肽类激素分泌机制的研究进展

肽类激素贮存在大型致密核芯分泌颗粒内,通过胞吐分泌,分泌颗粒被膜与细胞膜融合成单层,释放出全部内容物,或通过接触-分离的方式,多次部分释放。对新发现的孔体或融合孔的研究,揭示了分泌颗粒停泊、融合并释放出内容物的机制。排放到细胞外的囊泡内容物的消散速度,取决于融合孔的状态和囊泡内容物的化学性质。由于在细胞外存在完整的膜包分泌颗粒.因此,可能还存在着连同颗粒被膜的整体释放方式。

Mechanisms of Peptide Hormone Sectretion

Peptide hormones are stored in large dense-core vesicles.During exoeytosis,their cargo are released to the extracellular space completely when they fuse with and flatten into plasma membrane,or result in incomplete exocytosis by transient interactions with the plasma membrane as"kiss and run".The new structure‘porosome’or‘fusion pore’has been defined,where specific docking,fusion and vesicle swelling occur.The rate of disperse of vesicle cargo is dependent either on the properties of the fusion pore or on the chemical character of vesicle carge.Because some intact secretory granules coated with membrane were observed in extracellular solution,the release pattern might include a whole releasing together with membrane.