Dunant Y
Département de pharmacologie, CMU, Genève, Switzerland.
Cell Biol Int. 1994 May;18(5):327-36. doi: 10.1006/cbir.1994.1082.
Distinct mechanisms operate in different secreting systems, they are 1) free diffusion through the plasma membrane; 2) exocytosis resulting from fusion of a secretory granule with the plasma membrane; 3) fleeting release from a granule through a transient pore without full fusion; 4) release through a specialised plasmalemmal molecule such as the mediatophore. The latter mechanism is proposed to operate in rapid synapses in which the neurotransmitter is emitted as an abrupt chemical impulse of quantal composition. There, release is momentarily signalled in the plasma membrane by large intramembrane particles. Synaptic vesicles are also essential for regulation of this type of release. They fuse with the plasma membrane only late after activity and seem to be involved in calcium sequestration and extrusion.
不同的分泌系统有不同的作用机制，它们是：1）通过质膜的自由扩散；2）分泌颗粒与质膜融合导致的胞吐作用；3）通过短暂孔隙从颗粒中短暂释放而不发生完全融合；4）通过专门的质膜分子如介质载体释放。有人提出后一种机制在快速突触中起作用，在这种突触中神经递质以量子组成的突发化学冲动形式释放。在那里，质膜中的大膜内颗粒会瞬间发出释放信号。突触小泡对于这种类型的释放调节也至关重要。它们仅在活动后期与质膜融合，似乎参与钙的螯合和排出。
