Susceptibility to renal injury varies among individuals. Previously, it was shown that individuals with healthy baseline endothelial dilatory ability in isolated renal arterioles developed less renal damage after 5/6 Nx. Whether in vivo pre-existing vascular integrity also predicts subsequent renal damage to 5/6 Nx is subject of the current study using intravital microscopy. In addition, we explored whether in vitro myogenic constriction of the extirpated kidney is also a predictor of renal damage after 5/6 Nx. Anaesthetized rats underwent intravital microscopy to envision glomerular afferent and efferent arterioles. After stabilization with a saline infusion, Ang II (30 ng/kg) was infused in the experimental group. Thereafter, renal damage was induced by 5/6 Nx and continued on saline infusion. During the intravital protocol, arterial blood pressure, heart rate and renal blood flow were measured. Images of glomeruli were recorded for measurements of changes in vascular diameter of the afferent and efferent glomerular arterioles. Myogenic constriction was investigated in vitro in small arteries isolated from the extirpated kidney at 5/6 Nx. After surgery, animals were followed for 12 weeks for measurement of blood pressure and proteinuria. Infusion of Ang II induced significant contraction of both afferent and efferent glomerular arterioles (p<0.001 compared to saline). Linear regression analysis between the change in afferent and efferent glomerular arteriolar diameter upon Ang II infusion and proteinuria 12 weeks after 5/6 Nx showed a significant correlation (r = 0.73; p=0.01 and r = - 0.90; p=0.01, respectively). Additionally, in vitro measured MC of small renal arteries correlated with proteinuria 12 weeks after 5/6 Nx (r = - 0.71, p = 0.02). Individual afferent and efferent responses to AII in the healthy rat is able to predict the severity of renal damage induced by 5/6 Nx. Further research underlying this baseline function can lead to novel preventive renoprotective therapies.