Investigation of Mechanism of Diuresis Produced in the Rat by an Intravenous Infusion of Isotonic Solution of Sodium Chloride

Following intravenous infusions of isotonic saline a marked increase in the tubular rejection fractions for sodium and water occurred. Only a slight rise in inulin clearance was found. Since the expansion of plasma volume produced by 6% albumin in isotonic saline solution was less effective in producing a diuresis than a similar expansion of plasma volume by an infusion of isotonic saline the results suggest that plasma volume expansion alone could not account for all the effects observed in saline diuresis. Dilution of plasma proteins may have played some part but bilateral vagotomy or bilateral severance of the cervical cardiac branches of the vagus did not significantly affect the diuretic response to an intravenous infusion of 0.9% sodium chloride solution.