Affiliations: [a] Department of Mechanical Systems Engineering, Tokyo City University, Tokyo, Japan
| [b] Department of Medical Engineering, Tokyo City University, Tokyo, Japan
Correspondence:
[*]
Address for correspondence: Kenjiro Shimano, Tokyo City University 1-28-1 Tamazutsumi, Setagaya, Tokyo 158-8557, Japan. Tel.: +81 3 5707 0104; Fax: +81 3 5707 1180; E-mail: [email protected].
Abstract: Background:Prediction of thrombus formation at intact arterial walls under low shear flow conditions is clinically important particularly for better prognoses of embolisation in cerebral aneurysms. Although a new mathematical model for this purpose is necessary, little quantitative information has been known about platelet adhesion to intact endothelial cells. Objective:The objective of this study is to measure the number of platelets adhering to intact endothelial cells with a focus upon the influence of the shear rate. Methods:
Endothelial cells disseminated in μ-slides were exposed to swine whole blood at different shear rates. Adenosine diphosphate (ADP) was used as an agonist. Adherent platelets were counted by means of scanning electron microscopy.
Results:
At an ADP concentration of 1 µM, 20.8 ± 3.1 platelets per 900 µm2 were observed after 30-minute perfusion at a shear rate of 0.8 s−1 whereas only 3.0 ± 1.4 per 900 µm2 at 16.8 s−1.
Conclusions:
The number of adherent platelets is determined by a balance between the shear and the degree of stimulation by the agonist. At an ADP concentration of 1 µM, a limit to the shear rate at which platelets can adhere to intact endothelial cells is considered to be slightly higher than 16.8 s−1.
