Ekholm S E, Morris T W, Fonte D, Marinetti G V, Simon J H, Leakey P, Prentice L
Department of Radiology, University of Rochester Medical Center, Rochester, NY 14642.
Invest Radiol. 1989 Feb;24(2):145-9. doi: 10.1097/00004424-198902000-00011.
The authors previously showed that metrizamide causes an inhibition in CO2 production in rat neural tissue. The purposes of this work were to test if this inhibition was the result of a competitive inhibition of metrizamide with the D-glucose transport system and to test the effect of other contrast media. Deoxyglucose was used as a marker for glucose. The first cellular system using rat hippocampus slices was designed to examine the effect of 15 mM and 80 mM metrizamide on deoxyglucose uptake. The second cell-free system, using isolated rat brain synaptosomes, was designed to evaluate more accurately the mechanism and kinetics of metrizamide's inhibitory effect on the uptake of deoxyglucose and to compare metrizamide to other nonionic contrast media (iohexol, iopamidol, iotrol, and iodixanol). These experiments demonstrate that there is inhibition of D-glucose uptake only in hippocampus slices and that the inhibition is dependent on the concentration of metrizamide. This does not, however, appear to be a competitive inhibitory effect on the carrier such as that between D-glucose and 2-deoxy-D-glucose. In synaptosomes, none of the contrast media had a significant effect on the uptake of 2-deoxyglucose.
作者们之前表明，甲泛葡胺会抑制大鼠神经组织中的二氧化碳生成。这项工作的目的是测试这种抑制作用是否是甲泛葡胺与D - 葡萄糖转运系统竞争性抑制的结果，以及测试其他造影剂的效果。脱氧葡萄糖被用作葡萄糖的标记物。第一个使用大鼠海马切片的细胞系统旨在研究15 mM和80 mM甲泛葡胺对脱氧葡萄糖摄取的影响。第二个无细胞系统，使用分离的大鼠脑突触体，旨在更准确地评估甲泛葡胺对脱氧葡萄糖摄取抑制作用的机制和动力学，并将甲泛葡胺与其他非离子型造影剂（碘海醇、碘帕醇、碘曲仑和碘克沙醇）进行比较。这些实验表明，仅在海马切片中存在对D - 葡萄糖摄取的抑制作用，且这种抑制作用取决于甲泛葡胺的浓度。然而，这似乎并非对载体的竞争性抑制作用，如D - 葡萄糖与2 - 脱氧 - D - 葡萄糖之间的那种抑制作用。在突触体中，没有一种造影剂对2 - 脱氧葡萄糖的摄取有显著影响。
