Abstract

1. The absorption of ferrous and ferric compounds was compared by injecting their solutions (5 cc. containing 50 mgm. of Fe) into ligated intestinal loops of rabbits. Three hours later the animal was killed. The content was analyzed according to the recent very accurate iodometric micromethod of Rappoport (10), where corresponding to each atom of Fe, 6 atoms of iodine are liberated.

2. The average percentage of iron absorbed was established for ferrous chloride 61.6 per cent of the iron injected; in glutamiron,

[See table in the PDF file]

a complex ferrous compound (approximately composed of one molecule of ferrous glutamate, one molecule of glutamic acid and two molecules of ferrous chloride) the average absorption was still somewhat better (76.0 per cent). Glutamiron appears to be a type of ferrous iron, which is suitable to absorption and far more stable than ferrous chloride.

3. The absorption of ferrous sulphate in rabbits was incomparably poorer (average percentage 39.7 per cent) than of ferrous chloride and of glutamiron.

4. The absorption of ferric compounds (ferric chloride and ferrum citricum ammoniatum oxydatum) was still more incomplete (19.8 and 30.5 per cent). The analysis of the intestinal walls of the injected loops revealed that more iron is retained within the intestinal walls when injected in the ferric than in the ferrous form, probably owing to the precipitation of proteins by ferric iron.

5. The absorption of ferrous iron is decidedly impaired by an acid reaction of the intestinal contents (produced by the addition of glutamic acid hydrochloride, which is very liable to dissociation).

6. The toxicity of ferrous and ferric compounds was compared by subcutaneous injection on mice. There was no simple interrelationship between the toxicity and the rate of absorption from intestinal loops.

7. The speed of diffusion of ferric and ferrous compounds into gelatine jellies containing K₄FeCy₆ and K₃FeCy₆ was compared by observing the zone Qf precipitated prussian blue and turnbulls blue. The ratio d/√t (d = path of diffusion, t = time) as a measure for the speed of diffusion was for ferrous chloride 19.5, glutamiron 19.1, ferrous sulphate 17.5, ferrous ammonium sulphate 15.9, ferrous glutamate 15.5, ferrous lactate 14.5, ferrous oxalate 5.7, ferric chloride 13.4, ferric sulphate 10.0, ferric ammonium citrate 12.2. The speed of diffusion of ferrous compounds is decidedly greater than the speed of diffusion of corresponding ferric compounds. There exists a certain limited analogy between the speed of diffusion and the rate of absorption.