Ultrastructural morphometric observations on serial sectioned human blood platelet subpopulations
Duyvené de Wit, L.J.; Badenhorst, P.N.; Heyns, A.D.
European Journal of Cell Biology 43(3): 408-411
1987
ISSN/ISBN: 0171-9335 PMID: 3622527 Document Number: 301684
The relationships between the volume of human platelets and their cytoplasmic organelles were studied by morphometric analysis. Platelets were separated into four density-dependent subpopulations on an arabino-galctan gradient. In vitro activation of platelets was effectively prevented by maintaining them at a constant ambient temperature of 37.degree. C. Serial sections were cut through platelets, morphometrically analyzed and the platelets reconstructed. The volumes of the individual platelets and their constituent granules, mitochondria and open canalicular systems (OCS) were calculated. Individual organelles were counted. The mean volumes of the platelets of the subpopulations decreased significantly as density decreased (p = 0.01). Also, as the density of platelets decreased, there was a decrease in the mean unit volume of their granules (p = 0.003). In contrast, independent of platelet volume their granules Cp = 0.003). In contrast, independent of platelet volume or density, the OCS occupies about 10% of the platelet volume. These findings indicate that it is possible to prevent in vitro platelet activation by maintaining their environment at 37.degree. C. Our study confirms the direct relationships between platelet volume and density; and platelet density and granule content. There is no ready explanation for the constant relationship between platelet volume and that of the OCS.