Intracellular Signals in Stimulation of Enzyme Secretion from Exocrine Glands

Schulz, Irene; Streb, Hanspeter; Thévenod, Frank

doi:10.1007/978-3-642-70744-5_15

Cited by 2 publications

(2 citation statements)

References 19 publications

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“…The activity of most actin-associated proteins depends on the intracellular Ca 2+ concentration [Burn, 1988;Walker, 1988;Yin et al, 1988;Shariff and Luna, 1992], which in turn controls fundamental steps of exocytosis (stimulussecretion model) [Schulz et al, 1986;Knight, 1987]. Therefore, the actin filament system is an ideal candidate for playing a crucial part in the complex motile events in the gastric epithelium.…”

Section: Introductionmentioning

confidence: 99%

Electron-Microscopic Detection of Cytoskeletal Actin in the Epithelial Cells of Bovine Abomasum

Sommer¹,

Kressin²,

Schnorr³

1998

Cells Tissues Organs

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The fine structural distribution of cytoskeletal actin was investigated in the oxyntic gland region and in the pyloric gland region of bovine abomasal mucosa using immunoelectron methods. In all exocrine cell types of the gastric epithelium, actin filaments exhibit a polarized pattern of distribution. In the members of the mucus- and protein-synthesizing cell line, the actin filaments form a prominent barrier to the exocytosis of secretory granules underneath the apical membrane. Therefore, actin is supposed to be involved in the control of exocytosis. The basolateral subplasmalemmal cortex of the exocrine cells, however, shows weaker labeling for actin filaments. In this position actin might be responsible for the movement of epithelial cells along the length of the gastric gland during physiological cell renewal and for the maintenance of the integrity of the epithelial unit and of cell polarization. In parietal cells of bovine abomasum, actin filaments are, in addition, associated with the intracellular canaliculus, but not with the tubulovesicular compartment. We assume that actin filaments reorganize the canalicular membrane after membrane translocations in the course of acid secretion. For the first time, actin filaments were documented in the rare brush cell type of bovine abomasum, where they do not form a terminal web beneath the apical membrane and therefore point out the nonexocrine function of the brush cell type. In all polarized cells of the bovine abomasum, actin filaments underlay the two apical members of the junctional complex, the tight junction and the adherens junction, where they might be involved in the regulation of cell adhesion, cell motility and cell shape determination.

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Section: Introductionmentioning

confidence: 99%

Electron-Microscopic Detection of Cytoskeletal Actin in the Epithelial Cells of Bovine Abomasum

Sommer¹,

Kressin²,

Schnorr³

1998

Cells Tissues Organs

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“…One of these is the process of exocytotic secretion. Temporary elevation of the concentration of intracellular ionized Ca2+ is thought to be a primary event in the initiation of secretion in response to physiologic stimuli (stimulus-secretion cou pling) [1,2] in the majority of secretory cells.…”

Section: Introductionmentioning

confidence: 99%

Intracellular Enzyme Localization in the Epithelium of the Bovine Glandular Stomach

Schessner¹,

Schnorr²

1990

Cells Tissues Organs

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The intracellular localization of calcium adenosine triphosphatase (Ca²⁺-ATPase) was studied ultracytochemically in the pyloric glands of the abomasal mucosa of cattle. A remarkable staining pattern exhibited the Golgi apparatus, as there was a gradation in staining of the interior sides of dictyosomal cisternae from the not or weakly stained cis to the heavily stained trans face. Membranes of Golgi-endoplasmic reticulum lysosome complex-secretory vesicles showed either no or strong enzyme activity. Membranes of secretory vesicles accumulated in the cell apex stained positive for ATPase activity. This accounts also for the apical cortical cytoplasm. From these results it is speculated that Ca²⁺-ATPase may play an important role in the pathway of exocytotic secretion, especially in the process of membrane sorting and biogenesis of secretory vesicles, in the steps of vesicle accumulation and transport to the site of exocytosis as well as in membrane fusion events.

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Intracellular Signals in Stimulation of Enzyme Secretion from Exocrine Glands

Cited by 2 publications

References 19 publications

Electron-Microscopic Detection of Cytoskeletal Actin in the Epithelial Cells of Bovine Abomasum

Electron-Microscopic Detection of Cytoskeletal Actin in the Epithelial Cells of Bovine Abomasum

Intracellular Enzyme Localization in the Epithelium of the Bovine Glandular Stomach

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