Analysis of platelet inhibition function by measuring phosphorylation of the intracellular cytoskeleton protein VASP in whole blood over time

The state of platelets may depend on the time since blood draw, primarily because of the presence of short-lived inhibitors of platelet activation in circulation. In this work, we analyzed the phosphorylation of vasodilator-stimulated phosphoprotein (VASP), which correlates with platelet inhibition, over time using flow cytometry. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. We investigated VASP phosphorylation in platelets in whole blood immediately after the blood was collected and 60 minutes later. As a positive control, we used platelet function inhibition by prostaglandin E1. As a result, it was found that the level of VASP phosphorylation in platelets in whole blood did not differ significantly in samples taken immediately after the blood draw and 60 minutes later, however it was markedly increased with platelet inhibition by prostaglandin E1. Our results suggest that the state of platelets does not change significantly within 60 minutes after the blood draw.