Changes in the extracellular- and intracellular-fluid phases of tissues during water diuresis in normal and hypoproteinaemic rats

Abstract

A standard amount of water (5% of their body weight) was admd. by stomach tube to normal and hypoprotein-emic rats. In normal rats the process of water diuresis was divided into 3 distinct periods: The absorptive period, preceding the onset of diuresis and characterized by a dilution of the plasma accompanied by a fall in the chloride and the Na concn. of both plasma and tissues, resulting in a decrease of the extracellular-fluid phase. The excretory period, corresponding to the height of the water diuresis accompanied by a marked increase in the chloride and Na concn. of muscle and a decrease of K resulting in an increased edema of the tissue. The terminal period: return to normal values for chloride, Na and K concn. in plasma and tissues. In hypoproteinemic rats the admn. of water produced a diuresis which was delayed in its onset and diminished in its volume. No further increase in the plasma water content and no significant changes in the amount of extra-cellular-fluid phase per 100 g. fat-free muscle were found. The water absorbed was "visibly" collected in the perirenal and retroperitoneal connective tissue, which was no much distended as to have a gelatinous consistency.