Fried B, Tancer R B, Fleming S J
J Parasitol. 1980 Dec;66(6):1014-8.
In vitro pairing studies were done on chemically excysted metacercariae and on adults of Echinostoma revolutum maintained in vitro in agar-Locke's petri dish cultures at 39 +/- 1 C for up to 24 hr. Whereas newly excysted metacercariae did not pair, both immature and mature adults showed significant pairing. Adult echinostomes confined in dialysis sacs emitted excretory-secretory (EC) products which significantly attracted single echinostome adults in vitro. Only the lipophilic fraction of ES products was found to elicit attraction. Preparative TLC analysis of adult echinostomes produced three major bands as follows: I (phospholipids); II (free sterols); and III (free fatty acids + triglycerides). When tested in vitro, only the free sterol fraction significantly attracted single adult echinostomes. TLC and GLC analyses of free sterols of E. revolutum have indicated that cholesterol is the major free sterol.
在体外配对研究中，对化学脱囊的棘口吸虫后尾蚴以及在39±1℃的琼脂 - 洛克氏培养皿中体外培养长达24小时的卷棘口吸虫成虫进行了研究。新脱囊的后尾蚴不会配对，而成虫（包括未成熟和成熟的）则表现出显著的配对现象。限制在透析袋中的棘口吸虫成虫分泌排泄 - 分泌（ES）产物，这些产物在体外能显著吸引单个棘口吸虫成虫。仅发现ES产物的亲脂性部分能引发吸引作用。对棘口吸虫成虫进行制备性薄层层析分析产生了三条主要条带，如下所示：I（磷脂）；II（游离固醇）；III（游离脂肪酸 + 甘油三酯）。在体外测试时，只有游离固醇部分能显著吸引单个成虫。对卷棘口吸虫游离固醇的薄层层析和气相色谱分析表明，胆固醇是主要的游离固醇。
