Some hemodynamic and hydroelectrolytic alterations of chronic salt deprivation

Male Wistar rats were fed for 1 month on a low salt diet and compared with control animals. The body fluids are decreased, and this diminution takes place due to the decrease of the total water, extracellular space, intracellular space, plasma volume and interstitial liquid. In the muscle, the alterations in the water composition were similar to the modifications observed in the whole animal. The electrolytic composition of the muscle showed a decrease in the sodium content; no modifications were found in the chloride content and there was a slight decrease in the potassium content. The cardiac rate was increased and the arterial pressure and heart weight also showed a slight augmentation. The infusion of antibodies against angiotensin II provoked a similar decrease in arterial pressure in both groups of animals. These results show an alteration of the hydroelectrolytic metabolism in salt-deprived rats and that the circulatory function is adapted to this new situation.