Jing-Xue Ma | PubMed Health

PubMed2004

[Experimental choroidal neovascularization is inhibited by subretinal administration of Endostatin].

OBJECTIVE: Endostatin is an endogeneous angiogenesis inhibitor. The purpose of this study was to investigated the effect of Endostatin on the eyes of rats with experimental choroidal neovascularization (CNV). METHODS: Experimental CNV was induced by laser photocoagulation. Animals were given subretinal injections of recombinant human Endostatin 20 microl (5 g/L) or 0.9% chlorine sodium. The intensity of fluorescein leakage from the photocoagulated lesions was studied 13 days after photocoagulation. The area of CNV at each rupture site was measured using high molecular weight FITC-dextran (MW 2 x 10(6)) for high resolution angiography in RPE-choroid-sclera flat mounts. In addition, 8 eyes in each group were removed and fixed 14 days after photocoagulation, cut into thin sections. The sections were examined by light microscopy. Immunolocalization of Endoglin (CD105) and factor VIII on sections of CNV lesions was studied by immunohistochemical evaluation. RESULTS: After Endostatin injection, fluorescein leakage from the CNV lesions decreased significantly compared with the control eyes. The average area of CNV at sites of the Bruch's membrane rupture showed significant difference in eyes injected with Endostatin compared with control eyes. Endothelial cells demonstrated strong immunoreactivity of CD105 and factor VIII in CNV lesions of control eyes. CD105-positive cell were not detected in normal chorioretinal tissues. CONCLUSIONS: The development of CNV can be inhibited by injection of Endostatin, which suggest that Endostatin may be beneficial in treating CNV and that further studies can be considered to evaluate this possibility.

Angiogenesis Inhibitors↗

PubMed2004

[An experimental study on dissolving and detaching vitreoretinal interface with enzymes].

OBJECTIVE: To investigate the safety dosage of intravitreal injection of Plasmin, Hyaluronidase and their combination and to evaluate their efficacy in the formation of posterior vitreous detachment (PVD) through animal experiments. METHODS: Eight rabbits each were randomly assigned to one of six groups and one eye of each rabbit were experimental eye, the other is control eye. The position of drug injection was in posterior 1/3 of vitreous before papillary. The drug-injection groups were assigned as following: the first group-Hyaluronidase 20 IU (0.1 ml BSS), the second group-Hyaluronidase 30 IU (0.1 ml BSS), the third group-Plasmin 1 IU (0.1 ml BSS), the forth group-Plasmin 2 IU (0.1 ml BSS), the fifth group-Plasmin 3 IU (0.1 ml BSS), the sixth group- Hyaluronidase 20 IU (0.05 ml BSS) combined with Plasmin 1 IU (0.05 ml BSS); the control eyes were injected with BSS (0.1 ml) at the same position. The experimental rabbits were followed for 2 weeks, and in this period all eyes were examined with slit-lamp biomicroscopy, +90 D preset lens, indirect ophthalmoscope, electroretinography, B-scan, and optical coherence tomography. After two weeks, the animals were killed and the eyes enucleated. Scan electron and light microscopy were performed. RESULTS: Hyaluronidase concentration of 20 IU, Plasmin concentration of 1 IU and their combination didn't produce inflammatory response and retinal toxicity in the experimental eyes. 30 IU Hyaluronidase and 2 IU Plasmin both caused mild inflammatory response in the vitreous without retinal histological changes, while the latter caused a reversible decrease in the ERG b-wave. 3 IU of Plasmin caused severe inflammatory response with retinal histological and electroretinographic changes. In safety dosage neither Hyaluronidase nor Plasmin alone were successful in producing completely posterior vitreous detachment (PVD), but the latter can produce partial PVD. The combination of Plasmin (1 IU) and Hyaluronidase (20 IU) was effective on producing completely PVD without retinal toxicity. CONCLUSION: 20 IU of Hyaluronidase and 1 IU of Plasmin are safe to retina and others structures in the eyes without any toxicity. Posterior vitreous injection of Hyaluronidase (20 IU) combined with Plasmin (1 IU) can produce complete posterior vitreous detachment.

Animals↗