Calcium dependencies of regulated exocytosis in different endocrine cells

Title:

Calcium dependencies of regulated exocytosis in different endocrine cells

Creator:

Dolenšek, J., Skelin, M., and Rupnik, M. S.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:bb5c4b08-94fb-4035-9951-fcc37cea9365
uuid:bb5c4b08-94fb-4035-9951-fcc37cea9365

Subject:

Fyziologie člověka a srovnávací fyziologie, buňky, fyziologie, cells, physiology, calcium sensitivity, exocytosis, insulin-secreting cells, chromaffin cells, melanotrophs, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print

Description:

Exocytotic machinery in neuronal and endocrine tissues is sensitive to changes in intracellular Ca2+ concentration. Endocrine cell models, that are most frequently used to study the mechanisms of regulated exocytosis, are pancreatic beta cells, adrenal chromaffin cells and pituitary cells. To reliably study the Ca2+ sensitivity in endocrine cells, accurate and fast determination of Ca2+ dependence in each tested cell is required. With slow photo-release it is possible to induce ramp-like increase in intracellular Ca2+ concentration ([Ca2+]i) that leads to a robust exocytotic activity. Slow increases in the [Ca2+] i revealed exocytotic phases with different Ca2+ sensitivities that have been largely masked in step-like flash photo-release experiments. Strikingly, in the cells of the three described model endocrine tissues (beta, chromaffin and melanotroph cells), distinct Ca2+ sensitivity ‘classes’ of secretory vesicles have been observed: a highly Ca2+ -sensitive, a medium Ca2+ -sensitive and a low Ca2+ - sensitive kinetic phase of secretory vesicle exocytosis. We discuss that a physiological modulation of a cellular activity, e.g. by activating cAMP/PKA transduction pathway, can switch the secretory vesicles between Ca2+ sensitivity classes. This significantly alters late steps in the secretory release of hormones even without utilization of an additional Ca2+ sensor protein., J. Dolenšek, M. Skelin, M. S. Rupnik., and Obsahuje bibliografii a bibliografické odkazy

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2011 Volume:60 | Number:Suppl 1

Harvested from:

CDK

Metadata only:

false