Introduction: We have improved a rodent vascular permeability measurement method employing fluorescent dye-labeled bovine serum albumin.
Methods: The incubation duration for direct fluorescent detection of skin injected with an inflammatory agent was decided based on regression curve parameters with the correlation coefficient obtained from the least squares method.
Results: A suitable incubation time was determined to be 2-6 h. The recovery of FITC-BSA from the skin sample was very good, and the correlation coefficient of the linear regression curve was .99. The linear relation between the previous dye extraction method using brilliant blue 6B and the new and improved fluorescence method was very high. In mice, histamine-induced serum exudation in the back skin increased from 0.31 to 1.25 microg/site in a dose-dependent manner and reached a plateau at 1.25-2.5 microg/site. The serum exudation caused by histamine increased to 10 microg/site and almost reached a plateau at 10-40 microg/site in rats. The time required for the measurement of fluorescence intensity was very short because a microplate reader was used as the measurement apparatus.
Conclusion: The improved method is easy to use and sensitive and does not necessitate extraction of dye from the skin.