THE DISTRIBUTION OF ASCORBIC ACID BETWEEN CELLS AND SERUM IN RELATION TO ITS URINARY EXCRETION

Abstract

In fasting blood, a general correlation exists between the ascorbic acid (AA) concentration in cells and serum; that in cells is consistently higher. The whole blood conc. of AA appears to correspond almost lineally to the degree of saturation of exptl. subjects, and closely indicates the different phases of complete saturation produced by test doses of AA, as measured by the amts. excreted in urine. Serum and whole blood concs. are only roughly correlated. The detn. of AA in whole blood is to be preferred for practical purposes. The urinary elimination of large amts. of AA, following intake of a test dose by saturated subjects, depends on its conc. in the serum, on the amts. filtered therefrom in the glomeruli, and on the rate of tubular reabsorption. The relations between the curve of excretion and the concs. in cells and serum suggest that the rate of reabsorption by the tubule cells may depend upon the conc. of AA in these cells. AA is taken up from the plasma by red cells both in vivo and in vitro at a slow rate.