Elferink J G
Department of Medical Biochemistry, University of Leiden, The Netherlands.
Cell Biochem Funct. 1992 Mar;10(1):35-40. doi: 10.1002/cbf.290100107.
Protamine induces a gradual change in plasma membrane permeability in rabbit neutrophils, which is evident from the increase of indol fluorescence, and the leakage of quin2 from quin2-loaded neutrophils. The influx of extracellular Ca2+ into the neutrophil provides an explanation for exocytosis which occurs in the presence of Ca2+ and protamine. The dependence of exocytosis on Ca2+ concentration follows the same pattern as is observed in neutrophils permeabilized by other means. In the absence of Ca2+, and in the presence of protamine, La3+ has an activating effect on exocytosis. At higher concentrations La3+ inhibits exocytosis that occurs in the presence of Ca2+ and protamine, as do some other metal ions. The resemblance between the membrane effects of a number of toxins, as reported in literature, and protamine-induced membrane damage suggests that they occur via the same mechanism.
鱼精蛋白可使兔中性粒细胞的质膜通透性逐渐发生变化，这从吲哚荧光增强以及喹啉2从负载喹啉2的中性粒细胞中泄漏可明显看出。细胞外Ca2+流入中性粒细胞为在Ca2+和鱼精蛋白存在时发生的胞吐作用提供了解释。胞吐作用对Ca2+浓度的依赖性与通过其他方法使中性粒细胞通透时观察到的模式相同。在无Ca2+且存在鱼精蛋白的情况下，La3+对胞吐作用有激活作用。在较高浓度时，La3+会抑制在Ca2+和鱼精蛋白存在时发生的胞吐作用，其他一些金属离子也有同样的作用。文献报道的多种毒素的膜效应与鱼精蛋白诱导的膜损伤之间的相似性表明，它们是通过相同的机制发生的。
