Reduction of heparin binding to and inhibition of platelets by aprotinin

• Published in: The Annals of thoracic surgery Vol. 55; no. 5; pp. 1175 - 1179
• Main Authors: John, Lindsay C.H., Rees, Gareth M., Kovacs, Iren B.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-05-1993; Elsevier Science
• Subjects: Adenosine Diphosphate - pharmacology; Aprotinin - pharmacology; Biological and medical sciences; Blood Coagulation - drug effects; Blood Platelets - drug effects; Blood Platelets - metabolism; Blood. Blood coagulation. Reticuloendothelial system; Female; Hemostasis - drug effects; Heparin - metabolism; Heparin - pharmacology; Heparin Antagonists - pharmacology; Humans; Male; Medical sciences; Middle Aged; Pharmacology. Drug treatments; Platelet Activation - drug effects; Platelet Count; Time Factors; Tritium; Human; Hemostasis; Interaction; Platelet function; Heparin; Mechanism of action; Protection; In vitro; Biological activity
• ISSN: 0003-4975; 1552-6259
• DOI: 10.1016/0003-4975(93)90029-H

The direct effect of aprotinin on in vitro platelet function was assessed by hemostatometry (n = 10). No significant enhancement was demonstrated. However, aprotinin reduced platelet inhibition secondary to heparin. Hemostatometry demonstrated a significant preservation of in vitro platelet function (n = 25) (
p = 0.04), which was particularly marked (
p = 0.003) in the subgroup (n = 7) demonstrating a severe inhibition of platelet function with heparin. Aprotinin significantly reduced the binding of tritium-labeled heparin to both nonactivated (n = 25) (
p = 0.004) and activated platelets (n = 25) (
p < 0.0001). We conclude that interference with heparininduced inhibition of platelet function by aprotinin may be one of its hemostatic actions in cardiac surgery. This effect is probably secondary to aprotinin reducing binding of heparin in platelets.