Ablett J M, Fairbairn S M, Page C P, Lees P, Cunningham F M
Department of Veterinary Basic Sciences, Royal Veterinary College, Herts, UK.
Equine Vet J. 1997 Sep;29(5):382-6. doi: 10.1111/j.2042-3306.1997.tb03144.x.
A role for platelets in allergic airways disease has been postulated and changes in the responsiveness of circulating platelets have been demonstrated following antigen challenge of asthmatic human subjects. In this study agonist-induced aggregation of equine platelets in vitro has been compared before and after exposure of horses to a controlled hay and stray challenge. Prior to challenge the response of platelets, from horses with chronic obstructive pulmonary disease (COPD) and normal animals, to adenosine diphosphate (ADP) and platelet activating factor (PAF) did not differ. Five hours after initiation of the challenge, there was a modest but significant decrease in the response of platelets from the COPD horses to PAF, but not to ADP. Platelets from normal horses were not less sensitive to either agonist at this time. Twenty four hours after challenge the responses of platelets from COPD horses to both agonists were the same as pre-challenge values. These results demonstrate that antigen challenge alters the responsiveness of platelets from allergic horses to PAF and this change is suggestive of PAF release accompanying allergen exposure in the horse.
血小板在过敏性气道疾病中的作用已被提出，并且在哮喘患者接受抗原激发后，已证实循环血小板的反应性发生了变化。在本研究中，比较了马匹在接触受控干草和过敏原激发前后，体外激动剂诱导的马血小板聚集情况。在激发前，患有慢性阻塞性肺疾病（COPD）的马匹和正常动物的血小板对二磷酸腺苷（ADP）和血小板活化因子（PAF）的反应没有差异。激发开始后5小时，COPD马匹的血小板对PAF的反应有适度但显著的下降，但对ADP的反应没有下降。此时，正常马匹的血小板对这两种激动剂的敏感性并没有降低。激发后24小时，COPD马匹的血小板对两种激动剂的反应与激发前的值相同。这些结果表明，抗原激发改变了过敏性马匹血小板对PAF的反应性，这种变化提示在马匹接触过敏原时伴有PAF的释放。
