温泉と鉄代謝に関する研究

第3報 鉄泉の腸管内鉄吸収実験

抄録

Morphological studies have revealed the fact that drinking of ferruginous Water is as remarkably effective as large doses of reduced iron in iron deficiency anemia, in spite of extremely slight quantity of iron contained.
The author attempted biochemically to observe the intestinal iron absorption, which is the first step in the effect of drinking of ferruginous spring. The results obtained are summarized as follows:
1) It was found that the routine experiments with rabbits on intestinal iron absorption in which the rise of serum iron or tissue iron was measured as an index of absorption were not sufficiently dependable for observing the immediate absorption from the intestinal tract.
2) Serum iron has been described by other workers, as a factor involved in iron absorption.
From the author's experiments on anemic rabbit phlebotomized, it was suggested that iron absorption was influenced by the level of unsaturated iron-binding capacity, and there is a definite relationship between them.
3) The author devised what is called “supra-surviving double intestinal loop method”, an improved experimental wethal in intestinal iron absorption.
(1) Based on the withdrawal-test, it was presumed that iron entering into blood stream and iron accumulated in the jejunal mucosa were included in the quantity of absorption obtained by this method.
(2) There was considerable variations in the absorptive power of individual animals. On the other hand, the absorptive capacity of the upper jejunum in the same individual showed no significant difference, and the neighbouring two portions showed still less difference.
Strictly speaking, in the upper jejunum, the absorptive capacity of the lower area was slightly inferior to that of the upper.
It may be caused by the difference in the distribution of mesenteric blood vessel.
(3) The quantity of absorption was approximately proportional to the concentration of iron solution, injected into the intestinal loop (under 1500γ/10ml).
(4) When original “Genzo-yu” (pH 1.65) or H₂SO₄ solution (pH 1.60) was injected into the intestinal loop, pathologically serious changes developed in the jejunal mucosa. But these solutions, when diluted 4 or 5 times, showed no change.
(5) Absorption was influenced by pH of injected iron solution, and it was most remarkably accelerated in iron solution showing a pH of 1.15, which caused serious changes in the mucosa.
On the basis of further studies into the conflicting phenomena, it was evident that iron absorption in these experiments was considerably limited by secretion of intestinal juice.
4) By comparing the absorption of ferrugino s spring (“Genzo-yu”) water with that of FeSO₄ solution of the same concentration by this method, no significant difference was observed.
5) In this experimental method, some problems to be criticized was elicited and the author feels that it is probably unreasonable to make an inference from these experiments on iron absorption under physiological conditions.