新生儿中性粒细胞活性氧代谢水平的研究  

Study on active oxygen metabolism of neutrophils in neonates

作　　者：步军[1] 孙建华[1] 黄萍[1] 敖黎明[1] 

机构地区：[1]上海第二医科大学附属新华医院上海儿童医学中心内科,200127

出　　处：《中华围产医学杂志》2005年第3期183-186,共4页Chinese Journal of Perinatal Medicine

摘　　要：目的　本研究通过对新生儿中性粒细胞吞噬细菌后所产生的活性氧自由基之一的超氧阴离子进行检测,以探讨新生儿中性粒细胞功能低下的部分原因。　方法　正常足月新生儿组23例,取脐带血加以两种活菌(金黄色葡萄球菌和大肠杆菌)刺激诱发中性粒细胞活性氧代谢,用超氧阴离子特异性探针氢化溴乙非啶进行细胞内染色,通过流式细胞仪对中性粒细胞超氧阴离子产生强度进行检测;正常成人对照组15例,取外周血进行相同实验。最后采用血浆置换法探讨体液因素在中性粒细胞活性氧代谢中的作用。　结果　足月新生儿的绝大部分中性粒细胞与正常成人细胞一样随细菌的吞噬而产生活性氧自由基。金黄色葡萄球菌刺激下新生儿中性粒细胞活性氧自由基产生水平与成人基本相同;而对于大剂量大肠杆菌的刺激,其自由基产生水平较成人明显低下[细菌细胞比40∶1,平均荧光强度(MFI) 347±70和461±55, t=2.63, P<0.05; 细菌细胞比80∶1, MFI 335±66和535±76, t=4.26, P<0.01]。用成人血浆替代新生儿自身血浆后,大肠杆菌刺激下新生儿中性粒细胞超氧阴离子产生水平显著提高(MFI:707±141和461±58, t=4.91, P<0.01)。　结论　全血条件下足月新生儿中性粒细胞活性氧自由基产生水平与所吞噬细菌的种类和数量有关,在大剂量大肠杆菌的刺激下活?Objective To investigate the causes of reduced function of neutrophils in neonates by measuring superoxide, one of the reactive oxygen species, produced by neutrophils following live bacterial phagocytosis in the whole blood. Methods Twenty-three cord blood samples were collected from normal full-term newborns and cultured with live Staphylococcus aureus and Escherichia coli. Blood cells were stained with Hydroethidine, an indicator of superoxide. The intensity of the superoxide of neutrophils were analyzed by flow cytometry. Fifteen adult blood samples were collected as control. Plasma replacement was used to study the function of body fluid in active oxygen metabolism of neutrophils. Results Most full-term neonatal neutrophils (PMNs) could produce superoxide anion following bacterial phagocytosis in the blood as that in adults. The level of superoxide production of term neonatal neutrophils, after stimulation of S. aureus, was as high as the adult′s but was significantly lower after stimulation by E. coli (bacteria cell ratio 40∶1, MFI 347±70 vs 461±55, P< 0.05; bacteria cell ratio 80∶1, MFI 335±66 vs 535±76, P<0.01). Superoxide production by neonatal neutrophils stimulated by E. coli increased significantly after replacing the neonatal plasma with adult′s plasma(MFI:707±141 vs 461±58, P<0.01). Conclusions The superoxide production by neonatal neutrophils is associated with the species and amount of stimulating bacteria. This production was suppressed by high dose of E. coli which might due to insufficiency of some humonal factors.

关 键 词：中性粒细胞 代谢水平 金黄色葡萄球菌 超氧阴离子 自由基产生 活性氧自由基 正常足月新生儿 活性氧代谢 大肠杆菌 平均荧光强度 细菌细胞 细胞内染色 特异性探针 流式细胞仪 血浆置换法 细胞吞噬 功能低下 正常成人 体液因素 

分 类 号：R722.1[医药卫生—儿科]