Observations on the Mechanism of Decreased Tubular Reabsorption of Sodium and Water during Saline Loading*

Boston, Mass.) It has been demonstrated by several recent studies that the regulation of sodium excretion involves factors other than the total filtered load of sodium and the renal tubular effects of mineralocorticoids. Contrary to earlier suggestions that an increase in the filtered load of sodium may be sufficient to account for the natriuresis of saline loading in the dog, de Wardener, Mills, Chapman, and Hayter (1) reported that the administration of saline to dogs receiving an exogenous mineralocorticoid results in an increased excretion of so