Fig. 5.

Rational for the acute kidney injury to chronic kidney disease transition in the two-stage unilateral ischemia-reperfusion injury (uIRI) model. The red line suggests a threshold of the glomerular filtration rate (GFR) for the animal to survive. The green line and blue line represent the projected GFR changes for the left and right kidneys. In the uIRI (A) and bilateral IRI (B) models, animals would either exhibit a full recovery in GFR if the injury is moderate or die within a few days if the injury is too severe. In the two-stage uIRI model (C), fatal IRI was induced in the left kidney while the right kidney was kept intact. Even though the GFR of the injured left kidney decreases below the survival threshold, the nonischemic right kidney could still maintain the animal to survive. After the GFR of the injured left kidney recovers above the survival threshold, the intact right kidney was removed. The animals would exhibit a partial recovery followed by a continuous decline in GFR.