Chemical Studies of the Intrinsic Factor in Desiccated Stomach and Normal Human Gastric Juice. I. Separation of the Intrinsic Factor

Abstract

In previous reports it was demonstrated that the intrinsic factor of Castle was present in the gastric juice of individuals with pernicious anemia' as well as in the gastric contents of normal individuals. It was also shown that desiccated stomach contained both the extrinsic and intrinsic factors.' The object of this paper is to report some results of the fractionation of desiccated stomach and of normal gastric juice in an attempt to isolate the intrinsic factor and determine its nature.All the subjects used in the experiments were proven to have true pernicious anemia by the history, physical findings and laboratory procedures. T o each of these patients either various fractionation products of desiccated stomach or gastric juice incubated with beef steak were fed daily at 8 A. M. No food was permitted for at least 8 hours before this time or for 5 hours afterwards. Blood observations were made daily with U. S. Bureau of Standards equipment.Reticulocyte counts were made from brilliant cresyl blue film preparations; one thousand red cells were counted.An acidified water extract (pH 4.5) of desiccated hog stomach was prepared' and, after concentration by forced air drying at room temperature, the remaining clear yellow fluid was saturated with ammonium sulfate. The precipitate was removed by filtration and dialyzed in a Parlodion sac against distilled water for several days to remove the ammonium sulfate. The contents of the sac were then removed, dried, and fed daily to a patient with pernicious anemia in relapse (red blood cells 1,700,000 per cu. mm.; hemoglobin 64%). The daily dose was that amount of dried precipitate equivalent to 50 gn. of hog stomach. After 7 days of therapy a slight reticulocyte response was noted, indicative of a subminimal potency.The same patient was then fed the above described precipitate tolffoldhamer, S. M., Am.

Nature of the Intrinsic Factor of Castle

“…It is partially soluble in 80% alcohol and 80% acetone and is precipitated on saturation with ammonium sulphate (Helmer and Fouts, 1937;Goldhamer and Kyer, 1938).…”