Comparative cytochemical and stereological studies on blood platelets from five mammalian species
Abstract
The present paper reports on comparative quantitative analyses of the thrombocytic content of adenine nucleotides (ATP, ADP; firefly luciferase technique), platelet-specific proteins (platelet factor 4, β-thromboglobulin; radioimmunoassay), and a lysosomal enzyme (β-glucuronidase; Fishman- and Szasz-technique), measured with the platelets from man, dog, pig, sheep, and cat. These data are faced with the results from morphometric and stereologic investigations (e.g. determination of volume- and numerical density) obtained from electronmicrographs of subcellular platelet structures, such as alpha-granules and dense bodies. Both organelles are known to be specific intrathrombocytic storage sites of the above mentioned substances.
Remarkable differences are described to exist between the platelets from the five species. An evident correlation, however, persisting between the thrombocytochemical and structural parameters is missing on the whole. Therefore it is pointed out that, at the moment, quantitative statements cannot be made upon the thrombocytic content of stored substances from the geometry of the platelet storage granules, alone.