Abstract:Objective This study examined the levels of the superoxide anion produced by neutrophils after different stimulations in neonates with isolated intrauterine growth restriction (IUGR) in order to clarify the effects of IUGR on activated oxygen metabolism of neutrophils in neonates. Methods Fifteen samples of cord venous blood from neonates with isolated IUGR (IUGR group) were stimulated with either phorbol myristate acetate (PMA) or bacteria (Staphylococcus aureus and Escherichia coli), and then stained with hydroethedine, an indicator of superoxide. The samples were analyzed on granulocyte gate by flow cytometry. The mean fluorescence for superoxide anion production was acquired, and was compared with 23 samples from normal full-term neonates (Control group). Results The superoxide anion level (demonstrated by mean fluorescence intensity, MFI) of the IUGR group was significantly higher than that of the Control group after PMA stimulation (448±131 vs 314±89; P< 0.01). Significant differences were also found in the superoxide anion level between the IUGR and Control groups after either Staphylococcus aureus or Escherichia coli stimulations (471±142 vs 362±79 and 502±133 vs 396±94; both P< 0.01). The ability of bacterial phagocytosis was the same for the two groups. Conclusions Neutrophils from neonates with isolated IUGR may be activated by some pathologic factors in uterus and yield an increased level of activated oxygen metabolism.
