Figure 1.

The renin-angiotensin system (RAS) is responsible for the maintenance of salt and water balance. Renin catalyses the conversion of angiotensinogen into angiotensin I which is converted by the angiotensin-converting enzyme (ACE) into angiotensin II (ANGII). ANG II controls the secretion of aldosterone, which stimulates Na⁺ retention and antidiuretic hormones (ADH) that stimulates H₂O reabsorption by the kidney. Plasma volume and plasma osmolality controls salt appetite and drinking behavior. High-Na⁺ intake leads to change in both plasma volume and osmolality, which exert a negative feedback on renin secretion. Ultimately, high-Na⁺ consumption induces a decrease in aldosterone concentration, which reduces Na⁺ reabsorption and increases sodium excretion. High-Na⁺ intake does not induce change in ADH plasma concentration, if the intake of H₂O is enough to maintain a Na⁺ and H₂O balance.