Hypergravity Effects on the Retina and Intraocular Pressure in Mice.

Abstract

We investigated the effect of exposure to +10.0 G for 4 h on the intraocular pressure and the retina of mice. We exposed 10 mice to +10.0 Gz for 4 h by using a centrifugal acceleration test facility for animals. Intraocular changes were compared before and after hypergravity exposure. The eyeballs of the mice were enucleated after measuring the intraocular pressure. Tissue slides of the retina were prepared with hematoxylin and eosin (H&E) for histological examination and immunohistochemical analyses for vascular endothelial growth factor-A (VEGF-A), VEGF receptor 1 (VEGF-R1), VEGF-R2, glial fibrillary acidic protein (GFAP), and glutamine synthetase (GS). The average intraocular pressure was 7.7 ± 0.86 mmHg before the hypergravity exposure and 6.65 ± 0.67 mmHg after the exposure. No histological difference was observed between the retinas in the two groups. The levels of VEGF-A, VEGF-R1, VEGF-R2, GFAP, and GS as assessed by immunohistochemistry were increased in the group exposed to hypergravity compared to the control group. Repeated exposure to a high level of hypergravity could cause elevation of intraocular pressure and hypoxic damage to the retina.