NOS3 and preeclampsia: Wang et al. (2017) also stated that the treatment with apelin remarkably improved the endothelial nitric oxide synthase (eNOS) expression in the placenta and in the serum and proposed that reconditioning of the eNOS/NO pathway might be engaged in the ameliorative effects of apelin on preeclampsia. Antifibrotic actions of apelin by the apelin/APJ/Akt/eNOS pathway that oppose Ang II have also been notified in unilateral ureteral ligation- induced renal fibrosis (Nishida et al., 2012).