Kallikrein-binding protein inhibits choroidal neovascularization

Abstract

Objective To observe the inhibitory effect of kallikrein-binding protein (KBP) on choroidal neovascularization.Methods Forty Brown Norway rats were randomly divided into the KBP groups and the control group,20 rats in each group,the right eye as the experimental eye.The rats were photocoagulated by 532 nm laser to induce CNV model.One week after laser photocoagulation,the rats were received FFA examination.At the second day after FFA examination,the rats of KBP group were received an intravitreal injection of KBP 5 μl (4 mg/ml KBP).The same volume of deionized water was injected into the rats in the control group.The rats of two groups received FFA examination at one,two and three weeks after injection.The expressions of vascular endothelial growth factor and pigment epithelium derived factor were observed using hematoxylin and eosin stain and immunohistochemistry stain.CNV leakage area and the cumulative absorbance of laser spot area were analyzed by Image-Pro plus 6.0 software.Results FFA examination showed that there were CNV and fluorescence leakage at one week after laser photocoagulation; one,two and three weeks after injection,the leakage decreased gradually in KBP group,but increased with time in control group.Compared with control group,the spot area and CNV in KBP group reduced gradually,but CNV was always there in control group.The differences of VEGF (F=1.29)and PEDF (F=6.29) expressions at one week after laser photocoagulation were not statistically significant (P＞0.05).The differences of VEGF and PEDF expressions at one,two and three weeks after injection were statistically significant(VEGF:F=14.16,66.89,24.34; PEDF:F=4.22,62.04,233.05; P＜0.001).Conclusion Intravitreal injection with KBP can inhibit CNV. Key words: Choroidal neovascularization/prevention & control; Kallikreins/antagonists & inhibitors; Animal experimentation