Hemosiderosis in lemurs

AbstractIn the late 1960s, pathologists at the San Diego Zoo began to notice iron storage in the internal organs of captive lemurs. Hemosiderin was found in liver, spleen, lymph nodes, duodenum, and occasionally other organs. This was most pronounced inLemur macaco, least pronounced inLemur catta, with the severity inLemur variegatus variegatusandLemur variegatus ruberfalling somewhere in between. Since 1968, 20 of 29 necropsied lemurs had hemosiderosis, three with hepatomas, three with cholangiomas, and one with a metastatic pheochromocytoma. In a preliminary attempt to compare their iron absorption, five black‐and‐white ruffed lemur (Lemur variegatus variegatus) weanlings and five rhesus monkey weanlings were each given ∼500 nmol/kg FeCI3(27.9 μg iron/kg) containing 5 μCi of59Fe in 0.1 M HCl via a nasogastric tube. Retained59Fe was measured by whole body gamma counting and found to be roughly the same in the two groups, possibly because insufficient quantities of iron were administered and/or excessive iron absorption becomes apparent only in older animals. Our conclusions were the following: (1) Hemosiderosis in lemurs is associated with tissue damage similar to that seen in humans with idiopathic hemochromatosis. (2) Because iron deposits occur both in parenchymal cells and reticuloendothelial cells, hemosiderosis in lemurs is probably not a model for idiopathic hemochromatosis in a pure sense.