Laboratory Rat Thrombi Lose One-Third of Their Stiffness When Exposed to Large Oscillating Shear Stress Amplitudes: Contrasting Behavior to Human Clots

Rats impress by their high platelet count resulting in hypercoagulability, which protects the animals from severe bleeding. However, platelets also import numerous stiff junction points into fibrous system of a clot, enhancing pre-stress fibrin fibers, lowers deformability. Clot deformation is clinically important since large strains are present arterial tree (caused propagation pressure and pulse waves), clot considered “safe” when it can deform over long range strain amplitudes. We tested formation behavior fully formed blood clots laboratory rats at sinusoidal shear stress amplitudes rheometry compared outcomes to human reference data. found that fiber density (by scanning electron microscopy) stiffness rheometry) was pronounced humans differed with sexual dimorphism rat strain. Using our amplitude oscillation (LAOS) protocol, we detected yielded frustrated attempt stiffen instead showing macroscopic stiffening response typical for clots. attribute this appearance multiple microfractures until, finally, few leading fibers uptake load. Rat failed align direction initiate affine deformation. The phenotype differs substantially one, must be research toxicological testing. If meshwork concentrated vivo, parts may break off washed away. homogenously distributed open pores allow penetration plasminogen activators. What occurs vasculature depends on on-site composition.