Dietary chloride as a determinant of "sodium-dependent" hypertension.

The uninephrectomized rat given desoxycorticosterone (DOC) provides a classic model of "sodium-dependent" hypertension. In such rats, the extent to which a given dietary intake of sodium induced an increase in blood pressure depended on whether or not the anionic component of the sodium salt was chloride. With normal and high dietary intakes of sodium, sodium chloride induced increases in blood pressure much greater than that induced by approximately equimolar amounts of sodium bicarbonate, sodium ascorbate, or a combination of sodium bicarbonate and sodium ascorbate. A normal amount of dietary sodium chloride induced hypertension, whereas an equimolar amount of sodium bicarbonate did not increase blood pressure. This difference could not be attributed to differences in sodium or potassium balances, weight gain, or caloric intake. The DOC model of "sodium-dependent" hypertension might better be considered sodium chloride-dependent.