Regulation of the renal proximal tubule second sodium pump by angiotensins

For several years it was believed that angiotensin II (Ang II) alone mediat ed the effects of the renin-angiotensin system. However, it has been observ ed that other peptides of this system, such as angiotensin(1-7) (Ang-(1-7)) , present biological activity. The effect of Ang II and Ang-(1-7) on renal sodium excretion has been associated., at least in part., with modulation o f proximal tubule sodium reabsorption. In the present review, we discuss th e evidence for the involvement of Na+- ATPase, called the second sodium pum p, as a target for the actions of these compounds in the regulation of prox imal tubule sodium reabsorption.