AIM: To evaluate the expression of transcriptional factor Islet-1 in retina in experimental retinal neovascularization induced by oxygen.

METHODS: The murine retinal neovascularization were induced by hyperoxia exposure.The morphological observation of retinal neovascularization was performed using angiography by fluorescein dextran injection under the fluorescence microscope, and the new blood vessels were quantified after 5d in room air(17-day-old)by counting the vascular epithelial cell nuclei protruding into viteous cavity using HE stain. Realtime PCR and Western blot were used to examine retinal Islet-1 level in postnatal 7,12, 14,17 and 26d respectively.

RESULTS: A lots of new blood vessels were demonstrated in the mouse retina in hyperoxic group by fluorescein angiography and histological method. Moreover, no significant difference was found in retinal Islet-1 level in postnatal 7d between hyperoxic group and control group, but was significantly higher in postnatal 12, 14 and 17d mice compared with control mice. However, mice at postnatal 26d, expression of Islet-1 in retina decreased to normal level.

CONCLUSION: In processing mouse model of retinal neovascularization, sustained hypoxia retinal tissue induce retinal neovascularization by increas the expression of transcription factor Islet-1.