Stimulation of Ca2+ efflux from fura‐2‐loaded platelets activated by thrombin or phorbol myristate acetate

FEBS Letters

Sage, S.O.²  Rink, T.J.¹  Pollock, W.K.³ 

[1] Smith Kline and French Research Ltd, The Frythe, Welwyn, England;Physiological Laboratory,University of Cambridge, Cambridge, England;Biochemistry Department, AFRC, IAP, Babraham, Cambridge, England

关键词: Platelet;    Ca2+;    Fura-2;    Ca2+ efflux;    Protein kinase C;   

DOI  :  10.1016/0014-5793(87)81322-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We investigated the restoration of [Ca²⁺]_i in fura-2-loaded human platelets following discharge of internal Ca²⁺ stores in the absence of external Ca²⁺. After stimulation by thrombin [Ca²⁺]_i returned from a peak level of 0.6 μM to resting levels within 4 min. When ionomycin discharged the internal stores the recovery was slower with [Ca²⁺]_i still elevated at around 0.5 μM after 5 min. Thrombin added shortly after ionomycin could accelerate the recovery of [Ca²⁺]_i and restore resting levels within 5 min, an effect that was mimicked by phorbol-12-myristate-13-acetate (PMA). Since the continued presence of ionomycin precluded reuptake into the internal stores we conclude that thrombin and PMA stimulate Ca²⁺ efflux, perhaps via protein kinase C actions on a plasma membrane Ca²⁺ pump.

【 授权许可】

Unknown