Tumour‐promoting phorbol esters inhibit agonist‐induced phosphatidate formation and Ca2+ flux in human platelets

FEBS Letters

MacIntyre, D.E.¹  Drummond, A.H.¹  McNicol, A.¹ 

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

关键词: Platelet;    Phorbol ester;    Protein kinase C;    Polyphosphoinositide;    Calcium;   

DOI  :  10.1016/0014-5793(85)81063-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Tumour-promoting phorbol esters (phorbol-12-myristate-13-acetate, PMA; phorbol-12,13-dibutyrate, PDBu) but not 4β-phorbol, activate protein kinase C. Using human platelets pre-labelled with quin2 or ³²PO₄ we examined the effects of these compounds on human platelet cytosolic free Ca²⁺ ([Ca²⁺]_j) and on [³²]phosphatidic acid ([³²P]PtdOH). PMA and PDBu, but not 4β-phorbol inhibited thrombin-, PAF- and vasopressin-induced elevation of [Ca²⁺], and [²⁺P]PtdOH formation. It is suggested that protein kinase C may act to terminate the transduction processes that link receptor occupancy to cellular activation.

【 授权许可】

Unknown