More importantly, our study showed the oxidative stress and apoptosis indices under apelin-13 treatment in the rat CI-AKI model, such as the expression of Nrf2, Keap1 and Cleaved caspase-3 and the levels of GSH, MDA ROS and TUNEL, and the downregulation of oxidative stress and apoptosis suggested the antioxidative and antiapoptotic effects of apelin-13 in vivo and in vitro. The gene discussed is CASP3; the disease is acute kidney injury.