Hypothermia of 8 Degrees C Protects Cultured Retinal Pigment Epithelial Cells and Retinal Ganglion Cells Against Trypan Blue Toxicity

Abstract

Purpose: : To determine whether trypan blue (TB) is toxic to cultured human retinal pigment epithelial (ARPE–19) cells and rat retinal ganglion cells (RGC–5), and whether hypothermia of 8°C can protect these cells against the TB toxicity.

Methods: : ARPE–19 cells and RGC–5 were cultured and exposed to balanced salt solution (BSS) as control, and to 0.05% and 0.5% TB in BSS at 37°C and 8°C for 1 minute. The percentage of ARPE–19 cells and RGC–5 that survived in the experimental groups relative to the control group was determined by resazurin 1 day after the exposure.

Results: : TB induced a statistically significant decrease in the percentage of RPE cell surviving at 0.5% TB at 37°C (P <0.01). The percentage of surviving ARPE–19 cells in 0.05% TB at both 37°C and 8°C, and in 0.5% TB at 8°C was not significantly different from that of controls. On the other hand, TB induced a statistically significant decrease in the percentage of RGC–5 surviving at all conditions except for 0.05% TB at 8°C (0.05% 37°C; P <0.05, 0.5% 37°C and 8°C; P <0.01).

Conclusions: : These results indicate that TB is toxic to ARPE–19 cells and RGC–5 in culture, but reducing the temperature to 8°C has a protective effect against the TB toxicity.

Keywords: drug toxicity/drug effects • ganglion cells • retinal pigment epithelium