Summary
Various tests were evaluated for their capacity to differentiate between platelet
suspensions with different degrees of cell damage. Those suspensions were prepared
by simultaneous isolation of platelets from the same platelet-rich plasma (PRP) using
the following procedures:
1. centrifugation at 4°C with EDTA
2. gel filtration in Tangen’s buffer
3. gel filtration in Ca2+-free Tyrode’s solution
4. gel filtration in Ca2+-free Tyrode followed by dehydration against polyethylene glycol 20,000 and
5. albumin density gradient centrifugation.
In these suspensions and in the original PRP the following parameters were studied:
1. morphology; 2. aggregability upon ADP addition; 3. platelet factor 3 availability;
4. uptake of 14C-serotonin and 3H-adenine; 5. metabolism of 3H-adenine and adenylate energy charge; 6. endogenous total ATP, ADP and serotonin
and 7. lactate dehydrogenase (LDH) activity.
Quantitation of pseudopod formation in the light or electron microscope and log dose
response studies for ADP-induced aggregation proved to be the most sensitive and reproducible
of the tests studied. Additional information could be obtained from measurement of
the 3H-label in the ATP and hypoxanthine-inosine fractions and calculation of the adenylate
energy charge. Determination of platelet factor 3 availability or uptake studies of
14C-serotonin and 3H-adenine were less suitable for discriminating between cell suspensions. Data for
total ATP and serotonin concentrations and LDH activity differed between the cell
suspensions but instead of detecting various degrees of cell damage they reflected
alterations in platelet population caused by the isolation procedures.
