"Positive correlation between cytosolic free calcium and surfactant sec" by Mark S. Pian, Leland G. Dobbs et al.
 

Positive correlation between cytosolic free calcium and surfactant secretion in cultured rat alveolar type II cells

ORCiD

Nejat Düzgüneş: 0000-0001-6159-1391

Department

Biomedical Sciences

Document Type

Article

Publication Title

Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism

ISSN

0005-2760

Volume

960

Issue

1

DOI

10.1016/0005-2760(88)90007-0

First Page

43

Last Page

53

Publication Date

5-2-1988

Abstract

To determine whether increases in the cytosolic free Ca2+ concentration ((Ca2+]i) accompany agoniststimulated surfactant secretion by cultured alveolar type II cells, we measured the [Ca2+]i of quin2-loaded cells isolated from adult rats before and after cells were stimulated with ionomycin, terbutaline or tetradecanoylphorbol acetate (TPA). To determine whether increases in [Ca2+]i are necessary for stimulated surfactant secretion to occur, we measured secretion in cells after [Ca2+]i had been reduced by loading cells with quinl in medium containing low [Ca2+]. Ionomycin increased [Ca2+]i and stimulated surfactant secretion in a dose-dependent manner. Reductions in [Ca2+]i correlated with reductions in secretion stimulated by ionomycin, terbutaline or TPA. Ionomycin-stimulated secretion was most sensitive to reductions in [Ca2+]i; terbutaline-stimulated secretion was more sensitive than TPA-stimulated secretion. When [Ca2+]i was less than 65 nM, all stimulated secretion was blocked. Restoration of [Ca2+]i to greater than 100 nM restored ionomycin-stimulated secretion. We conclude that ionomycin increases [Ca2+]i and stimulates surfactant secretion in cultured alveolar type II cells, and that increased [Ca2+]i appears to be necessary for ionomycin-stimulated secretion to occur. Terbutaline-stimulated surfactant secretion seems to be more easily inhibited by a reduction in [Ca2+]i than does TPA-stimulated secretion. © 1988.

Link to Full Text

Share

COinS