Regardless of its causes the deposition of iron in the liver, if severe enough and persist for long period, is known to produce a portal or Laennec's type of cirrhosis (Anderson 1967).
However, Kleckner et al. (1955) insisted that cirrhosis is associated only in idiopathic hemochromatosis based on their studies of human autopsy materials. Witzleben and Shaffey(1955) and Dunn(1967) also stated that mere deposition of iron in the liver from either endogenous or exogenous origin does not produce damage to the liver or induce cirrhosis, nor enhance ethionine induced cirrhosis in the liver of rats. Further more, Pechet and MacDonald(1962) and Pechet et al. (1965) stated that a development of cirrhosis is not related to the amount of iron deposited in the liver.
In contrast to these reports, Kent et al. (1959) and Goldgerg and Smith(1960) reported that a deposition of iron in already injured liver by other causes will enhance the injurious effect and stimulate connective tissue proliferation. And even in the human liver changes indistinguishable from idiopathic hemochromatosis may develope following a prolonged and large amount of blood transfusion. A strict control mechanism in iron absorption, a so-called intestinal mucosal block, was previously advocated. But recently this blocking action is thought to be less strict one and can be modified by various factors, especially by the composition of food-stuff(Wintrobe 1961).
Siderosis in African Bantu tribe is known to be caused by excessive intestinal absorption of iron and if the degree of iron deposition is severe and persists a development of cirrhosis is observed (Bothwell and Isaacson 1962). Excessive iron absorption is also observed in drinkers(MacDonald 1963, Butt et al. 1964).
Bell(1955) thought that a cirrhotic liver contains more iron than a normal, and Conrad et al. (1962), Greenberg et al.(1964) and Deller(1965) stated that a patient with cirrhosis absorbs more iron than normal person.
These reports contradict each other and it is still not clear whether the iron deposition in the liver is innert or noxious, and if the patient with cirrhosis will absorb more iron. Present investigation is intended to investigate if orally administered exogenous iron will be absorbed excessively and enhance the hepatic damage induced by carbon tetrachloride injection in the rats.
Materials and Methods
Albino rats weighing around 200gms were used for the experiments, and divided into 4 groups and treated as follows.
Group Ⅰ: Normal untreated control (20 rats)
Group Ⅱ : Carbon-tetrachloride injection alone (20 rats)
Group Ⅲ : Carbon-tetrachloride injection plus ferrous sulfate administration (20 rats)
Group Ⅳ : Ferrous sulfate administration alone (20 rats)
Liquid carbon-tetrachloride was diluted to 50% concentration in salada oil, and it was injected subcutaneously once every other day in a dose of 1.3mg per Kg of body weight for six weeks. Ferrous sulfate was disolved in saline and given orally once every other day in a dose of 50mg per Kg of body weight for 8 weeks alone or in combination with carbon tetrachloride injection.
Changes of body weight were recorded in every 2 weeks. Five animals from each group were killed at 2 weeks' interval and gross and microscopical alterations of the liver were examined. Hematoxylin and eosin, Masson's trichrome, Gridley's reticulum and Mallory's iron staining were applied to the sections of the liver to examine histologic alterations.
Results and Summary
The administration of carbon-tetrachloride brought a decrease of body weight, which was followed by rapid increase after the cessation of administration. Combined administration of ferrous sulfate and carbon-tetrachloride produced similar result, but the administration of ferrous sulfate alone did not influence on the increase of body weight.
The weight of the liver was also decreased but not until the 4th week. The decrease was maximum at the end of the 6th week. It increased again after the cessation of carbon-tetrachloride in the animals treated with carbon-tetrachloride alone, but it decreased continuously inspite of the cessation of carbon-tetrachloride in the animals treated with carbon-tetrachloride and ferrous sulfate together.
A grossly noticeable cirrhotic changes of the liver appeared at the end of the 4th week and it reached to a maximum degree at the end of the 6th week. When the administration of carbon-tetrachloride was stopped, the liver restored normal appearance in the animals treated with carbon-tetrachloride alone in 2 weeks. In the animals treated with carbon-tetrachloride and ferrous sulfate together the degree of cirrhotic change was more marked and persisted longer after the cessation of carbon-tetrachloride administration. No notable gross alteration was noted in the liver of animals treated with ferrous sulfate alone.
Microscopical examinations revealed centrilobular necrosis with fatty degeneration and mild inflammatory reaction around necrotic area and in portal spaces at the end of 2nd week. It was followed by condensation of reticulum fibers, increased amount of fibrous connective tissue at the area where necrosis was present, and eventually fibrous septa which divide normal hepatic lobules into multiple atypical nodules was formed at the end of the 4th week. In the fibrous septa marked inflammatory reaction and proliferation of bile ductules are noted. At this stage, many large ballooned clear cells appeared scattered throughout the
liver. At the end of the 6th week a full-blown classical picture of a post-necrotic type of cirrhosis developed. Inflammatory reaction diminished rather markedly, but fibrous septa became collagenized and biliary proliferation was prominent. When the
administration of carbon-tetrachloride was stopped, almost complete restoration of normal hepatic architecture was noted within 2 weeks in the animals treated with carbon-tetrachloride alone. The degree of cirrhotic changes was more marked in the animals treated with carbon-tetrachloride and ferrous sulfate together, and the restoration of normal architecture was delayed after the cessation of carbon-tetrachloride administration. No evidence of hepatic damage was noted in the animals treated with ferrous sulfate alone.
No appreciable amount of stainable iron was present in the liver of normal rats.
The administration of ferrous sulfate alone brought a minimal increase of stainable iron deposition in the liver. However, in the liver of animal treated with carbon-tetrachloride showed increased amount of iron deposition, especially in the fibrous septa. It disappeared when the liver restored normal architecture after the cessation of carbon-tetrachloride treatment. In the animals treated with carbon-tetrachloride and ferrous sulfate together, the amount of iron deposition increased somewhat and persisted longer in fibrous septa. As a whole there was a tendency of increased iron deposition in the damaged liver, in the damaged liver cells at the early stage and in the siderophages of septa at the later stage, and there seemed to exist a certain relationship between the degree of cirrhotic
changes and the amount of iron deposition, as well as to the regeneration of liver lobules. Namely, if the hepatic damage was more marked, the iron deposition was more prominent, and if the iron deposition increased the regeneration of hepatic lobules delayed.