Hernández D, De la Fuente M
Department of Animal Biology II (Animal Physiology), Faculty of Biological Science, Complutense University, Madrid, Spain.
Biochem Cell Biol. 1989 Jun;67(6):311-4. doi: 10.1139/o89-048.
Mannosephosphate isomerase (MPI) showed a higher activity than hexokinase (HKM) in its ability to phosphorylate mannose in the spleen, thymus, brain, liver, striated muscles, kidneys, and testes from BALB/c mice. This led to a HKM/MPI ratio of less than 1 in all the organs and tissues mentioned. In contrast, Ehrlich ascites tumor cells obtained from the peritoneum of BALB/c mice had low MPI activity (half of the HKM activity and, therefore, a ratio of 2). Mannose, which is nontoxic to nontumor cells at a concentration of 0.1 M, induced marked in vitro mortality of the tumor cells. Incubation of Ehrlich ascites tumor cells with mannose resulted in a high accumulation of mannose-6-phosphate and a marked depletion of ATP which did not appear when the cells were incubated with glucose. These facts may explain the selective mortality caused by mannose in the tumor cells studied.
甘露糖磷酸异构酶（MPI）在磷酸化BALB/c小鼠脾脏、胸腺、脑、肝、横纹肌、肾和睾丸中的甘露糖能力方面，比己糖激酶（HKM）表现出更高的活性。这导致在上述所有器官和组织中HKM/MPI比值小于1。相比之下，从BALB/c小鼠腹腔获得的艾氏腹水肿瘤细胞MPI活性较低（HKM活性的一半，因此比值为2）。浓度为0.1 M时对非肿瘤细胞无毒的甘露糖，可诱导肿瘤细胞在体外显著死亡。艾氏腹水肿瘤细胞与甘露糖孵育导致6-磷酸甘露糖大量积累以及ATP显著消耗，而细胞与葡萄糖孵育时则未出现这种情况。这些事实可能解释了所研究的肿瘤细胞中甘露糖引起的选择性死亡。
