A ROLE FOR PROTEINS IN AQUEOUS OUTFLOW RESISTANCE

Title A ROLE FOR PROTEINS IN AQUEOUS OUTFLOW RESISTANCE
Author, Co-Author Thomas Freddo, Haiyan Gong, Mark Johnson
Topic
Year
1992
Day
Sunday
Program Number
1:00 pm
Room
Scotland B
Affiliation
Abstract We have recently demonstrated that the majority of the plasma-derived protein in normal aqueous humor (AH) enters the anterior chamber directly, through the root of the iris rather than from the posterior chamber (Freddo, et al. 1990; Barsotti, et al, 1991). The proximity of this entry point to the aqueous outflow pathways raised the possibility that the amount of protein entering the outflow pathways might be much higher than previously suspected based upon protein assays of anterior chamber AH. To better understand the role that the additional proteins might have on aqueous outflow resistance, we used monoclonal antibodies to bovine serum albumin (with indirect immuno-gold and silver enhancement) to localize albumin (AL) in the outflow pathways of bovine and human eyes. AL was found in ample supply in the meshwork with the highest concentrations in the juxtacanalicular region. Preadsorption of the primary antibody gave negative results. To determine if the well-documented but poorly understood "wash-out" effect seen in perfusion studies might be due to wash-out of proteins, perfusions were completed on enucleated bovine eyes using perfusion fluid containing bovine serum in concentrations from 0-15%. At lower concentrations, "wash-out" occurred and this correlated with a loss of the previously documented AL staining. Serum concentrations in the range of 12% eliminated the "wash-out" effect. The staining reaction for AL appeared the same as seen in unperfused eyes suggesting a central role for proteins in the "wash-out" effect and possibly in normal outflow resistance.
Affiliation of Co-Authors
Outline