Der Einfluss von laminaren Strömungen und Sekundärströmungen im Taylor-Couette-System auf die Thrombozyten

In vivo and in vitro laminar flow often occurs in combination with secondary flow like vortical flow patterns. Sudden changes in blood vessel or tube size e.g. in extracorporeal circulation generate such vortices. So far platelet activation mechanism in these regions are merely investigated. Therefore a Taylor-Couette flow model was developed to generate defined blood flow either with laminar or vortical flow pattern at the same shear rate. Platelet adhesion and activation were investigated as markers for thrombogenicity. Adhesion of resting platelets is regarded as the first step to shape change, aggregation and secretion of the granule components. Additionally various metabolic and functional changes in platelets, like activation of surface receptors and changes in the orientation of phospholipids in the plasma membrane occur. The level of platelet activation depends on the type of stimulation. In the Taylor-Couette system different types of stimulation depending on flow condition and contact to biomaterial surfaces were generated. Results add up to a complex relationship between blood flow and platelet activation. Platelet adhesion on surface and PF4-release is significantly higher applying pure laminar shear flow compared to flow with stable vortices. Due of the higher adhesion the local concentration of soluble agonists is enhanced. Depending on the two flow modes adherent platelets are deposited in different patterns. At laminar flow platelets are uniformly distributed. In the presence of secondary flow platelets form adherent aggregates. Secondary flow with formation of stable vortices increases fibrinogen receptor activation and aggregate formation of the platelets. Most probably this preactivation of circulating platelets results in thrombus formation or embolisation in other geometrical configurations and flow conditions downstream.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2002

Author dc:creator

• Körfer, Sabine

Contributors dc:contributor

• Mottaghy, Khosrow

• info:eu-repo/classification/ddc/610
• Medizin

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-119107%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:57037