Pappas P W, Durka G M
Department of Zoology, Ohio State University, Columbus 43210-1293.
Parasitology. 1993 Apr;106 ( Pt 3):317-25. doi: 10.1017/s0031182000075144.
When incubated in vitro for 24 h, oncospheres of Hymenolepis diminuta absorb and metabolize radioactive glucose. Between 0 and 12 h post-activation, oncospheres absorb glucose, but glucose is neither metabolized into other carbohydrates nor incorporated into the ethanol-precipitable fraction (which would contain glycogen). Between 12 and 24 h post-activation glucose is incorporated into a number of higher molecular weight carbohydrates that are demonstrable in ethanol extracts of the larvae, as well as the incubation media. Furthermore, measurable amounts of radioactivity are incorporated into the ethanol-precipitable carbohydrate fraction of oncospheres. To determine if these temporal changes in carbohydrate metabolism occurred spontaneously following activation, oncospheres were pre-incubated for 12 h (0-12 h post-activation) in the absence or presence of glucose, and then transferred to media containing radioactive glucose for an additional 12 h (12-24 h post-activation). In these latter experiments, glucose absorption and metabolism between 12 and 24 h post-activation were virtually identical to glucose metabolism in oncospheres that were incubated in radioactive glucose for 0-12 h immediately following activation. Thus, these data do not support the hypothesis that the temporal shift in carbohydrate metabolism occurs spontaneously.
微小膜壳绦虫六钩蚴在体外培养24小时后，会吸收并代谢放射性葡萄糖。在激活后的0至12小时内，六钩蚴吸收葡萄糖，但葡萄糖既不代谢为其他碳水化合物，也不掺入乙醇可沉淀部分（其中会含有糖原）。在激活后的12至24小时内，葡萄糖掺入了一些分子量较高的碳水化合物中，这些碳水化合物在幼虫的乙醇提取物以及培养介质中都可检测到。此外，可测量到的放射性被掺入六钩蚴的乙醇可沉淀碳水化合物部分。为了确定碳水化合物代谢的这些时间变化是否在激活后自发发生，将六钩蚴在不存在或存在葡萄糖的情况下预孵育12小时（激活后0至12小时），然后转移到含有放射性葡萄糖的培养基中再培养12小时（激活后12至24小时）。在这些后续实验中，激活后12至24小时的葡萄糖吸收和代谢与激活后立即在放射性葡萄糖中培养0至12小时的六钩蚴中的葡萄糖代谢几乎相同。因此，这些数据不支持碳水化合物代谢的时间变化是自发发生的这一假设。
