acid-phosphatase and Hemochromatosis

Iron is an essential nutritional element for all life forms. Iron plays critical roles in electron transport and cellular respiration, cell proliferation and differentiation, and regulation of gene expression. Two emerging new functions for iron are its necessary role in supporting transcription of certain key genes required for cell growth and function [eg, nitric oxide synthase, protein kinase C-beta, p21 (CIP1/WAF1)] and its complex role in hematopoietic cell differentiation. However, iron is also potentially deleterious. Reactive oxygen species generated by Fenton chemistry may contribute to major pathological processes such as cancer, atherosclerosis, and neurodegenerative diseases. Iron-generated reactive oxygen species may also function in normal intracellular signaling. Therefore, roles of iron are both essential and extraordinarily diverse. This symposium explores this diversity by covering topics of iron absorption and transport, the regulation of gene expression by iron responsive proteins, the cellular biology of heme, hereditary hemochromatosis, and clinical use of serum transferrin receptor measurements.

Topics: Acid Phosphatase; Animals; Cell Division; Cell Respiration; Electron Transport; Gene Expression Regulation; Hematopoiesis; Hemochromatosis; Humans; Iron; Macrophages; Monocytes; Oxidation-Reduction; Protein Kinase C; Reactive Oxygen Species; Receptors, Transferrin; Transcription, Genetic

Topics: Acid Phosphatase; Hemochromatosis; HLA Antigens; Humans; Iron; Liver; Myocardium; Pigments, Biological; Skin

1. Iron, acid phosphatase and N-acetyl-beta-glucosaminidase were assayed in liver biopsies from control subjects and patients with primary and secondary haemochromatosis. 2. The activities of the lysosomal enzymes were significantly higher in liver biopsies from patients with iron overload than in those from other patient groups. 3. Lysosomes from the livers of patients with iron overload were strikingly more fragile than those of control subjects as demonstrated by assays of latent and sedimentable N-acetyl-beta-glucosaminidase. 4. Lysosomal integrity was essentially normal in biopsies from patients with a wide variety of chronic liver diseases. 5. It is suggested that iron accumulation damages lysosomal membrane, releasing acid hydrolases into the cytoplasm and thus initiating cell damage.

Topics: Acetylglucosaminidase; Acid Phosphatase; Biopsy; Hemochromatosis; Hexosaminidases; Humans; Iron; Liver; Lysosomes

Topics: Acid Phosphatase; Centrifugation, Density Gradient; Esterases; Galactosidases; Glucosidases; Glucuronidase; Hemochromatosis; Hemosiderosis; Hexosaminidases; Histocytochemistry; Iron; Lysosomes

Topics: Acid Phosphatase; Alkaline Phosphatase; Anemia, Aplastic; Bone Marrow; Disease; Hemochromatosis; Histocytochemistry; Humans; Hypersplenism; Leukocyte Count; Lymphatic Diseases; Methods; Mononuclear Phagocyte System; Multiple Myeloma; Neutrophils; Staining and Labeling