Intestinal iron absorption under the influence of available storage iron and erythroblastic hyperplasia. Comparative studies in children with hereditary spherocytosis, nonspherocytic enzymopenic hemolytic anemia, acquired hemolytic anemia, vitamin B12 deficiency induced megaloblastic anemia, erythroblastic hypoplasia and aplastic anemia.
A high negative correlation (coefficient similar to 0.9) between increased 59Fe absorption from a diagnostic 0.56 mg 59Fe2+ dose and the depletion of available storage iron was observed in menstruating and pregnant women, fullterm and premature infants, blood donors, patients with infections, inflammations, tumors, hepatic cirrhosis, gastric surgery, increased urogenital or gastrointestinal blood loss. The increased diagnostic 59Fe2+ absorption is a reliable and sensitive indicator of at least depleted iron stores or prelatent iron deficiency as caused by iron malnutrition or maldigestion, increased iron requirement in pregnancy, infancy, urogenital or gastrointestinal blood loss. Although the messenger system which signalyzes the depletion of iron stores to the iron absorbing enterocytes of the duodenal and jejunal mucosa is not yet known available storage iron seems to control intestinal iron absorption under normal and the great majority o pathological condition in humans. Anemia per se or high erythropoietin levels in blood do not influence iron absorption since patients with even severe erythroblastic hypoplasia, aplastic anemia and megaloblastic anemia due to vitamin B12 deficiency absorb iron according to their iron stores. An only mild hyperplasia of the erythropoietic system in the bone marrow does also not effect iron absorption which was still under the control of available storage iron in patients with hereditary spherocytosis, nonspherocytic congenital hemolytic anemia due to glucose-6-phosphate dehydrogenase deficiency, acquired hemolytic anemia and vitamin B12 deficiency induced megaloblastic anemia..
D000293:Adolescent; D000328:Adult; D000741:Anemia, Aplastic / Q000378:metabolism; D000743:Anemia, Hemolytic / Q000378:metabolism; D000746:Anemia, Hemolytic, Congenital Nonspherocytic / Q000378:metabolism; D000747:Anemia, Hypochromic / Q000378:metabolism; D000749:Anemia, Megaloblastic / Q000209:etiology / Q000378:metabolism; D001772:Blood Cell Count; D001854:Bone Marrow Cells; D002648:Child; D002675:Child, Preschool; D004798:Enzymes / Q000172:deficiency; D004906:Erythrocyte Count; D004913:Erythrocytes, Abnormal; D004920:Erythropoiesis; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007223:Infant; D007408:Intestinal Absorption; D007501:Iron / Q000097:blood / Q000378:metabolism*; D000090463:Iron Deficiencies; D007504:Iron Radioisotopes; D008598:Menstruation; D011247:Pregnancy; D012156:Reticulocytes; D013103:Spherocytosis, Hereditary / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism; D014804:Vitamin B Deficiency / Q000150:complications
D004798:Enzymes; D006454:Hemoglobins; D007504:Iron Radioisotopes; D014168:Transferrin; D007501:Iron