Viscoelasticity and structure of blood clots generated in-vitro by rheometry: A comparison between human, horse, rat, and camel.

The research focuses on comparing clot formation and material characteristics of blood clots from human beings, horses, rats, and camels. The study reveals significant differences in viscoelastic properties across these species, providing possible insights for clinical and animal models of blood coagulation.

Research Objective and Methodology

This study aimed at evaluating the differences in clot formation and the material composition of clots from four mammalian species:

• The species under consideration are humans, rats (HL/LE inbred strain), warmblood horses, and dromedary camels.
• The examination of clot structure and characteristics took place across macro, micro, and nano scales using rheometry, scanning electron microscopy (SEM) and small angle x-ray scattering (SAXS).
• With the help of oscillating shear rheometry, the researchers inspected the clot formation until the shear storage modulus G’ reached a plateau formation.
• At this stage, selected clots were prepared for further inspection under scanning electron microscopy to analyze the fibre diameter and fractal dimension.
• Additionally, the team used SAXS to obtain scattering profiles for plasma and whole blood samples.

Key Findings

The research findings displayed significant variation in the viscoelasticity of clots across the species studied:

• Rat and horse clots demonstrated shorter clotting times and higher G’ plateau values compared to human clots, implying higher clotting efficiency.
• Distinct clotting characteristics were observed in camel clots, which showed no G’ plateau formation within the observed timeframe.
• While SEM and SAXS yielded less differential results, they did reveal that rat fibre network appears more convoluted and dense, with increased fractal dimension, suggesting a more intricate clot structure.

Conclusions and Implications

The study’s results suggested evident species-specific differences in clot formation and characteristics:

• Such differences are clinically interesting as they can help in understanding and treating coagulation disorders in diverse species.
• Furthermore, these variations also provide vital insights for constructing animal models of blood coagulation, delivering a more accurate perspective on distinct coagulation mechanisms across species.