Determination of total protein concentration and viscosity of synovial fluid from the tibiotarsal joints of horses.

The research involved measuring the viscosity of synovial fluid from 29 healthy horses’ joints using a microviscosimeter and determining the total protein concentration in the fluid using a refractometer. The resulting data provides a normal range that can be used for comparing results of synovial fluid analysis from horses with joint disease.

Research Methodology

• The researchers collected synovial fluid (SF) from the tibiotarsal joints of 29 clinically normal horses.
• They used a rotational cone and plate microviscosimeter, a device used to measure the viscosity of fluid by rotating a cone in the fluid and determining the resistance to the motion, to determine the viscosity of the SF.
• The total protein concentration in the SF of the 29 horses was measured using a refractometer, which uses the principle of refractive index to measure solute concentration in a solution.
• They further used the Coomassie brilliant blue test to determine the total protein concentration in SF for 15 of the horses. This dye-binding assay allows an accurate protein concentration to be determined.

Results

• The total protein concentration measured using the refractometer was less than 2.5 g/dl.
• When the Coomassie brilliant blue test was used, the average protein concentration was found to be 1,088 mg/dl.
• The SF viscosity values were determined at different spindle speeds (60, 30, 12, 6, 3, and 1.5 rpm). Exact measurements for each speed were provided, showing increased viscosity with decreasing rpm and shear rate.
• The viscosity curve for each horse fit the asymptotic curve, which increases slowly over time towards a limit but never actually reaches it.

Conclusion

• The researchers concluded that the rotational cone and plate microviscosimeter was an accurate instrument for measuring SF viscosity at multiple rpm or shear rates in horses.
• The collected data on the protein concentration and viscosity of SF from clinically normal horses provides baseline values. This will assist in comparison and evaluation when examining horses with joint disease in future studies.