lavage phospholipid content, leak, weight gain, and lavage
protein increases compared with rats given IL-1 intratracheally. Mepacrine
treatment also decreased lung neutrophil accumulation, but not lung lavage
cytokine- induced neutrophil chemoattractant (CINC) levels, in rats given
IL-1 intratracheally. In parallel experiments, mepacrine treatment reduced
the adhesion of human neutrophils to IL-1-treated human umbilical vein
endothelial cells in vitro. Our results indicate that PLA2 activity
participates in the lung neutrophil retention and pulmonary vascular leak
that develops in rats given IL-1 intratracheally.