Biomaterial Database

Light-induced protoporphyrin release from erythrocytes in erythropoietic protoporphyria. 1982

S Sandberg, and A Brun

The photohemolysis of normal erythrocytes incubated with protoporphyrin is reduced in the presence of albumin. When globin is added to normal erythrocytes loaded with protoporphyrin, protoporphyrin is bound to globin. During irradiation protoporphyrin moves from globin to the erythrocyte membrane and photohemolysis is initiated. Erythrocytes in patients with erythropoietic protoporphyria contain large amounts of protoporphyrin bound to hemoglobin. Upon irradiation of these cells in the absence of albumin, 40% of protoporphyrin and 80% of hemoglobin is released after 240 kJ/m2. The released protoporphyrin is hemoglobin bound. In contrast, when albumin is present only 8% of hemoglobin is released whereas protoporphyrin is released to 76%. The released protoporphyrin is albumin bound. A hypothesis for the release of erythrocyte protoporphyrin in erythropoietic protoporphyria without simultaneous hemolysis is proposed. Upon irradiation protoporphyrin photodamages its binding sites on hemoglobin, moves through the plasma membrane, and is bound to albumin in plasma.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D011164	Porphyrias	A diverse group of metabolic diseases characterized by errors in the biosynthetic pathway of HEME in the LIVER, the BONE MARROW, or both. They are classified by the deficiency of specific enzymes, the tissue site of enzyme defect, or the clinical features that include neurological (acute) or cutaneous (skin lesions). Porphyrias can be hereditary or acquired as a result of toxicity to the hepatic or erythropoietic marrow tissues.	Porphyria,Porphyrin Disorder,Disorder, Porphyrin,Disorders, Porphyrin,Porphyrin Disorders
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011524	Protoporphyrins	Porphyrins with four methyl, two vinyl, and two propionic acid side chains attached to the pyrrole rings. Protoporphyrin IX occurs in hemoglobin, myoglobin, and most of the cytochromes.
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D005914	Globins	A superfamily of proteins containing the globin fold which is composed of 6-8 alpha helices arranged in a characterstic HEME enclosing structure.	Globin
D006461	Hemolysis	The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.	Haemolysis,Extravascular Hemolysis,Intravascular Hemolysis,Extravascular Hemolyses,Haemolyses,Hemolyses, Extravascular,Hemolyses, Intravascular,Hemolysis, Extravascular,Hemolysis, Intravascular,Intravascular Hemolyses
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012709	Serum Albumin	A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.	Plasma Albumin,Albumin, Serum