Effects of phorbol ester on catecholamine secretion and protein phosphorylation in adrenal medullary cell cultures.
Proc Natl Acad Sci U S A
; 82(3): 930-4, 1985 Feb.
Article
em En
| MEDLINE
| ID: mdl-3156373
ABSTRACT
The effects of phorbol 12-myristate 13-acetate (PMA) on catecholamine secretion and protein phosphorylation from intact and digitonin-treated chromaffin cells were investigated. PMA (10-300 nM), an activator of protein kinase C, caused a slow Ca2+-dependent release of catecholamine from intact chromaffin cells that was potentiated by the Ca2+ ionophore ionomycin. PMA also enhanced secretion induced by Ba2+. In cells with plasma membranes rendered permeable by digitonin to Ca2+, ATP, and protein, PMA (100 nM) enhanced Ca2+-dependent secretion approximately 70% at 0.5 microM Ca2+ and 30% at 10 microM Ca2+. PMA enhanced the maximal response to Ca2+ approximately 25% and decreased the Ca2+ concentration required for half-maximal secretion approximately 30%. The effects of PMA on chromaffin cells were associated with a 2- to 3-fold increase in the phosphorylation of a 56-kDa protein that may be tyrosine hydroxylase. Other proteins were phosphorylated to a lesser extent. The experiments suggest that PMA increases protein kinase activity and secretion in chromaffin cells and raise the possibility that protein kinase C modulates catecholamine secretion in chromaffin cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Forbóis
/
Acetato de Tetradecanoilforbol
/
Proteínas
/
Norepinefrina
/
Medula Suprarrenal
Limite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
1985
Tipo de documento:
Article