The Renin-Angiotensin-Aldosterone System and Sodium Appetite in Rats

Abstract

Richter (1) was the first to show that bilateral adrenalectomy induced a specific appetite for sodium chloride (NaCl) solutions in rats. This appetite was normalized by adrenal cortical transplants, implicating an hormonal factor which we now recognize as aldosterone. Accordingly, administration of graded doses of aldosterone or of desoxycorticosterone acetate (DOCA) to adrenalectomized rats produced a graded reduction in salt appetite (Figure 1, top panel). However, doses of DOCA in excess of about 1 mg/kg/day increased NaCl intake, resulting in a U-shaped dose-response relationship. In these experiments 0.15 M NaCl solution was given in simultaneous choice with distilled water, the intake of which was the mirror image of the NaCl curve (Figure 1, lower panel). High doses of aldosterone or DOCA also induce sodium appetite in intact rats (2,3).