A major role for P2X1 receptors in the early collagen-evoked intracellular Ca2+ responses of human platelets

C. Y. Eleanor Fung; Charles A. Brearley; Richard W. Farndale; Martyn P. Mahaut-Smith

doi:10.1160/TH04-11-0732

Thrombosis and Haemostasis, Table of Contents

Thromb Haemost 2005; 94(01): 37-40
DOI: 10.1160/TH04-11-0732

Rapid and Short Communication

Schattauer GmbH

A major role for P2X₁ receptors in the early collagen-evoked intracellular Ca²⁺ responses of human platelets

C. Y. Eleanor Fung

¹Department of Physiology, University of Cambridge, Cambridge, UK

,

Charles A. Brearley

³School of Biological Sciences, University of East Anglia, Norwich, UK

,

Richard W. Farndale

²Department of Biochemistry, University of Cambridge, Cambridge, UK

,

Martyn P. Mahaut-Smith

¹Department of Physiology, University of Cambridge, Cambridge, UK

› Author Affiliations

Abstract

Summary

In the platelet, ATP-gated P2X₁ receptors have been reported to amplify functional responses to collagen, however the relative importance of early Ca²⁺ mobilisation events is unknown. We now report that selective desensitisation of P2X₁ receptor activity leads to a major reduction in the initial intracellular Ca²⁺ responses to a wide range of collagen concentrations (0.25–2 μg ml^-1). Peak [Ca²⁺]_i increases were reduced to 8.5 and 55% of control, and the maximum rate of rise was reduced to 12 and 33% of control, at low and high collagen concentrations, respectively. This P2X₁-dependent acceleration and enhancement of collagen-stimulated Ca²⁺ responses was not observed in the absence of extracellular Ca²⁺. These results demonstrate a major role for ATP-gated Ca²⁺ influx in the early collagen-evoked Ca²⁺ signals and can at least partly explain the important contribution of P2X₁ receptors to arterial thrombosis.

Keywords

P2X₁ - ATP - collagen - Ca²⁺ - thrombosis

Full Text

References

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