| Objective:The model of anterior segment ischemia(ASI) in rabbits after multi-rectus tenotomy in both eyes was established.To investigate the expression of VEGF in expremental anterior segment inchemia in rabbits, and inquire the contact with each other. And suramin has the inhibitory effect on VEGF. Then provide the therapeutical thinking for ASI.Materials and methods:54 purebred male Japanese White Rabbits without eye diseases,weighted 2.5±0.2 kg, were randomly divided into three groups, 18 (36 eyes) in normal sham-operated group,36 (36 eyes, left eye ) in ischemic injury group, and 36(36 eyes, right eye) in injury treatment group.In the normal sham-operated group,only the annular bulbar conjunctiva cut line does, not set up the model of ASI;left eyes in ischemic injury group will have multi-rectus tenotomy and use a balanced salt solution 1ml injection peribulbar; right eye as injury treatment group was given rabbits'peribulbar suramin injection 0.5mg.In accordance with the various time periods,respectively,3h,6h,1d,3d,7d,14d time period in each group were observed under slit-lamp anterior segment of the change,and then killed rabbit,take the anterior segment tissue to do HE and immunohisto-chemical examination,observation of VEGF at different times of anterior segment tissues expression.And measured the concentration of VEGF in aqueous humor by ELISA.The initial data are analyzed by SPSS13.0 packages. Results:(1)General observation: The rabbits ASI after four rectus tenotomy results in cornea edema opacity on the 3 hour. On the seventh day we found that cornea edema become more serious, arueous humor turbidity,pupil enlarged;On the foruteenth day we found that cornea edema become slightly,iris ischemia or necrosis,cataract.(2)Patholgical results: in ischemic injury group: postoperative 3 hours, corneal epithelial and stroma cells range neatly with no edema, iris epithelial cells are intacted, but range a little loose, without oedema, and threr are vessels in.6 hours, corneal epithelial cells still range neatly with no oedema; stroma cells range a little loose; iris epithelial cells are intacted,but range a little loose, slightly edema. On the first day corneae epithelium cells were arranged disorder,limbus corneae base suffered edema and a large number of inflammatory cells, red blood cells emigration;iris ciliary body epithelialis were arranged slightly disorder,cell spaces become more widen than normal group.The cell shape nearly normal.Corneae epithelium cells edema,ground substance has infiltrated inflammatory cells on the third day, a part of iris epithelium were disfigurated,leucocytes infiltrate within the matrix and sticked on the vessel wall,swam out.On the seventh day the corneae edema become more serious,endothelial cell swelling;a large group of iris epithelial cell become applan and cube shape,we can see obvious edema,vacuolar degeneration,cell nucleus pyknosis,caryotin distribute uneven,and it has infiltrated a large number of inflammatory cells,the number of leucocyte has increased in lumen of blood vessel.On the fourteenth day a large number of epithelial cell vacuolar degeneration ,iris ciliary body matrix edema become to lessen, and cell population,degeneration,necrosis and blood vessel had decreased. The cell shape in injuryed treatment group has more obvious improve than the injuryed group.(3)VEGF immunohistochemical results: The immunohistochemistry results showed that normal sham-operated group have weakly positive expression of VEGF at the iris epithelialis cell and vascular endothelial cell;after injury in ischemic injury group iris epithelial cells and vascular ednothelial cells expression of VEGF increased,mainly vascular endothelial cells.VEGF immunohistochemical score results showed that the normal sham-operated group at different time points showed no differences(p>0.05);ischemic injury group at different time points have significant difference,VEGF expression increased with time,3 hours begin rise,the expression of 7d to peak, 14d decline,the difference was significant(p<0.05).At different time points of normal sham-operated group,ischemic damage and injury treatment group in each goup were compared between groups with statistical significance(p<0.05).(4)ELISA results:the normal sham-operated group aqueous humor VEGF concentration at different time points showed no differences(p>0.05),the ischemic injury group at different time points have significant difference(p<0.05),the content of VEGF increased with time,3hours begin rise,the expression of 7d to peak,14d decline,the difference was significant(p<0.05).At different time points of normal sham-operated group,ischemic injury group and injury treatment group were compared bewteen group,each group compared have significant statistical difference(p<0.05).Conclusions:(1)Eyes of Rabbit can be used to establish anterior segment ischemia model.(2)After ASI coming with multi-rectus tenotomy and being re-sutured in the former position, the iris ciliary body tissue ischemia and oxygen deficiency, the VEGF content had increased, these results displayed that probably the one of the pathogenesy of the disease.(3)The ASI earlier period use suramin could restrain the expression of VEGF, so suramin has played an important role for the maintenance of anterior segment morphology and function of the organization. |
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