The effects of repeated intravenous injections of distilled water on the blood picture in rabbits.

The effect of repeated induced intravascular hemolysis upon the blood of rabbits was studied in the following manner: Ten to 12 cc. of sterile distilled water were injected slowly into the marginal ear veins of 6 rabbits at 48 hour intervals. The number of injections varied, the maximum being 34. Recently, as a control experiment, Patterson and Kast 1 described an anemia in rabbits produced by the intravenous injection of sterile distilled water, but as their experiments were only continued for 19 days, they apparently did not observe that the animals subsequently developed an increased resistance to such injections.

The following constituents of the blood were studied; erythrocytes, hemoglobin, leucocytes and reticulocytes. The resistance of the erythrocytes against hypotonic salt solution was also determined. The examinations were made immediately preceding each injection. Control observations were made upon normal rabbits and rabbits which had received physiological salt solution in doses corresponding to the distilled water.

After various intervals following the repeated injections of water, there was a diminution of 40 per cent to 50 per cent in the number of erythrocytes. However, despite continued repeated injections the erythrocyte count returned approximately to the original figures. There was a slight to moderate poly-chromatophilia and anisolcytosis with an occasional normoblast and hemacytoblast. The number of reticulocytes showed a slight increase; the highest figure was 7 per cent. The variations in the percentage of hemoglobin were less marked than in the number of erythrocytes. The total number and differential count of the leucocytes remained within normal limits. The resistance of the erythrocytes against hypotonic salt solution did not change beyond the limits of normal variations in rabbits.