A study of the gastric hematopoietic factor by hemoculture methods.

E SUCCESS of liver therapy in Addisonian pernicious anemia and the elucidation of the role of the stomach in blood formation are milestones of modern hematology. According to Castle’s hypothesis, normal gastric juice contains a special substance, intrinsic factor, produced by the gastric mucosa. This substance reacts with an extrinsic factor contained in the food. The production is an antianemic substance, absorbed via the gut into the bloodstream, deposited in the liver, and gradually utilized by the bone marrow in the process of blood formation. The nature of the intrinsic and extrinsic factors is not altogether clear. It is known that the intrinsic factor is thermolabile, distinct from pepsin and hydrochloric acid, and is absent or minimal in the gastric juice of individuals with pernicious anemia. Lasch regards the intrinsic factor as the third ferment of the stomach and as a proteolytic enzyme when pepsin is inactivated. Other investigators, who obtained a therapeutic antianemic effect by administering pure gastric juice alone, without extrinsic factor, consider the intrinsic factor a hormone. Greenspan regards the stomach as a dual gland, bike the pancreas, with endocrine as well as exocrine secretions. Studies conducted by Lester Smith, G. B. Glass and Boyd enabled us to evaluate the nature of the extrinsic and intrinsic factors participating in this process. The extrinsic factor is B12 and the intrinsic one, a special protein (gastromucoprotein) which is formed within the mucous membrane of the stomach. Gastromucoprotein secures the absorbtion of B12 by the intestine. Thus, the antianemic function of the stomach may be considered as a part of the general process of digestion. This conception, however, cannot completely solve the problem of the participation of the stomach in hematopoiesis. Nobody disputes the facts of the hematopoietic activity of the pure gastric juice or parenterally introduced metabolites and extracts of the human stomach. These data were obtained by the method of rat-reticulocytic reaction (Singer’s method). It can he suggested that, alongside with gastromucoprotein, the stomach produces another hematopoietic substance which is capable of exerting a direct stimulating effect upon hematopoiesis, acting quite independently from B12. The present paper deals with a study of i ire gastric juice in man and dogs, by means of a new biologic technic, i. e., hemoculture. The quantitative determination of hematopoietic factor in gastric juice is (lone as follows: 10 to 15 ml. of blood are drawn and a white cell film is made. The film is cut into shallow pieces of 1 sq. mm. in diameter and cultured in neutralized gastric juice, the latter being previously diluted 8 times with Ringer’s solution and sterilized by straining through a small porous filter.