A simple fluorescent method for simultaneous determination of aortic permeability to horseradish peroxidase and bovine serum albumin.

Differences in regional aortic net uptake of bovine serum albumin (BSA) and horseradish peroxidase (HP) have been examined by means of conjugation of these molecules to the fluorescent protein tracers fluorescein isothiocyanate (FITC) and lissamine rhodamine B (RB200). Using male Wistar rats, uptake of FITC-BSA under steady state conditions in the ascending aorta and aortic arch (14 +/- 2 micrograms/mg aorta) is significantly higher (p less than 0.05) than that of either the upper, middle, or lower third of the thoracic aorta (10 +/- 1 mu, 9 +/- 1 mu, and 8 +/- 1 micrograms/mg, respectively).