Antiangiogenic Effects of Doxazosin on Experimental Choroidal Neovascularization in Mice

The present study was designed to evaluate the effects of doxazosin on experimental choroidal neovascularization (CNV) in mice. Six- to 8-week-old male C57BL/6 mice were divided into a control group and a doxazosin-treated group (5 mg/kg, i.p., daily). Experimental CNV was induced by laser photocoagulation. Seven and 14 days after laser induction, fluorescein angiography, choroidal flat mounts, and histological studies were performed to evaluate the fluorescence leakage, area, and thickness of CNV lesions, respectively. In addition, western blot analysis was carried out to assess the inhibitory effects of doxazosin on the PI3K/Akt/mTOR signaling pathway and the expression levels of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF), which are involved in CNV model. Compared with the control group, the doxazosin-treated group demonstrated significantly less fluorescence leakage on day 7 and 14 after laser induction. Both the area and the thickness of CNV lesions in the doxazosin-treated group were significantly decreased. Mechanistically, PI3K/Akt/mTOR signaling pathway activation was significantly suppressed in the doxazosin-treated group. The expression of HIF-1α and VEGF was also notably reduced by systemic doxazosin treatment. Doxazosin exerts antiangiogenic actions in an experimental mouse model of CNV and may be a potential adjunctive therapy for neovascular age-related macular degeneration in humans.