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Platelet activation is reversible and dependent on the shear stress‐exposure time integral
Author(s) -
Rubenstein David A,
Yin Wei
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.593.3
Subject(s) - platelet , shear stress , platelet activation , prothrombinase , chemistry , shear (geology) , annexin , biophysics , shear rate , thrombin , medicine , materials science , composite material , biochemistry , apoptosis , biology , viscosity
Our goal was to determine whether platelets have a memory for shear induced activation and if this is reversible. During cardiovascular diseases, such as atherosclerosis, platelets are subjected to complex pathological shear stress waveforms at particular vascular locations. Platelets may pass this location every circuit inducing a predisposition towards activation. We hypothesized that platelet activation was governed by the shear stress‐exposure time and not the absolute shear stress level. To test this, platelets were exposed to tailored shear stress waveforms to examine if platelets remember past shear stress histories. Activation was quantified with a prothrombinase assay, flow cytometry and aggregometry (agonized with TRAP 6 ). Our prothrombinase assay depends on FVa and PS expression. To verify this assay and aggregation, CD62P, Annexin V and CD41/61 expression was measured. Platelet activation was waveform independent, if the shear stress‐exposure time was the same. This was true even for platelets subjected to supra‐critical shear stress levels (Hellum's curve). With increasing shear stress‐exposure time, activation was enhanced. Platelets that were subjected to a supra‐critical shear stress early were not more susceptible to subsequent shear exposures. Therefore, platelet activation is reversible and dependent on the shear stress‐exposure time and not the absolute value of shear stress.