Studies on the rat liver following iron overload.

Sprague-Dawley rats were given Jectofer injections to obtain iron overload in rat liver Kupffer and parenchymal cells. The release of iron was studied on the light and electron microscopical level by bleeding of the iron loaded animals and comparing the results with non bled controls. During the mobilization of iron. Kupffer cells showed a rapid and almost complete disappearance of electron dense iron containing particles (IP) while there was only limited decline of IPs in the parenchymal cells. Iron was demonstrated with X-ray microanalysis at the ultrastructural level, and presence of acid phosphatase was revealed using a histochemical method based on precipitation of lead phosphate at sites of enzyme activity in combination with X-ray microanalysis. It was demonstrated that all IP-containing cytoplasmic bodies also showed presence of acid phosphatase implying that all of them represented lysosomes. The mechanism of release of iron from Kupffer and parenchymal cells was discussed with special emphasis on the role of the lysosomes and the relationship between their contents and other cellular structures.