Pappas P W, Durka G M
Department of Zoology, Ohio State University, Columbus 43210-1293.
Parasitology. 1993 Feb;106 ( Pt 2):201-9. doi: 10.1017/s0031182000075004.
When incubated in vitro for 24 h, intact eggs, chemically shelled eggs (obtained by treating intact eggs with NaOCl), activated larvae (eggs in which the outer shell and inner envelope were removed), and oncospheres (activated larvae treated with papain to remove the embryophore) absorb and metabolize radioactive glucose. Intact eggs, which are covered by the impermeable shell, absorb only small amounts of exogenous radioactive glucose, while chemically shelled eggs, activated larvae, and oncospheres absorb much larger amounts. Only very small amounts of the exogenous glucose are incorporated into the ethanol-precipitable carbohydrate fraction (which would include glycogen) by any of the preparations of eggs/larvae. However, the glucose is incorporated into higher molecular weight end-products that are liberated into the incubation medium. There is a temporal shift in the ability of activated larvae and oncospheres to metabolize exogenous glucose. Activated larvae and oncospheres absorb but do not metabolize glucose during the first 8 h post-activation. Between 8 and 16 h post-activation, however, virtually all of the absorbed glucose is metabolized into higher molecular weight end-products that are liberated into the incubation media. This temporal shift suggests that activation of oncospheres and cysticercoid morphogenesis are accompanied by distinct changes in carbohydrate metabolism.
在体外孵育24小时时，完整的虫卵、化学去壳虫卵（通过用次氯酸钠处理完整虫卵获得）、活化幼虫（去除了外壳和内包膜的虫卵）以及六钩蚴（用木瓜蛋白酶处理活化幼虫以去除胚膜）均能吸收并代谢放射性葡萄糖。被不透水的外壳覆盖的完整虫卵仅吸收少量外源性放射性葡萄糖，而化学去壳虫卵、活化幼虫和六钩蚴吸收的量则大得多。任何虫卵/幼虫制剂仅将极少量的外源性葡萄糖掺入乙醇可沉淀的碳水化合物部分（其中包括糖原）。然而，葡萄糖被掺入释放到孵育培养基中的更高分子量的终产物中。活化幼虫和六钩蚴代谢外源性葡萄糖的能力存在时间上的变化。活化幼虫和六钩蚴在活化后的前8小时吸收但不代谢葡萄糖。然而，在活化后8至16小时之间，几乎所有吸收的葡萄糖都被代谢为释放到孵育培养基中的更高分子量的终产物。这种时间上的变化表明，六钩蚴的活化和似囊尾蚴形态发生伴随着碳水化合物代谢的明显变化。
