Secretory phospholipase A2 is released from pancreatic β-cells and stimulates insulin secretion via inhibition of ATP-dependent K+ channels

被引：18

作者：

Juhl, K ^{[1
]}

Efanov, AM ^{[1
]}

Olsen, HL ^{[1
]}

Gromada, J ^{[1
]}

机构：

[1] Novo Nordisk AS, Lab Islet Cell Physiol, DK-2880 Bagsvaerd, Denmark

来源：

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | 2003年 / 310卷 / 02期

关键词：

secretory phosholipase A(2); islets of Langerhans; insulin secretion; arachidonic acid; lysophosphatidylcholine;

D O I：

10.1016/j.bbrc.2003.09.018

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The release of sPLA, from single mouse pancreatic beta-cells was monitored using a fluorescent substrate of the enzyme incorporated in the outer leaflet of the plasma membrane. Stimulation of beta-cells with agents that increased cytosolic free Ca2+ concentration ([Ca2+](i)) induced a rapid release of sPLA(2) to the extracellular medium. Exogenous sPLA(2) strongly stimulated insulin secretion in mouse pancreatic islets at both basal and elevated glucose concentrations. The stimulation of insulin secretion by sPLA(2) was mediated via inhibition of ATP-dependent K+ channels and an increase in [Ca2+]i. Measurements of cell capacitance in single beta-cells revealed that sPLA, did not modify depolarisation-induced exocytosis. Our data suggest that a positive feedback regulation of insulin secretion by co-released sPLA(2) is operational in pancreatic beta-cells and point to this enzyme as an autocrine regulator of insulin secretion. (C) 2003 Elsevier Inc. All rights reserved.

引用

页码：274 / 279

页数：6

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