Semin Thromb Hemost 2000; Volume 26(Number 01): 043-046
DOI: 10.1055/s-2000-9802
Copyright © 2000 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel.: +1(212) 584-4663)

Pathogenesis of a Bleeding Disorder Characterized by Platelet Unresponsiveness to Thromboxane A2

Ichiro Fuse, Wataru Higuchi, Yoshifusa Aizawa
  • First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
Further Information

Publication History

Publication Date:
31 December 2000 (online)

 

ABSTRACT

A platelet disorder characterized by the absence of thromboxane A2 (TXA2)-induced platelet aggregation is a new clinical entity of platelet dysfunction. The platelets of three patients had the ability to bind exogenous TXA2, but synthetic TXA2 mimetic-induced postreceptor biochemical events, such as IP3 formation, Ca2+ mobilization, phosphatidic acid formation, and GTPase activities, were selectively defective, suggesting impaired coupling between the TXA2 receptor and phospholipase C activation. Gene analysis of the TXA2 receptor showed a substitution of Leu for Arg60 in the first cytoplasmic loop in all patients, and this mutation seemed to be responsible for this platelet disorder.

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