Sphingosine stimulates calcium mobilization in rat parotid acinar cells

FEBS Letters

Sugiya, Hiroshi¹  Furuyama, Shunsuke¹ 

[1] Department of Physiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271, Japan

关键词: Sphingosine;    Ca2+ mobilization;    Protein kinase C (rat parotid);   

DOI  :  10.1016/0014-5793(91)80953-Z

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In fura-2-loaded parotid acinar cells, 50–200 μM sphingosine induced an increase in cytosolic Ca²⁺ ([Ca²⁺]_i). When extracellular Ca²⁺ was chelated by EGTA, 50 μM sphingosine failed to increase [Ca²⁺]_i, but 100 or 200 μM sphingosine induced a slight and transient increase in [Ca²⁺]_i. The addition of LaCl₃ to the medium resulted in the same effect as chelation of extracellular Ca²⁺. When cells were incubated in low Ca²⁺ medium containing sphingosine, and extracellular Ca²⁺ was subsequently added, a rapid increase in [Ca²⁺]_i depending on the concentration of sphingosine was shown. In low Ca²⁺ medium, a slight increase in [Ca²⁺]_i induced by high concentrations of sphingosine was not shown after the transient increase in [Ca²⁺]_i elicited by methacholine. Inhibitors of protein kinase C, H-7 and K252a, did not mimic the effect of sphingosine on [Ca²⁺]_i. These results suggest that sphingosine stimulates Ca²⁺-influx and further stimulates the release of Ca²⁺ from agonist-sensitive intracellular pools by a mechanism that is independent of protein kinase C.

【 授权许可】

Unknown