Shear stress-induced aggregation of oxidized platelets.
Although shear stress-induced platelet aggregation (SIPA) has been noted, the shear stress-induced aggregation of oxidized platelets (SIOPA) has not been investigated. To investigate SIOPA, small quantity of hemoglobin (Hb) solution was first added to plasma to induce oxidation stress of platelets and then the plasma was sheared by a cone/plate viscometer at shear stress of 66 dyn/cm2. In addition, to investigate the change in expression of the membrane receptors of glycoprotein Ib (GpIb) for oxidized platelets, mean fluorescence intensity (MFI) for those platelets was detected by flow cytometric technique. The results showed that the level of the oxidation stress of platelets, as presented in malondialdehyde (MDA) values, was well correlated with the quantities of added Hb. Moreover, the aggregation of SIOPA corresponded with the levels of oxidation stress of platelets. Platelets pretreated with aspirin could only partially reduce the aggregation of SIOPA. Similarly, aspirin pretreatment could partially reduce the lowering of MFI value that indicated downexpression of GpIb receptors. Furthermore, the aggregations of SIOPA corresponded with the lowered percentage of those MFI values for studied cases. We thereby suggested that the aggregation of SIOPA is related to both the level of oxidation stress and the downexpression of GpIb receptors for oxidized platelets.
Chung
Tze-Wen
TW
Department of Biomedical Engineering, Chung-Yuan Christian University, Chung-Li, Taiwan, ROC. twchung@mail.be.cycu.edu.tw
Tyan
Yu-Chang
YC
Hsieh
Jui-Hsiang
JH
Wang
Shoei-Shen
SS
Chu
Shu-Hsun
SH
D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology*; D013314:Stress, Mechanical
D006454:Hemoglobins; D008315:Malondialdehyde; D001241:Aspirin