Cummins A G, Bolin T D, Duncombe V M, Davis A E
Parasitology. 1986 Dec;93 ( Pt 3):539-46. doi: 10.1017/s0031182000081245.
Faecal blood loss was measured during Nippostrongylus brasiliensis infection in the DA rat using 51Cr-labelled red blood cells (r.b.c.s). In an initial study, faecal blood loss was measured on day 7 of primary infection with 3000 larvae administered subcutaneously (s.c.), and found to be 0.03 ml/24 h in uninfected animals and 0.14 ml/24 h in infected animals. In a further experiment, blood loss was measured on the day before infection and for 13 days after primary s.c. infection with 5000 larvae. Faecal blood loss was 0.05 ml/24 h or less until day 3, began to rise from day 5, reached a peak of 0.51 ml/24 h on day 8, and fell until day 13. This was closely associated with the rise and fall of the pooled faecal egg count. Direct worm count confirmed a high worm burden on day 7 and expulsion by day 14. The effect of the worm burden on the haemoglobin concentration (Hb) was measured in a further experiment and showed a fall in Hb with a mean worm burden of 726 compared to that of 47 or 284 worms. The study concluded that there is minimal background blood loss in uninfected rats but that infection with N. brasiliensis is a cause of intestinal blood loss and this is associated with a fall in Hb concentration that is dependent on the worm burden.
采用51Cr标记的红细胞（r.b.c.s）测定了巴西日圆线虫感染期间DA大鼠的粪便失血量。在一项初步研究中，对皮下注射（s.c.）3000条幼虫进行初次感染的第7天测量了粪便失血量，发现未感染动物为0.03 ml/24小时，感染动物为0.14 ml/24小时。在进一步的实验中，在感染前一天以及皮下初次感染5000条幼虫后的13天内测量失血量。粪便失血量在第3天前为0.05 ml/24小时或更少，从第5天开始上升，在第8天达到0.51 ml/24小时的峰值，然后下降至第13天。这与合并粪便虫卵计数的升降密切相关。直接蠕虫计数证实第7天蠕虫负荷高，到第14天被排出。在进一步的实验中测量了蠕虫负荷对血红蛋白浓度（Hb）的影响，结果显示平均蠕虫负荷为726条时Hb下降，而蠕虫负荷为47条或284条时则不然。该研究得出结论，未感染大鼠的背景失血量极少，但巴西日圆线虫感染是肠道失血的一个原因，并且这与Hb浓度下降有关，Hb浓度下降取决于蠕虫负荷。
