Investigations of Platelet Function in Whole Blood with BAPA as Anticoagulant

Background: Citrate anticoagulation of blood results in non-physiologically low calcium concentration and rapid deterioration of platelet viability. Benzylsulfonyl-D-Arg-Pro-4-amidinobenzylamide (BAPA) as anticoagulant maintains the physiological calcium level and seems to retain platelet function (PF) over a time period of at least 24 h. We evaluated PF in BAPA-anticoagulated peripheral whole blood (WB) between 0.5 and 30 h after blood collection. Methods: In WB from 21 healthy volunteers (15 women, 6 men, age range 19-57 years) platelet aggregation (PA) was determined by impedance method and ATP release by luminometry. Platelet response was tested by ADP (10 and 20 mu mol/l) and collagen (1 and 2 mu g/ml) between 0.5 and 30 h after blood collection. Results: Parameters of ADP-induced PA showed stable values until 6.5 h after blood collection followed by a significant decline. PA in response to collagen was stable up to 25 h of storage. ATP release induced by collagen displayed a continuous, significant decrease over time. Conclusion: Preservation of platelet response in BAPA-anticoagulated blood depends on the applied agonist showing that collagen-induced PA is more stable compared to ADP known as a weak agonist in WB.