A Defect in Collagen Receptor-Ca2+ Signaling System in Platelets from Cattle with Chediak-Higashi Syndrome

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Abstract

Decreased platelet aggregation to collagen is a cause for bleeding diathesis of###Chediak-Higashi syndrome (CHS). We investigated whether the collagen receptor -###Ca2+ signaling system was impaired in platelets from cattle affected with CHS.###Collagen-induced increase in cytosolic Ca2+ ([Ca2+]i) was depressed in CHS platelets,###which was accompanied by a decrease in production of inositol 1,4,5-trisphosphate.###Under the condition that influences of endogenous arachidonic acid metabolites and###ADP were excluded, convulxin or collagen-related peptide, which are specific agonists###for the collagen receptor GPVI, increased [Ca2+]i similarly in normal and CHS platelets.###In contrast, rhodocytin, which was proposed to activate another collagen receptor###GPIa/IIa, increased [Ca2+]i much less in CHS platelets than in normal ones.###Cytochalasin D, an actin polymerization inhibitor, depressed the response to collagen or###rhodocytin but not that to convulxin. Adhesion of CHS platelets to acid soluble type I###collagen, which was mediated by GPIa/IIa, was similar to that of normal platelets.###These results suggest that a defect in rhodocytin-sensitive pathway is responsible for###depression of response to collagen in CHS platelets. It remains to be determined what###receptor is associated with the mechanism.

Journal

  • Thrombosis and Haemostasis

    Thrombosis and Haemostasis 87(2), 334-341, 2002

    Schattauer

Codes

  • NII Article ID (NAID)
    120001157405
  • NII NACSIS-CAT ID (NCID)
    AA00863137
  • Text Lang
    ENG
  • Article Type
    journal article
  • ISSN
    0340-6245
  • Data Source
    IR 
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