Effects of different anticoagulants on human platelet size distribution and serotonin (5-HT) induced shape change and uptake kinetics.
The effect of collecting blood with disodium ethylene diamine tetraacetate (EDTA), citrate (NAC) or acid sodium citrate-dextrose (ACD) as anticoagulants on platelet count and size distribution was investigated. No difference between the three preparations regarding platelet count was found in whole blood. Preparation of platelet-rich plasma (PRP) significantly reduced the platelet count in NAC-PRP (p less than 0.01) to a value of 288 X 10(9)/l compared to those of 365 X 10(9)/l and 368 X 10(9)/l in EDTA and ACD blood respectively. A significant shift in the platelet size in EDTA-PRP towards larger cell volumes was observed. There were no differences in the size distribution pattern between NAC-PRP and ACD-PRP in spite of the differences in platelet count. Platelet 5-HT uptake kinetics in EDTA-PRP showed a 50 per cent reduction in both Km and Vmax compared to that in ACD-PRP. The study shows that the receptor mediating 5-HT induced shape change has a direct opposite pH dependence than that of the 5-HT carrier. Interference of receptor-mediated responses in 5-HT uptake studies in human platelets is clearly minimized at a lowered pH. The finding is probably of importance in disorders associated with platelet hyperaggregability.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000925:Anticoagulants / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002412:Cations / Q000097:blood; D019343:Citric Acid; D004492:Edetic Acid / Q000494:pharmacology; D005947:Glucose / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007099:Imipramine / Q000494:pharmacology; D007700:Kinetics; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism* / Q000494:pharmacology
D000925:Anticoagulants; D002412:Cations; D011985:Receptors, Serotonin; C002113:acid citrate dextrose; D019343:Citric Acid; D012701:Serotonin; D000244:Adenosine Diphosphate; D004492:Edetic Acid; D005947:Glucose; D007099:Imipramine