Exocytosis

Japanese: exocytosis

…The secretion method in which secretions escape without damaging the cell body when observed under an optical microscope has been collectively called leaky secretion (eccrine secretion). However, observation under an electron microscope has led to the classification of leaky secretion into exocytosis and diacrine secretion. Exocytosis is mainly seen in cells that secrete peptides and proteins, and is a type in which secretory granules covering the limiting membrane approach the cell surface, then the limiting membrane and cell membrane fuse, the fusion point opens, and the granule contents escape. …

From [Cells]

…Enzymes in metabolic systems are not distributed uniformly, and efficient division of labor and assembly-line processes are established. The structure and function of such membrane systems have been well studied in the cases of exocytosis (release of substances outside the cell) and endocytosis (take of substances into the cell), and are well represented by the GERL system (Golgi apparatus → endoplasmic reticulum → lysosome). Each part of the GERL system, such as the rough endoplasmic reticulum membrane and smooth endoplasmic reticulum membrane, the membrane system and vesicles of the Golgi apparatus, the lysosomes and food vacuoles associated with phagocytosis, and the fusion of secretory granules and cell membranes during the secretion process, undergo a series of dynamic membrane flows, which are constantly accompanied by the generation and regeneration of membrane systems. …

From [Gland]

…(3) Eccrine secretion Under optical microscopy, secretions that do not damage the cell body are collectively called “eccrine secretion,” but under electron microscopy, they are divided into the following two types: (a) Exocytosis In this type, secretory granules covered with a limiting membrane approach the cell surface, then the limiting membrane and the cell membrane fuse, the fusion point opens, and only the granule contents are released. This type is observed in many proteinaceous secretory glands, such as various cells in the anterior pituitary gland, the endocrine and exocrine gland cells of the pancreas, and the serous cells of the salivary glands. …

*Some of the terminology that mentions "exocytosis" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…光学顕微鏡によって観察した場合に分泌物が細胞体を傷つけずに外へ出る分泌方式を総称して漏出分泌(エクリン分泌eccrine secretion)と呼んできた。しかし，電子顕微鏡での観察によって，漏出分泌は開口分泌exocytosisと透出分泌diacrine secretionに分けられるようになった。開口分泌はおもにペプチドやタンパク質を分泌する細胞にみられ，限界膜を覆った分泌顆粒が細胞の表面に近づき，ついで限界膜と細胞膜が癒合し，癒合点が開口し，顆粒内容物が外へ出る様式である。…

【細胞】より

…代謝系の酵素群は一様な分布をせず，効率のよい分業と流れ作業の工程ができ上がっている。このような膜系の構造と機能は，エクソサイトーシスexocytosis(細胞外への物質の放出)やエンドサイトーシスendocytosis(細胞内への物質の取り込み)の場合によく調べられており，GERL系(ゴルジ体Golgi apparatus→小胞体endoplasmic reticulum→リソソームlysosome)によってよく表されている。GERL系の各部分，粗面小胞体膜と滑面小胞体膜，ゴルジ体の膜系と小胞，食作用にともなうリソソームと食胞，分泌過程における分泌顆粒（かりゆう）と細胞膜の融合など一連のダイナミックな膜流動を行い，絶えず膜系の新生と再生をともなっている。…

【腺】より

…(3)漏出分泌eccrine secretion　光学顕微鏡的には，分泌物が細胞体を傷つけずに外へ出るものを総称して漏出分泌といってきたが，電子顕微鏡的には次の二つに分けられる。(a)開口分泌exocytosis　限界膜をかぶった分泌顆粒が細胞の表面に近づき，ついで限界膜と細胞膜が癒合し，癒合点が開口し，顆粒内容物だけが外へ出る様式である。脳下垂体前葉の各種細胞，膵臓の内外分泌腺細胞，唾液腺の漿液細胞など多数のタンパク質性分泌腺でこの形式が認められる。…

※「exocytosis」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典第２版について | 情報

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