TY - JOUR T1 - Young research workers’ prize finalists JF - Heart JO - Heart SP - A1 LP - A3 VL - 92 IS - suppl 2 A2 - , Y1 - 2006/05/01 UR - http://heart.bmj.com/content/92/suppl_2/A1.abstract N2 - T. Chico, C. Gray, I. Packham, F. Wurmser, P. Hellewell, P. Ingham, D. Crossman.University of Sheffield, Sheffield, UK Introduction: Collateral vessel formation (arteriogenesis) is poorly understood. Collateral vessels develop from existing endothelial communications in a nitric oxide (NO) dependent manner, but the role of ischaemia is unknown. Current models of arteriogenesis suffer many disadvantages. Angiography is very difficult in small mammals. Ischaemia and necrosis limit microarray or proteomic studies. These issues hamper the study of arteriogenesis. The transparent zebrafish embryo is an emerging tool in vascular biology. The gridlock mutant has an aortic coarctation resulting in an occluded proximal aorta. We evaluated this mutant for its suitability as a model of arteriogenesis. Methods: Gridlock embryos expressing endothelial GFP were generated by crossing gridlock adults with transgenic Fli1-eGFP fish. To determine restoration of distal aortic blood flow, groups of 20–30 embryos were lightly anaesthetised and observed under a stereomicroscope. To determine the role of NO in restoration of distal aortic blood flow, embryos were incubated in L-NAME or L-arginine at the times and doses indicated. Confocal microangiography, digital motion analysis, and rt-PCR were performed as previously described. Results: At 48 h post fertilisation, wildtypes have brisk aortic flow whereas no gridlock mutant had detectable distal aortic blood flow. By 120 h post fertilisation, however, 83 (SD 6) % of gridlock embryos had recovered distal aortic flow, via a variable pattern of collateral vessels, detected by digital motion analysis and confocal microangiography. When incubated in L-NAME (up to 1 mM) from 24–120 h post fertilisation there was a dose-dependent reduction in the percentage of gridlock embryos with distal aortic blood flow, reversed by co-incubation with 1 mM L-Arginine (Control 90 (2), 1 mM L-NAME 41 (10), 1 mM L-NAME and 1 mM L-arginine 80 (10), p<0.05 L-NAME v control). This effect … ER -