Pearl P. Swanson

Inorganic Salts in Nutrition. III. Some Effects of Replacing Inorganic Salts in a Ration Poor in Ash.

It has previously been shown 1 that in rats 130 days old which, for the 90 days preceding the determinations, had been given an experimental ration extremely poor in inorganic salts and whose body weight had thereby been maintained at the level of 160±10 gm., there occurred striking alterations in the blood. When compared to animals of the same age which had grown at the usual rate, the stunted rats had blood with a striking increase in the number of erythrocytes, a marked decrease in relative concentration of hemoglobin and a significant diminution in the red cell volume. These changes have been shown to be independent of the concentration of the blood, the quantity of dietary protein consumed and the amount of total food eaten and have been attributed to the marked deficiency of mineral salts in the experimental ration which was otherwise adequate. Data are now available on a few rats which, after having been given the same experimental treatment as those animals described above, were realimented with a qualitatively complete diet. This ration was so adjusted that, although the quantity of the indispensable factors—protein, salts and vitamins—ingested was the same as that consumed by a normal rat of the same weight, the energy intake was limited to prevent increase in body weight. The observed results appear in the accompanying table. It is seen that the red cell count decreases progressively until at the end of six weeks it is somewhat below the normal level. Furthermore, at the end of the period of realimentation both the cell volume and the hemoglobin have made substantial increases toward the normal value. The bloods of some of the experimental animals were examined for reticulocytes.