The effects of aprotonin on platelets in vitro using whole blood flow cytometry.
We sought to evaluate the effects of aprotinin on the number and function of the platelet glycoprotein (GP) IIb-IIIa receptor and on the expression of P-selectin in vitro in order to gain insight into the potential mechanisms involved in the platelet-protective action of aprotinin during cardiopulmonary bypass. Aprotinin at 50 to 200 kallikrein inhibiting units/mL decreased the expression of activated GP IIb-IIIa complex in response to adenosine diphosphate or thrombin receptor activator peptide 6 in a dose-dependent manner in both citrated and heparinized whole blood experiments. Aprotinin inhibited adenosine diphosphate-induced platelet aggregation, but it exhibited no effect on the expression of GP IIIa and P-selectin. These results indicate that aprotinin interferes with the platelet fibrinogen receptor function during pharmacological activation. Reduced aggregability and platelet adhesion to fibrinogen adsorbed to synthetic surfaces in the presence of aprotinin may prevent platelet consumption during clinical cardiopulmonary bypass. This in vitro study demonstrates that aprotinin decreases the agonist-induced expression of activated GP IIb-IIIa receptors that play a major role in platelet aggregation and adhesion to biomaterial surfaces.


CONCLUSIONS
This in vitro study demonstrates that aprotinin decreases the agonist-induced expression of activated glycoprotein IIb-IIIa receptors that play a major role in platelet aggregation and adhesion to biomaterial surfaces.
Kozek-Langenecker
S A
SA
Department of Anesthesiology, University of Vienna, School of Medicine, Austria. sibylle.kozek-langenecker@univie.ac.at
Mohammad
S F
SF
Masaki
T
T
Green
W
W
Kamerath
C
C
Cheung
A K
AK
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000378:metabolism; D007611:Aprotinin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D039661:Integrin beta3; D010446:Peptide Fragments / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D018179:Receptors, Thrombin / Q000187:drug effects / Q000502:physiology; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D039661:Integrin beta3; D010446:Peptide Fragments; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D010980:Platelet Membrane Glycoproteins; D018179:Receptors, Thrombin; D015842:Serine Proteinase Inhibitors; C082835:thrombin receptor peptide (42-47); D000244:Adenosine Diphosphate; D007611:Aprotinin