A colorimetric assay for releasable plasminogen activator

Area of Science:

• Biochemistry
• Vascular Biology
• Clinical Diagnostics

Background:

• Plasminogen activator is crucial for fibrinolysis.
• Measuring its release from blood vessels is important for understanding thromboembolic disease.
• Existing assays have limitations in speed and complexity.

Purpose of the Study:

• To describe a novel equilibrium assay for measuring plasminogen activator release.
• To validate this new assay against a previously established method.
• To evaluate the assay's performance in individuals without thromboembolic disease.

Main Methods:

• Developed a colorimetric assay using the chromogenic substrate D-Val-Leu-Lys-p-nitroanilide.
• Collected plasma euglobulin fractions from 125 healthy individuals before and after venous occlusion.
• Measured plasmin generation and compared results with a radiocasein assay in 24 subjects.

Main Results:

• The new colorimetric assay demonstrated high correlation (r=0.97) with the radiocasein assay.
• The colorimetric assay requires shorter incubation times (6 hours vs. 16 hours).
• Eliminates the need for radioactive substrate preparation and quantification.

Conclusions:

• The described colorimetric assay is a reliable and efficient method for quantifying releasable plasminogen activator.
• This assay offers significant advantages in terms of speed and simplicity.
• It provides a valuable tool for research and clinical assessment of vascular function.