ABSTRACT
Objective To investigate the changes of morphological structures and biomechanical properties of scleral tissues in rabbits at different month ages. Methods The eyeballs of 1, 2 and 3 month-old New Zealand white rabbits were obtained for measuring the diameter and axial length, and the thickness of scleral tissues. Part of the scleral tissues was used to observe scleral structures with HE staining, some other part was used to observe collagen fibrils by electron microscope, and the left part were cut into strips and used to test the elastic modulus of the sclera on Instron 5544 system. Results The diameter, axial length of eyeballs and the thickness of the sclera were increased with month age. The elastic modulus of scleral tissues was also increased with month age. The numbers of scleral fibroblasts were decreased and the numbers of fiber bundles were increased with month age. The diameters of collagen fibrils were increased with month age. Conclusions In the post-embryonic stages, the structures of eyeball and sclera are changed continually, with growing numbers of thicker collagen fibers, and the biomechanical properties of scleral tissues are improved correspondingly. The mechanism of post-embryonic development in sclera is further explained in the study, which can provide theoretical guidance for prevention of sclera-related diseases.
ABSTRACT
● AIM: To investigate the sequential changes of HIF-1 α Protein and mRNA in hypoxic bovine retinal microvessel endothelial cells.● METHODS: The bovine retinal microvessel endothelial cells were cultured in normoxic and CoCl2-induced hypoxic conditions respectively. Expressions of HIF-1 α Protein were measured with immunohistochemical staining, and RT-PCR was used to determine the HIF-1 α mRNA.● RESULTS: HIF-1 α began to increase 1h after hypoxia,and reached the peak at 4h. After 16h, it declined significantly. Compared with the normoxic group, the expression of HIF-1 α protein in the hypoxic groups had significant difference (P＜0.01), and HIF-1 α mRNA expression was unchanged under hypoxia.● CONCLUSION: HIF-1 α participates in the hypoxic procedures in retinal microvessel endothelial cells, and hypoxia induce time-dependent changes of HIF-1 α protein expression, which is not modulated on the transcription level. Analysis of HIF-1 α expression revealed a temporal and spatial changes with regard to the hyperoxic repression, indicating that HIF-1 may play a major role in the development of retinopathy of prematurity and other ischemic retinal disorders such as diabetic retinopathy.