鉄の吸収に関する実験的研究 第二編 胃に於ける鉄の吸收と胃内pH, Cl⁻及びNa⁺との関係

As has been described in Part 1 the author revealed that the stomach has an active ability to absorb iron, but the absorption ceases at a certain period of time after the iron introduction, showing not and quantitative relation with the amount of iron introduced. In this paper the author reports the precise mechanism of iron in the stomach, with the mechanism of the eessasion of iron absorption at a certain period. In rabbits the stomachs were separated from the continuous digestive canals by the same method described in Part 1. After the iron introduction the pH level, Na⁺, Cl⁻ and iron in the stomach and iron level in blood serum were estimated quantitatively at fixed intervals. The results proved that pH level of the contents of stomachs rose rapidly after the iron introduction with the increase of the sodium ion, but chlorine ion also was found to increase with the similar rapidity. the iron contents in the stomach decreased as in the cases of Part 1 with an increase in the level of serum iron. The pH level reached a plateau after about 3 hours, mean value pH 4, where the iron absorption stopped. From these observations the author concluded that the absorption of iron in the stomach is closely related with the pH level in stomach, showing iron can be absorbed only in the pH level where the ionization of iron is possible. The cessation of iron-adsorption often occurring at a certain period is caused by an elevation of pH in the stomach. However, the mechanism of the elevation of pH level seen after the iron indtroduction remains unexplained, because the theoretical calculation proves that the increase of Na⁺ occurring after the iron introduction is nut sufficient to elevate the pH as to neutrize the concomitant increase of chlorine ion.