[Experimental studies on metabolism of iron overload in dogs with carbon tetrachloride induced chronic hepatic injury (author's transl)].

In order to clarify the influence of iron overload in the liver, histological and histochemical examinations were performed on the dogs to which colloidal iron (chondroitin sulfuric iron) as well as inorganic iron (ferrous sulfate) was intravenously administered for a long period. The experimental animals were firstly divided into two groups were respectively subdivided into three groups; the two corresponding to the injected irons and the one with no iron injection. Also the liver iron content was measured by atomic absorption spectrophotometry when the animals were sacrificed. The results were summarized as follows: 1) Even in the group in which only CCl4 was given without any iron solution, positive iron granules were found in Kupffer cells or macrophages at the central necrotic zone of hepatic lobules. The liver iron content was 80.15 +/- 25.74 microgram/100mg wet weight and higher than that of 35.20 +/- 6.13 micro/100mg.w. w. in normal control group, however, there were no significant difference between these two values (Fig. 1). 2) In the group in which only colloidal iron was given, iron deposition was limited to the Kupffer cells and did not appear in hepatocytes unless the liver content reached to 978.0 microgram/100mg.w.w.. On the contrary, in the group in which only inorganic iron was given, positive iron granules were already found in hepatocytes at the peripheral zone of hepatic lobules with liver iron content of 157.7 microgram/100mg.w.w.. 3) In the group in which inorganic iron was administered with CCl4, positive iron granules were found in hepatocytes, even though the level of liver iron content was as low as 81.86 microgram/100mg.w.w. being far lower than that in the group without CCl4. 4) Liver iron content was well correlated with the duration of administration of iron solution, irrespective the kinds of injected iron. And the slope of the regression line in the group in which only colloidal iron was given was steeper than that in the group in which only inorganic iron was administered (Fig. 2). And also the slope of the regression line in the group in which colloidal iron was administered with CCl4 was steeper than that in the group without CCl4 (Fig. 3). 5) In the group in which colloidal iron was administered with CCl4, marked iron deposition was observed in Kupffer cells or macrophages at the central necrotic zone of hepatic lobules, and accompanied by hepatic fibrosis in chronic cases. These results indicate that the long-term administration of colloidal iron may accelerate the hepatic fibrosis when chronic hepatic injury co-existed, even if it seems that it is mostly metabolized in reticuloendothelial system of the liver.