Incidental Finding of Megaloblastic-like Cells in Bone Marrow of One of Two Swine with Macrocytic Anemia and Achlorhydria *†

Ever since Ehrlich described the megaloblasts seen in pernicious anemia during relapse, there have been attempts by many investigators to produce experimentally an anemia similar in all respects to human pernicious anemia. Macrocytic anemia with the megaloblastic type of erythrocytic regeneration in the bone marrow, achlorhydria, and a specific response to a substance containing the anti-anemic principle are the criteria necessary to establish the presence of such an anemia. Thus far, efforts to produce a macrocytic anemia in experimental animals have not been uniformly successful, but it is agreed by many investigators that swine constitute a suitable experimental animal in which to study this problem.3' 16, 25, 32 Total gastrectomy1' 9, 15, 17, 18, 30 alone, or combined with liver damage,23 has produced only an occasional macrocytic anemia in animals. The usual resultant anemia is normocytic and hypochromic and in most cases responds to iron therapy. Davis4 reported the development of a "hyperchromic" anemia in dogs given daily doses of choline chloride. This not only responded to liver therapy but also to atropine sulfate, and on this basis the anemia was not considered to be due to a specific lack of the anti-anemia factor. Of extreme interest are the recent reports of Welch,25 Heinle,10 Cartwright,2 and their associates, who have been able to produce macrocytic anemias in swine fed diets deficient in pteroylglutamic acid and supplemented with a chemical antagonist of pteroylglutamic acid. The difference