Regulation of platelet cytosolic free calcium by cyclic nucleotides and protein kinase C

FEBS Letters

MacIntyre, D.E.¹  Bushfield, M.¹  Shaw, A.M.¹ 

[1] Department of Pharmacology, University of Glasgow, Glasgow G12 8QQ, Scotland

关键词: Platelet;    Calcium;    Cyclic AMP;    Cyclic GMP;    Phorbol ester;    Protein kinase C;   

DOI  :  10.1016/0014-5793(85)80407-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

PAF elicits a rapid, concentration-dependent elevation of platelet cytosolic free calcium ([Ca_f]), measured by quin2. Elevation of [Ca_f] is transient, and the rate of reversal increases with agonist concentration. Adenylate cyclase stimulants (PGI₂, PGD₂) and 8-bromo cAMP; a guanylate cyclase stimulant (sodium nitroprusside) and 8-bromo cGMP; and a protein kinase C stimulant (phorbol myristate acetate) block the elevation of [Ca_f] induced by PAF, and accelerate its reversal. These results suggest that cAMP, cGMP and 1,2-diacylglycerol (DAG) could act as second messengers to regulate [Ca_f] in platelets. As PAF is known to stimulate platelet phosphoinositide hydrolysis (ergo DAG formation) but fails to elevate platelet cAMP or cGMP, it is proposed that DAG, via activation of protein kinase C, may act as an endogenous modulator of platelet [Ca_f]: an action that contributes to the role of DAG as a bi-directional regulator of platelet reactivity.

【 授权许可】

Unknown