Horadagoda N U, Hodgson J C, Moon G M, Wijewardana T G, Eckersall P D
Department of Veterinary Paraclinical Studies, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka.
Res Vet Sci. 2002 Jun;72(3):194-200. doi: 10.1053/rvsc.2001.0538.
Clinical changes and acute phase responses, including tumour necrosis factor-alpha (tnfalpha), in six buffalo calves were examined following intravenous inoculation of a bolus of endotoxin (1 microg kg(-1) bodyweight in 10 ml of phosphate-buffered saline [ pbs ]) extracted from Pasteurella multocida serotype B:2, the bacterium responsible for haemorrhagic septicaemia (hs) in Asia. Endotoxin injection caused a rapid onset of clinical signs characterised by dullness, sternal recumbency, elevated rectal temperatures, excessive salivation and dyspnoea that lasted for up to 12 hours post-inoculation (p.i.). Serum concentrations of tnfalpha rose within 1 hour p.i. to reach peak values ranging between 8 and 140 ng ml(-1) at 1-2 hours p.i. and then declined rapidly to baseline levels 3-5 hours p.i. Endotoxin injection induced other acute phase changes, including a rapid leucopenia and reductions in the serum concentrations of iron and zinc and a delayed but prolonged increase in haptoglobin from 12 hours p.i. that reached a plateau from about 60 hours p.i. Three control calves injected with 10 ml pbs showed no clinical or blood compositional changes. By reproducing key signs of hs the work confirms a pivotal role of endotoxin in the pathogenesis of hs and emphasises the exquisite sensitivity of the buffalo to P multocida endotoxin.
对六头水牛犊静脉注射从多杀性巴氏杆菌B:2型(亚洲地区引起出血性败血症的病原菌)提取的大剂量内毒素(1微克/千克体重,溶于10毫升磷酸盐缓冲盐水 [PBS])后,检测了包括肿瘤坏死因子-α(TNFα)在内的临床变化和急性期反应。内毒素注射后迅速出现临床症状,表现为精神沉郁、胸卧、直肠温度升高、流涎过多和呼吸困难,这些症状在接种后持续长达12小时。血清TNFα浓度在接种后1小时内升高,在接种后1 - 2小时达到8至140纳克/毫升的峰值,然后在接种后3 - 5小时迅速降至基线水平。内毒素注射还引发了其他急性期变化,包括迅速出现白细胞减少、血清铁和锌浓度降低,以及接种后12小时开始出现但持续时间较长的触珠蛋白增加,从接种后约60小时达到平台期。三只注射10毫升PBS的对照犊牛未出现临床或血液成分变化。通过重现出血性败血症的关键症状,该研究证实了内毒素在出血性败血症发病机制中的关键作用,并强调了水牛对多杀性巴氏杆菌内毒素的高度敏感性。