宫内发育受限新生儿中性粒细胞活性氧代谢的研究

Activated oxygen metabol ism of neutrophils in neonates with intrauterine growth restriction

摘要:

目的 本研究拟通过对宫内发育受限新生儿中性粒细胞受不同刺激后所产生的超氧阴离子水平进行检测 ,并与正常新生儿进行比较 ,以了解宫内发育受限对于新生儿中性粒细胞活性氧代谢水平的影响 ,为进一步研究宫内发育受限对于新生儿整体免疫功能的影响打下基础。方法 选择 15例宫内发育受限新生儿脐静脉血 ,加以乙酸肉豆蔻佛波醇 (PMA)和两种细菌 (金黄色葡萄球菌和大肠杆菌 )刺激 ,用超氧阴离子特异性探针氢化溴乙非啶染色 ,通过流式细胞仪技术以平均荧光强度测定法对中性粒细胞超氧阴离子产生水平进行检测 ,并取正常足月新生儿脐带血 2 3例作为对照。结果 宫内发育受限新生儿中性粒细胞超氧阴离子产生水平 (以平均荧光强度MFI为计量单位 )在不同条件刺激下均与正常足月新生儿中性粒细胞有显著性差异 (PMA :4 4 8± 131vs 314± 89,P <0 .0 1;金黄色葡萄球菌 :4 71± 14 2vs 36 2± 79,P <0 .0 1;大肠杆菌 :5 0 2± 133vs 396± 94 ,P <0 .0 1) ;而其中性粒细胞细菌吞噬能力与正常足月儿相比无明显差异。结论 无明确诱因的宫内发育受限新生儿的中性粒细胞在宫内也可能被某些病理因素所激活 ,导致了细胞活性氧代谢水平的显著增高。

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.