Influence of Sodium Load on Sodium Excretion

Plasma sodium concentration and sodium excretion in the anaesthetized dog.

“…These findings relate the natriuresis to the rise in the salt levels at the kidney itself and not to any systemic consequences of hypersalaemia. The suggestions, that the natriuresis accompanying raised sodium chloride levels is due to the transfer of water into the animal's extracellular space (Green & Farah, 1949) or to dilution of its plasma proteins (O'Connor, 1962), are thus denied. The suggestion of O'Connor (1962) that the natriuresis may be a consequence of local haemodilution within the kidney may be more pertinent, for a local haemodilution did in fact occur during the hypertonic infusion into the renal artery, evinced by a fall in the renal venous levels of haematocrit and plasma solids.…”

“…So, despite an enormous literature, an unequivocal definition of the relationship between PNa and UN, V has not yet been formulated. Green & Farah (1949) and Selkurt & Post (1950) noted that when PNa was increased by rapid intravenous infusions of strongly hypertonic saline solutions in the dog there was, besides an increase in sodium excretion, an alteration in blood pressure and a fall in plasma protein concentration, haematocrit and arterial pH. Green & Farah (1949) argued that sodium excretion correlated with the volume of the intracellular water transferred to the extracellular fluid compartment; they concluded that PNa influences sodium excretion by the extracellular volume expansion it produces.…”

Studies of the Antidiuresis of Quiet Standing: The Importance of Changes in Plasma Volume and Glomerular Filtration Rate 1

“…When infusions of hypertonic saline are given to thirsted subjects, the rate of sodium excretion rises, but drops sharply when the serum sodium is suddenly restored to normal by the ingestion of a large quantity of water (49). Some workers have concluded that when an infusion of hypertonic saline is given, "changes in sodium excretion are invoked by differences between extracellular and intracellular osmotic pressures" (50). The present studies show that even when the concentration of sodium in the serum rises significantly, it is sometimes possible to prevent or reverse the usual renal response by standing upright.…”

The Effects of Concentrated Salt-Poor Albumin on the Metabolism and Excretion of Water and Electrolytes in Nephrosis and Toxemia of Pregnancy 12

“…Perhaps a similar mechanism exists in the patients with nephrosis and toxemia of pregnancy reported here since, when the concentration of sodium in the extracellular water rises in these edematous individuals, who are presumably well hydrated with respect to their interstitial space, there occurs an inhibition of the reabsorption of sodium. Green and Farah (38) have suggested that cellular dehydration may be the stimulus to salt excretion in dogs infused with sodium chloride solutions. This also has been hypothesized in man by Seldin and Tarail (39).…”