ObjectiveTo investigate the pro-angiogenesis mechanism of isosorbide mononitrate by observeing its effect on the angiogenesis in Tg(flk1:EGFP) transgenic zebrafish. MethodsThe embryos incubated with isosorbide mononitrate (100, 300, 500, and 1 000 μg/ml) were taken as the experiment groups, and the embryos exposed to 0.5% DMSO were identified as the controls. The embryos were treated one hour before the postfertilization stage, and the status and length of the newly-formed blood vessels were observed under fluorescence microscope 24-26 h after treatments. The total RNAs were extracted from zebrafish embryos at 0, 6, 12, and 24 h after treatment; real-time quantitative RT-PCR was performed to examine the level of platelet-derived growth factor receptor β(PDGFRβ). ResultsIsosorbide mononitrate greatly promoted the growth of the intersegmental vessels in zebrafish (P<0.01). It also dose-dependently promoted the growth of vascular at concentrations 100, 300, and 500 μg/ml. The expression levels of PDGFRβ gene were increased in the experiment groups compared with DMSO group, with significant difference found at 12 h and 24 h after treatment (P<0.05, P<0.01). ConclusionOur data suggest that isosorbide mononitrate can up-regulate PDGFRβ expression and promote angiogenesis in zebrafish.