The influence of pressure on the cell survival and axonal growing in rat retinal ganglion cells in vitro

Abstract

To evaluate the effect of pressures on the changes of purified cultivation of SD suckling rats' retinal ganglion cells (RGC) by a hyperbaric cell culture model and on the expression of neurofilament protein-H (NF-H) in vitro. It was a control experimental study. RGC were purified from twenty SD neonatal rats (postnatal 1 - 3 days) using Thy1.1 antibody and cultured under the pressures of 0, 20, 40, 60, and 80 mm Hg (1 mm Hg = 0.133 kPa) respectively. The growth and survival times of RGC were observed, the numbers of processes of RGC were counted, and the processes measured under the different pressures after 48 h under phase-contrast microscope. The expression of NF-H and its distribution in primary purified RGC was investigated by an immunohistochemical technique and by semi-quantitative statistics analysis using microscopic image-analysis technique. The data was analyzed with SPSS 13.0 software. Difference among groups with One-way ANOVA and ambi-groups with SNK (q test), statistical significance was confirmed as P < 0.05. The purification rate of RGC reached 96.24% after cultured for 12 hours. Compared with the control group, the growth and survival times of RGC were similar (P = 0.595, 0.147) under the pressure of 20 mm Hg cultured for 48 hours, the expression of NF-H in RGC was not different (P = 0.227); but the growth and survival times of RGC were significantly different (P = 0.001, 0.000, 0.000 and 0.000, 0.000, 0.000) under the pressures of 40, 60, and 80 mm Hg, respectively. The expression of NF-H in RGC were significantly (P = 0.000, 0.000, 0.000) reduced under the pressures of 40, 60, and 80 mm Hg for 48 hours respectively. The growth and survival times of cultured RGC in vitro are affected by the pressure > 40 mm Hg leading to a decreased expression of NF-H indicating a pressure caused mechanism of RGC damage in glaucoma. Down-regulation of NF-H may influence the process growth of RGC.