Studies in Experimental Anemia

Abstract

In the first study (1) of this series chronic anemia was produced in rabbits by the injection of Welch bacillus toxin. The blood picture was characterized by (1) low color index, (2) anisocytosis without distortion of the shape of the cells, (3) rarity of nucleated red corpuscles. The histological examination of the organs showed changes consistent with blood destruction from any cause. Study of the spinal cord did not reveal the degenerative changes that are frequently found in pernicious anemia. The anemia which developed, however, was characterized by remissions when the injections were continued over long periods of time. The blood picture of rabbits which were given nonfatal doses returned to normal despite the continuance of injection of toxin. If large doses were then given the resistance could be broken down and anemia once more produced. This phenomenon could be repeated. It seemed theoretically possible that the remissions in pernicious anemia were due to a varying immunity on the part of the human organism to the Welsh bacillus toxin, and that furthermore, the protoplasm of the rabbit was not suited to produce the typical changes of pernicious anemia as they occur in man. For this reason it seemed important to determine the immunologic reactions associated with anemia due to Welch bacillus toxin and to compare them with those observed in pernicious anemia.Agglutination of the Welch bacillus is specific for strain. Simonds (2) inoculated animals with the whole organism and observed agglutination up to 1 to 60. Agglutination in higher dilution has been 539