Work

Catecholamine secretion from digitonin-treated adrenal medullary chromaffin cells.

Year: 1983

Type: article

Abstract: The plasma membrane of cultured chromaffin cells from bovine adrenal medulla was rendered leaky by incubation in low concentrations of digitonin. Digitonin (20 microM) induced Ca2+-dependent release of 10-20% of the catecholamine in the presence of 10 microM Ca2+ without addition of secretagogue. Half-maximal catecholamine release occurred at approximately 1 microM Ca2+ x Mg2+ could not substitute for Ca2+. Cells incubated with digitonin rapidly lost their ability to exclude trypan blue. Digitonin caused release of the cytosolic markers lactic dehydrogenase and phenylethanolamine-N-methyltransferase, but, in contrast to release of catecholamine, the release of the cytosolic proteins was inhibited by Ca2+. Soluble dopamine-beta-hydroxylase, a protein marker of granule contents, was released proportionally with catecholamine in a Ca2+ dependent manner. Catecholamine release was optimal in solutions containing MgATP. Hence, digitonin-treated cells, although they lose soluble cytosolic proteins and presumably low molecular weight cytosolic constituents, maintain the Ca2+-dependent reactions of exocytosis in the presence of MgATP. Digitonin-treated chromaffin cells may be a powerful system in which to study the biochemical mechanisms underlying exocytosis.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(18)32526-2

Authors: L A Dunn, R W Holz

Institution: University of Michigan

Language: English

Topic: Cellular transport and secretion

Subfield: Cell Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,430