Stimulation of calcium influx and platelet activation by canatoxin: Methoxyverapamil inhibition and downregulation by cGMP

被引：25

作者：

Ghazaleh, FA ^{[1
]}

Francischetti, IMB ^{[1
]}

Gombarovits, MEC ^{[1
]}

Carlini, CR ^{[1
]}

机构：

[1] UNIV FED RIO DE JANEIRO, CCS, ICB, DEPT BIOCHEM, BR-21941590 RIO DE JANEIRO, BRAZIL

来源：

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS | 1997年 / 339卷 / 02期

关键词：

canatoxin; platelet; calcium; cGMP;

D O I：

10.1006/abbi.1997.9898

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：

Canatoxin (CNTX), a toxic protein isolated from seeds of Canavalia ensiformis, induces Ca2+ influx across the platelet plasma membrane, mobilization of arachidonic acid mediated by phospholipase A,, ATP secretion, and platelet aggregation. All these events depend on the presence of extracellular Ca2+ and are blocked by methoxyverapamil, a calcium-channel blocker. CNTX does not activate phospholipase C, and the intracellular calcium mobilization mediated by IP3 does not play a role in platelet activation by this toxin. Preincubation of rabbit platelets with 8-Br-cGMP inhibited the CNTX-evoked calcium influx, arachidonate release, ATP secretion, and cell aggregation. Our data suggest that the calcium influx is a prior step on platelet activation by CNTX, being modulated by cGMP. (C) 1997 Academic Press.

引用

页码：362 / 367

页数：6

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