Leid R W, McConnell L A
Clin Immunol Immunopathol. 1983 Jul;28(1):67-76. doi: 10.1016/0090-1229(83)90189-7.
The larval stage of the tapeworm, Taenia taeniaeformis, was incubated in different concentrations of arachidonic acid. At various times after incubation, aliquots were removed for bioassay on either 38 microM aspirin or non-aspirin-treated equine platelets and by radioimmunoassay for the thromboxane A2 breakdown product, thromboxane B2 (TXB2). Platelet agonist activity was detected as early as 30 sec after addition of the arachidonic acid. In aspirin-treated platelets, this agonist activity peaked at 1 to 4 min and thereafter decayed rapidly with a time course that was both worm and arachidonic acid dependent. When assayed on non-aspirin-treated platelets the agonist activity was again detectable as early as 30 sec after addition of arachidonic acid, peaked at 1 to 3 min and then decayed very slowly over a 30-min period of incubation. It was found that levels of TXB2 were detected which increased over time concomitant with the decay of the platelet agonist activity. The most consistent detection of TXB2 generation was at 30 min with a mean of 49.6 pg and a range of 22.1 to 84.8 pg for four experiments. This report presents the first evidence for arachidonic acid utilization by a cestode or trematode and could in part provide an explanation for the marked cellular inflammation noted around dead or dying parasites.
绦虫——泡状带绦虫的幼虫阶段在不同浓度的花生四烯酸中进行孵育。孵育后的不同时间，取出一定量的孵育物，用于对38 microM阿司匹林处理或未处理的马血小板进行生物测定，并通过放射免疫测定法检测血栓素A2的分解产物血栓素B2（TXB2）。早在添加花生四烯酸后30秒就检测到血小板激动剂活性。在阿司匹林处理的血小板中，这种激动剂活性在1至4分钟时达到峰值，此后迅速衰减，其时间进程取决于蠕虫和花生四烯酸。当在未用阿司匹林处理的血小板上进行测定时，早在添加花生四烯酸后30秒又可检测到激动剂活性，在1至3分钟时达到峰值，然后在30分钟的孵育期内非常缓慢地衰减。结果发现，检测到的TXB2水平随着血小板激动剂活性的衰减而随时间增加。TXB2生成的最一致检测时间是30分钟，四个实验的平均值为49.6 pg，范围为22.1至84.8 pg。本报告首次提供了绦虫或吸虫利用花生四烯酸的证据，并且可以部分解释在死亡或即将死亡的寄生虫周围观察到的明显细胞炎症。
