research has shown that exposure to lead may have adverse effects at different blood lead concentrations. lead inhibits at least two enzymes that are essential for the formation of heme, and because of the interaction of lead with these enzymes, no iron is inserted into protoporphyrin. therefore the concentration of protoporphyrin increases in erythrocytes. the concentration of lead was measure...

Research has shown that exposure to lead may have adverse effects at different blood lead concentrations. Lead inhibits at least two enzymes that are essential for the formation of heme, and because of the interaction of lead with these enzymes, no iron is inserted into protoporphyrin. Therefore the concentration of protoporphyrin increases in erythrocytes. The concentration of lead was mea...

BACKGROUND Laboratory diagnosis of erythropoietic protoporphyria (EPP) requires a marked increase in total erythrocyte protoporphyrin (300-5000 μg/dL erythrocytes, reference interval <80 μg/dL) and a predominance (85%-100%) of metal-free protoporphyrin [normal, mostly zinc protoporphyrin (reference intervals for the zinc protoporphyrin proportion have not been established)]; plasma porphyrins a...

Bovine blood is used frequently as control material in interlaboratory comparisons for blood-lead analysis, but an erythrocyte protoporphyrin control material is needed. We present data on the rate of changes in blood lead and erythrocyte protoporphyrin in steers fed lead acetate. We also show, by comparison of fluorescence spectra with those of known compounds, that most of the porphyrin in le...

A patient with idiopathic sideroblastic anemia and atypical clinical and biochemical findings is described. He had a greatly increased erythrocyte and plasma protoporphyrin, but normal urine and fecal porphyrins. The erythrocyte protoporphyrin had a fluorescence spectrum typical of free protoporphyrin, but caused no photosensitivity. Bone marrow metal chelatase activity was normal. There were n...

A patient with greatly increased erythrocyte protoporphyrin, but normal porphyrins in urine and feces. is described. The patient later developed a malignant lymphoma. and the reason why she accumulated protoporphyrin in her erythrocytes is not known. The protoporphyrin in the erythrocytes consisted of two types of protoporphyrin. free protoporphyrin (30%) and zinc protoporphyrin (70%). Upon irr...

Porphyrins are widely distributed in living cells throughout nature and play essential roles in various metabolic processes such as photosynthesis, transportation of oxygen and cellular respiration. In man the most important of the porphyrins is protoporphyrin 9, type III, which in combination with iron and specific proteins forms such compounds as hemoglobin, myoglobin, cytochrome, peroxidase ...

Protoporphyria is a genetic disorder in which liver damage is caused by the toxic effect of protoporphyrin accumulation in the liver. In this study protoporphyrin was measured in the resected livers of 7 patients who had liver transplantation and an additional patient from whom liver tissue was obtained post mortem. Comparison of liver, erythrocyte and serum protoporphyrin levels demonstrated a...