The thick ascending limb of the loop pf Henle reabsorbs 25 to 30 % of the NaCl filtered through the glomerulus. Abnormally elevated Na reabsorption by this segment is link to salt-sensitive hypertension. Ang II is an important regulator of transport in the thick ascending limb, in part due to its modulatory effects on the balance between nitric oxide and superoxide. This pathway features the acute effects of Ang II in NO and O2- production in thick ascending limb. The information presented here is based on both genomic and physiological data.