Combined cytochemical detection of Müller-cell-specific enzyme activity and permeability tracers

A combination of cytochemical methods in one tissue section was studied in order to detect the contribution of Müller cells to the blood-ocular barrier. Applications are shown for the detection of Müller cells and peroxidatic enzymes. The following advantages of the present method were demonstrated: superior sensitivity of glucose-6-phosphatase (G6Pase) activity, which allows the detection of these cells even in the coagulated retina. The reaction products showed no deleterious change after a subsequent reaction. These factors, and the contrasting reaction products of G6Pase and the enzymatic tracers (especially those of horseradish peroxidase) allow the distinction of Müller cells and the functional barrier site.