Rkl. Bouhafs et C. Jarstrand, Interaction between lung surfactant and nitric oxide production by alveolar macrophages stimulated by group B streptococci, PEDIAT PULM, 30(2), 2000, pp. 106-113
The major etiologic agent in neonatal pneumonia and meningitis is group B s
treptococci (GBS). Nitric oxide (NO) production by alveolar macrophages (AM
) in response to Gram-positive bacteria such as GBS and the effect of surfa
ctant on this production have received little attention. We studied product
ion of NO by GBS-stimulated AM using the Griess reaction, the effect of lun
g surfactant on this NO production, and the possible lipid peroxidation (LP
O) of surfactant caused by NO. The LPO test was used to measure surfactant
peroxidation.
Heat-killed and live GBS were found to stimulate NO production by rat alveo
lar macrophages, and the presence of interferon gamma (IFN-gamma) increased
this stimulation in a synergistic manner. Curosurf(R), the natural surfact
ant used in our study, significantly reduced NO production in various sets
of experiments. Lipid peroxidation of surfactant was noted when NO was prod
uced by stimulated AM, a phenomenon that could be suppressed by NG-monometh
yl L-arginine (L-NMMA), the inhibitor of NO synthase.
In the lung of GBS-infected neonates, nitric oxide produced by AM might con
tribute to the destruction of surfactant caused by inflammatory cells. (C)
2000 Wiley-Liss. Inc.