Direct and phagocyte-mediated lipid peroxidation of lung surfactant by group B streptococci.
Lung
; 178(5): 317-29, 2000.
Article
em En
| MEDLINE
| ID: mdl-11147315
ABSTRACT
In newborn infants, group B streptococci (GBS) often cause pneumonia, with polymorphonuclear leukocytes (PMN) migrating into the lungs. Because surfactant therapy may be needed in such patients, we evaluated the interaction between GBS or GBS-stimulated PMN and a surfactant preparation (Curosurf) in vitro. The superoxide production of GBS strains or GBS-activated PMN was measured, using the nitroblue tetrazolium (NBT) test and the subsequent lipid peroxidation (LPO) as the content of malondialdehyde (MDA) and 4-hydroxyalkenals (4-HNE). The growth of GBS in surfactant was determined and related to the LPO. Finally, the effect of LPO on surfactant activity, caused by GBS-stimulated PMN, was assessed by measuring dynamic surface tension in a pulsating bubble surfactometer. Curosurf diminished the NBT reduction by both live GBS and GBS-stimulated PMN. Surfactant was peroxidized by reactive oxygen species (ROS) from both GBS and GBS-stimulated PMN in a time-dependent manner. Vitamin E significantly reduced the peroxidation level of surfactant in both cases. Surfactant peroxidation was associated with a reduction in the number of live bacteria. The biophysical activity of Curosurf was impaired by GBS-stimulated PMN, as reflected by increased minimum surface tension during cyclic compression. These findings indicate that Curosurf undergoes LPO by ROS produced by GBS and/or PMN. We speculate that exogenous surfactant preparations should be supplemented with vitamin E or another antioxidant, when given to infants with GBS pneumonia.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfolipídeos
/
Streptococcus agalactiae
/
Produtos Biológicos
/
Surfactantes Pulmonares
/
Peroxidação de Lipídeos
/
Espécies Reativas de Oxigênio
/
Ativação de Neutrófilo
/
Neutrófilos
Limite:
Adult
/
Humans
Idioma:
En
Revista:
Lung
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Suécia