Based on the reduced stroke volume in the TAC model and increased renin expression in the 2K1C model, we hypothesized that in the TAC model, hypoperfusion in the kidneys directly leads to renin activation and in the long-term renal hypofiltration, fibrosis and atrophy, as has been shown by us and others for the clipped kidney in the 2K1C model (Krebs et al., 2007; Cheng et al., 2009). This evidence concerns the gene REN and persistent truncus arteriosus.