Marxen P, Ahnert-Hilger G, Wellhöner H H, Bigalke H
Medical School of hannover, Dept of Pharmacology and Toxicology, F.R.G.
Toxicon. 1990;28(9):1077-82. doi: 10.1016/0041-0101(90)90146-x.
Tetanus toxin blocks Ca2(+)-evoked catecholamine release from permeabilized bovine adrenal chromaffin cells preloaded with gangliosides. Tetanus toxin preincubated with its specific antibodies F(ab')2 is without any effect on exocytosis. Specific antitetanus F(ab')2 presented to chromaffin cells which are pretreated with tetanus toxin and permeabilized by digitonin cannot restore exocytosis. Under the same conditions, however, 125I-labeled F(ab')2 accumulates in chromaffin cells. The accumulation depends on the presence and concentration of tetanus toxin and can be prevented by an excess of unlabeled F(ab')2. Once tetanus toxin has initiated block of exocytosis, it cannot be neutralized by binding to its specific antibody.
破伤风毒素可阻断钙离子诱导的、来自预先加载神经节苷脂的通透化牛肾上腺嗜铬细胞的儿茶酚胺释放。与特异性抗体F(ab')2预孵育的破伤风毒素对胞吐作用没有任何影响。将特异性抗破伤风F(ab')2作用于经破伤风毒素预处理并用洋地黄皂苷通透化的嗜铬细胞，不能恢复胞吐作用。然而，在相同条件下，125I标记的F(ab')2会在嗜铬细胞中积累。这种积累取决于破伤风毒素的存在和浓度，并且可以被过量的未标记F(ab')2所阻止。一旦破伤风毒素启动了对胞吐作用的阻断，它就不能通过与特异性抗体结合而被中和。
