MITOCHONDRIAL CHANGES INDUCED BY IRON ABSORPTION IN THE DUODENAL ABSORPTIVE CELLS OF RATS

Ultrastructure of the epithelial cells of the small intestinal villi, the surface epithelium of the large intestinal mucosa and some elements of the intestinal mucosal lamina propria in rats with acute uraemia

Electron microscopic studies on the dynamics of changes in the epithelial cells and some elements of the intestinal mucosal lamina propria were performed on rats after bilateral high ureter ligation. Simultaneously, they were referred to blood serum biochemical and electrolyte disturbances. The ultrastructural changes indicate that as early as in the initial period of acute uraemia water-electrolyte disturbances become evident, which are still increasing. In the later period cell organelles alter and bacterial infection sets in. Ultrastructural abnormalities of the intestinal mucous membrane are increasing proportionally to biochemical and electrolyte disturbances of the blood serum.

[Evolution of the storage site of iron-dextran after retrograde axonal transport in the rat central nervous system (author's transl)]

The uptake, transport, and storage of an iron-dextran complex (used as a neuroanatomical tracer in the nigrostriatal pathway of rat) by neurons of the CNS is described. The complex is taken up by endocytosis and transported by lysosomes. Some iron-containing mitochondria are observed within the nigral cell bodies. The neuronal labelling remains for 10 days. Thereafter, the iron labelling of neurons decreases. No important neuronal degeneration is observed as a result of iron toxicity. The iron lost by neurons is taken up by glial cells. It is converted into ferritin and increases the intracerebral endogenous iron content.

Ultrastructural and biochemical effects of D-penicillamine on mouse hepatocytes

The ultrastructural and oxidative metabolic effects of D-penicillamine were examined in hepatocytes of mice fed various concentrations of the drug for periods up to 11 days. In virtually all animals studied, membranous material in the form of whorls, sheaves, and irregular networks was observed in some bile canaliculi. In several mice a few mitochondria were substantially enlarged, with diameters of 4-6 micron. In other animals some mitochondria became quite elongated, measuring 10 micron in length but only 0.5 micron in width. Certain mitochondria had small deposits of dense material in their outer compartment. Lysosomes contained numerous small dense particles; aggregates of these particles were also observed free in the cytosol. Despite these alterations, the vast majority of hepatocytes showed no changes whatsoever. Study of isolated hepatic mitochondria derived from the experimental animals showed no alterations in oxidative metabolism. It may be concluded that, unlike other copper-chelating agents, D-penicillamine has little significant morphological and biochemical effect on mouse hepatocytes, even when its concentration exceeds standard clinical dosages.