Function Of Sodium Concentration Research Articles

An explanation for the correlation of sodium concentration in serum and red cell osmotic equilibrium

A direct correlation between red cell osmotic fragility and sodium concentration in serum has been observed in rats with experimental hypernatremia and hyponatremia. These effects developed as early as 20 minutes after injection of saline to induce hypernatremia. There was also a rapid reversal of changes in osmotic fragility when sodium concentration returned to normal. For example, red cells from control rats had less than 1.0 per cent hemolysis in 0.5 per cent saline; rats (196 mEq. per ,liter) had 31 per cent hemolysis. Attempts to effect these changes in osmotic fragility as a function of sodium concentration in vitro by incubation of red cells in hypernatremic and hyponatremic Ringer's solution were not successful. The difference, it was observed, lay in the fact that in vitro cells reached a new osmotic equilibrium by the passive movement of water alone; cell electrolyte content remained unchanged. In the rat with hypernatremia (average -212 m e g . per l i ter) , however, cell sodium content increased (control--7.0 mEq. per 100 Gm. dry red cells versus 16.1 mEq. for the hypernatremic); cell potassium was unchanged. Because of this gain in sodium, the reduction in cell water was correspondingly less. The data illustrate an essential difference in response between the red cell in an environment outside the body and one inside. In the former the changes in external sodium concentrations effect a predictable change in water content of the cells. The new cell water content can be predicted from the following equation:

Electrical Resistivity of Cubic Sodium Tungsten Bronze

The electrical resistivities of the nonstoichiometric compounds NaxWO3 have been measured as a function of sodium concentration from x=0.48 to x=0.88, and as a function of temperature from T=4°K to T=873°K. The minimum in electrical resistivity near x=0.75, which had been reported by earlier investigators, was absent in single crystals which were selected to be electrically homogeneous. Above room temperature, the electrical conductivity increased approximately linearly with sodium concentration; at liquid-helium temperatures, the electrical conductivity increased approximately as the fourth power of sodium concentration.