English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Recent evidence indicates that osmotic forces may play a role in exocytosis. To examine this possibility and to investigate the osmotic properties of storage granules within cells, we investigated the effects of changes of osmolality on stability and function of cultured bovine chromaffin cells. Cell volume measurements indicated that the cells behaved as osmometers and that the intracellular osmolality rapidly equilibrated with the osmolality of the extracellular medium. Hyperosmotic solutions strongly inhibited nicotinic agonist-stimulated secretion but did not alter nicotinic agonist-stimulated Ca(2+) uptake. Hyperosmotic solutions also strongly inhibited elevated potassium- stimulated secretion but only weakly inhibited elevated K(+)-stimulated Ca(2+) uptake. Thus, hyperosmotic solutions inhibited secretion at a step after calcium entry. Cells exposed to 165 mOs(1) solutions did not lyse and retained their capacity to store and secrete catecholamine upon stimulation. Significant intracellular lysis of chromaffin granules occurred within cells exposed to lower osmolalities. In contrast, 75 percent of the catecholamine was released from granules from cultured cells or from fresh adrenal medulla incubated in vitro at 210 mOs. The data provide evidence for a role for osmotic forces in exocytosis and suggest that if osmotic stress of the granule occurs during exocytosis, then water influx into chromaffin granules increases granule volume by at least 70 percent. The results also indicate that the osmotic properties of the granules are altered upon homogenization and subcellular fractionation of the cells.

Effects of changes in osmolality on the stability and function of cultured chromaffin cells and the possible role of osmotic forces in exocytosis