NOS3 and hypertensive disorder: N(gamma)-nitro-L-arginine methyl ester (L-NAME) is an inhibitor of nitric oxide synthase (NOS), and L-NAME is one of the commonly used compounds to induce PE in experimental animals.(10,11) The reason is that endothelial nitric oxide synthase (eNOS) plays an important role in protecting blood vessels from hypoxia and ischemia, which are major causes of hypertension in PE.(10) Therefore, in this study, L-NAME (125 mg/kg per d)-treated Sprague-Dawley (SD) rats were used as the positive control group for inducing PE.