Localization of lipofuscin in the duodenums of vitamin E-deficient rats.

In human malabsorption syndromes, lipofuscin accumulation has been reported to occur exclusively within the muscle layers of the intestine. It has been widely speculated that this lipofuscin deposition is related to vitamin E deficiency. To determine whether vitamin E deficiency leads to the same pattern of intestinal lipofuscin accumulation as that seen in many human malabsorption syndromes, the duodenums of rats that had been fed a vitamin E-deficient diet for 17 or 34 wk were examined for the presence of lipofuscin. Lipofuscin did not appear in the muscle layers of the duodenum until 34 wk, at which time occasional fibers containing large amounts of lipofuscin were present. An earlier and more pronounced deposition of lipofuscin occurred within connective tissue cells of the intestinal villi. After 17 wk, many fibroblastlike cells in the lamina propria of the villi contained large amounts of lipofuscin. By 34 wk, the numbers of these lipofuscin-containing cells in the lamina propria had increased substantially, and scattered cells containing lipofuscin were also seen in the submucosa. The difference in intestinal lipofuscin distribution between vitamin E-deficient rats and humans with malabsorption syndromes suggests that other factors, in addition to vitamin E, probably play important roles in regulating lipofuscin accumulation in the intestine.