Smith N C, Ovington K S, Boray J C
Department of Zoology, Australian National University, Canberra.
Int J Parasitol. 1992 May;22(3):281-6. doi: 10.1016/s0020-7519(05)80005-0.
Free radical generation by peritoneal leukocytes from hosts able to develop resistance to reinfection with Fasciola hepatica (rats) was compared with that of hosts unable to develop resistance (mice). Free radical generation by rat leukocytes was 3.5 times higher per cell and 30 times higher per animal than radical production by mouse leukocytes. The capacity of peritoneal leukocytes to produce free radicals in response to adult fluke crude antigen was increased by the presence of host plasma and was quantitatively greater in challenged rats than in naive or primary infected rats. This was not the case for mice, in which cells from primary infected animals were equally as responsive as cells from challenged mice. Further experiments revealed that challenge infection in rats apparently caused the in vivo activation of peritoneal leukocytes and increased levels of unidentified factors in plasma and that both of these responses were involved in the initiation of free radical generation in response to F. hepatica. Dramatic increases in the number of eosinophils present in the peritoneal cavities of primary infected and challenged rats (but not mice) were observed but the role of eosinophils in the production of free radicals in response to F. hepatica remains to be determined.
将能够对肝片吸虫再感染产生抗性的宿主（大鼠）的腹膜白细胞产生自由基的情况与不能产生抗性的宿主（小鼠）进行了比较。大鼠白细胞产生自由基的量，按每个细胞计算比小鼠白细胞高3.5倍，按每只动物计算则高30倍。宿主血浆的存在会增加腹膜白细胞对成虫粗抗原产生自由基的能力，且受到攻击的大鼠在数量上比未感染或初次感染的大鼠更大。小鼠的情况并非如此，初次感染动物的细胞与受到攻击的小鼠的细胞反应性相同。进一步的实验表明，大鼠的攻击感染显然导致了腹膜白细胞在体内的激活以及血浆中未鉴定因子水平的升高，并且这两种反应都参与了对肝片吸虫产生自由基的起始过程。观察到初次感染和受到攻击的大鼠（而非小鼠）腹腔中嗜酸性粒细胞数量显著增加，但嗜酸性粒细胞在对肝片吸虫产生自由基过程中的作用仍有待确定。
