Platelet heterogeneity based on lactic dehydrogenase activity.
Mean lactic dehydrogenase (LDH) activity of human platelets is about 5 nU/platelet; expressed on a cell volume basis, it is 0.5 nU/fl. Platelet separation by means of centrifugation on a Percoll discontinuous gradient gives different subpopulations with a clear-cut change of LDH at a mean platelet volume (MPV) of about 6 fl. The LDH content of platelets with a MPV > 6 fl is constant (about 0.5 nU/fl), while that of small platelets (3 < MPV < 6 fl) is inversely correlated with the MPV and reaches a value of 1.5-2.0 nU/fl. Because small platelets are granule-depleted, we suggest that platelet LDH activity be considered as an in vivo activation index.
De Sole
P
P
Istituto di Fisiologia Umana, Servizio di Chimica Clinica, Catholic University, Rome, Italy.
Zappacosta
B
B
D000328:Adult; D001792:Blood Platelets / Q000166:cytology / Q000201:enzymology*; D002469:Cell Separation; D048429:Cell Size; D002499:Centrifugation, Density Gradient; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood*
D007770:L-Lactate Dehydrogenase