The effect of meconium and amniotic fluid on alveolar macrophage function

The meconium aspiration syndrome (MAS) is an important cause of respiratory distress in newborn infants. Although numerous studies have examined prophylactic and therapeutic strategies for MAS, relatively little is known about the cellular pathophysiology of this syndrome, particularly in regard to alveolar macrophages. Since the meconium aspirated by neonates is necessarily diluted with amniotic fluid, the aim of this study was to examine the effect of both meconium and amniotic fluid on phagocytosis, respiratory burst, and production of proinflammatory cytokines in rat NR8383 alveolar macrophages.

Meconium was obtained from both human and equine neonates, and similar effects on the phagocytic and respiratory burst activity were observed following exposure of alveolar macrophages to meconium from either species.

The effect of meconium-exposure on the respiratory burst response in alveolar macrophages was quantified using flow cytometry to measure oxidation of dichlorofluorescin diacetate. (Abstract shortened by UMI.).