An experimental study of anti-angiogenesis with recombinant human kringle 5

To investigate the anti-angiogenesis effects of recombinant human kringle 5 (rhk5) eye drops on corneal neovascularization (CNV) in rabbits induced by alkali burn.

Forty New Zealand albino rabbits were burned on the central corneas of their right eyes by 1 mol/L NaOH for 60s. Animals were randomly divided into 4 groups, 10 rabbits each group. Then rhk5 eye drops with different concentrations were applied four times daily for four weeks on each group: 5 mg/L in group 1, 10 mg/L in group 2, 20 mg/L in group 3 and carrier solution in group 4 (controls). The occurrence and development of CNV was observed every other day by slit-lamp microscope, and the area of CNV was calculated. Then the rabbits were killed on the 28th day (d), and the corneas were taken for histopathological examinations. Pearson's analysis was used to analyze the correlation between the number of inflammatory cells and the area of CNV.

The occurrence of CNV in group 1 was (3.4 +/- 0.5) d, group 2 (6.8 +/- 0.4) d, group 3 (6.7 +/- 0.7) d and group 4 (3.7 +/- 0.5) d. Significant difference (P < 0.05) in the occurrence time of CNV was found between group 2 and the control. Compared with the control group, the CNV occurrence was significantly delayed in the group treated by 10 mg/L rhk5. No significant difference was found between control group and group 1, and between group 2 and group 3. The CNV areas of group 2 and group 3 were also smaller than the control group (P < 0.05). The area of CNV had close relationship with the retrocorneal membrane and with the number of inflammatory cells (P < 0.05).

Topical application of recombinant human rhk5 has prominent effectiveness on the inhibition of angiogenesis induced by alkali burn.