The Sensitivity of Cochlear Albino Melanocytes to Horseradish Peroxidase

Abstract

The effects of low concentrations (0.5%-0.0005%) of HRP and varying postperfusion survival times (5.5 hours- 15 seconds) on cochlear albino melano-cytes were studied by light and electron microscopy. Approximately 50 μl of differing concentrations of HRP dissolved in artificial perilymph were perfused through the perilymphatic space in 32 albino guinea pigs. Tissues were subsequently treated histochemically to demonstrate HRP reaction product. The results indicate that concentrations of HRP>0.0005 % in combination with postperfusion survival times >1 hour bring about acute and selective injury to the albino melanocytes; cytoplasmic vacuolization and rupture of cell membranes occurred. The structural integrity of the albino melanocytes appeared unaltered when exposed to 0.0005% concentrations of HRP for ≤1 hour. An apparently non-toxic 0.0005 % concentration of HRP may provide a means of labeling cochlear melanocytes when the effects of other substances on the cells are investigated.