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Blood platelet heterogeneity: evidence for two classes of platelets in man and rat
Author(s) -
Behnke O.,
Forer A.
Publication year - 1993
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1993.tb03147.x
Subject(s) - platelet , biochemistry , gtp' , population , adenosine diphosphate , thrombin , pyrophosphate , ristocetin , chemistry , megakaryocyte , biology , enzyme , microbiology and biotechnology , immunology , medicine , platelet aggregation , environmental health , stem cell , haematopoiesis
Summary. The platelet population of man and rat can be divided into two classes of about equal size on the basis of presence/absence of an acid phosphatase which acts on paranitrophenylphosphate (a PNPase), at pH 5. The cytochemical reaction product is in the platelet cytoplasmic matrix, without apparent association with organelles or membrane systems. We could not relate differences in staining to differences in function: all cells responded the same to activation by thrombin, ADP, or collagen, in fibrinogen binding to activated platelets, by endocytosis of fluid‐phase tracers, and in internalization of latex particles. With respect to possible physiological substrates for the PNP‐ase, there was no reaction product from β‐glycerophosphate, AMP, ADP, ATP, GTP, CMP, IMP, cAMP, creatine phosphate, and inositol phosphates, and the enzyme was not inhibited by 40 m m lithium. There was reaction product from tyrosine phosphate suggesting that the physiological substrate for PNP‐ase is tyrosine phosphate. In rat bone marrow, megakaryocytes also were of two classes, PNPase positive and PNPase negative, suggesting that different classes of platelets arise from different classes of megakaryocytes.