Inhibition of Thrombin‐Induced Platelet Aggregation by Crude and Highly Purified α₁‐Acid Glycoprotein

Abstract

The inhibitory effect of crude and highly purified α1‐acid glycoprotein on thrombin‐induced platelet aggregation were found to be identical.

α1-acid glycoprotein (AGP)-induced platelet shape change involves the Rho/Rho kinase signalling pathway

“…Earlier studies have indicated that AGP indirectly modulates platelet responses. More exactly, it has been shown that the presence of AGP reduces or enhances subsequent agonist-induced platelet aggregation (13)(14)(15), but the molecular mechanism underlying such effects is still largely unknown. In accordance, we observed that AGP slightly reduced aggregation responses following the activation of the thrombin receptor subtype PAR-4.…”

“…Previous research has also suggested that AGP affects cells other than leukocytes, such as platelets and endothelial cells (12)(13)(14), and it has been postulated that AGP can indirectly modulate platelet activation. In particular, experiments have shown that AGP affects agonist-induced platelet aggregation (13)(14)(15), and one of the cited studies linked the anti-aggregation activity of AGP to the terminal sialic acid residues. However, the exact mechanisms by which AGP modulates platelets and contribute to haemostasis and thrombosis have not been revealed.…”