The Effects Of Intravitreal Urokinas On The Retinal Vascular Permeability In Rats

ObjectiveTo research the influence of intravitreal Urokinas (UK) on the retinal vascular permeability in rats.MethodsThirty healthy SD rats were randomly divided into two groups, experimental group and control group, of15animals each.Intravitreal UK was performed for experimental group and0.01M phosphate buffered saline (PBS) for the control group on the right eyes in rats. The dose of UK was350IU/4μl for the experimental group animals and4μl0.01M PBS for the control group. The rats were injected Evans Blue (EB) via the caudal vein after24hours. After2hours, all the right eyes of rats were removed, EB absorbance of invitreous was measured by the indirect enzyme-linked immunosorbent assay (ELISA). According to the concentration-absorbance relationship standard curve of EB, the concentration of EB in vitreous was obtained.Result1. When the concentration of EB in0-30ug/ml, its absorbance was in0.008-0.12,and it had a good liner relationship according to the concentration-absorbance standard curve of EB.The regression equation:y=0.0034x+0.0044,R2=0.9941,n=6.2. Removed the right eye under the microscope, the reflected light through the counea and pupil in the experimental group rats was blue, and the reflected light changed from one to another was unobvious;The reflected light in the control group was colorless, and individual animals appeared slightly blue. The reflected light in the experimental group was obvious blue than control group.3. The absorbance of EB in vitreous measured by ELIS A method:the average absorbance of EB invitreous in the experimental group was (0.0558±0.0112)/25μl, while the control group was (0.0145±0.0077)/25μl, the difference between the two groups was significant (t=11.746, P=0.000).4. The average concentration of EB in vitreous of the experimental group was (15.1078±3.2905) μg/25μl, while the control group was (3.3093±2.1615) μg/25μl, according to the concentration-absorbance standard curves of EB. The difference between the two groups was significant (t=11.607, P=0.000).Conclusion1. Intravitreal UK injection can increase the permeability of retinal vascular in rats.2. The Evans blue dye technique can be modified to be as sensitive and quantitative in measuring blood-retinal barrier breakdown.