Extracellular calcium acts as a "third messenger" to regulate enzyme and alkaline secretion.
J Cell Biol
; 166(1): 111-9, 2004 Jul 05.
Article
em En
| MEDLINE
| ID: mdl-15240573
ABSTRACT
It is generally assumed that the functional consequences of stimulation with Ca2+ -mobilizing agonists are derived exclusively from the second messenger action of intracellular Ca2+, acting on targets inside the cells. However, during Ca2+ signaling events, Ca2+ moves in and out of the cell, causing changes not only in intracellular Ca2+, but also in local extracellular Ca2+. The fact that numerous cell types possess an extracellular Ca2+ "sensor" raises the question of whether these dynamic changes in external [Ca2+] may serve some sort of messenger function. We found that in intact gastric mucosa, the changes in extracellular [Ca2+] secondary to carbachol-induced increases in intracellular [Ca2+] were sufficient and necessary to elicit alkaline secretion and pepsinogen secretion, independent of intracellular [Ca2+] changes. These findings suggest that extracellular Ca2+ can act as a "third messenger" via Ca2+ sensor(s) to regulate specific subsets of tissue function previously assumed to be under the direct control of intracellular Ca2+.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carbacol
/
Adenina
/
Cálcio
/
Mucosa Gástrica
Limite:
Animals
Idioma:
En
Revista:
J Cell Biol
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Itália