Protoporphyrin, erythrocyte

Erythrocyte protoporphyrin (EF) elevation in males Erythrocyte protoporphyrin (EP) elevation in females ALA-D inhibition... 

Blood Chemistry Data. All blood specimens were obtained by venipuncture. The erythrocyte protoporphyrin (EP) was measured by the extraction method. Blood lead determinations were done In quadruplicate and are presented as an arithmetic mean of the four replicates. 

Dose-Response Curve for Erythrocyte Protoporphyrin (EP) as a Function of Blood Level in Subpopulations... 

The amount of total lead in the blood can be measured to determine if exposure to lead has occurred. This test can tell if you have been recently exposed to lead. Lead can be measured lead in teeth or bones by X-ray techniques, but these methods are not widely available. These tests tell about long-term exposures to lead. Exposure to lead can be evaluated by measuring erythrocyte protoporphyrin (EP) in blood samples. EP is a part of red blood cells known to increase when the amount of lead in the blood is high. However, the EP level is not sensitive enough to identify children with elevated blood lead levels below about 25 micrograms per deciliter ( ig/dL). For this reason, the primary screening method is measurement of blood lead. For more information on tests to measure lead in the body, see Chapters 2 and 6. 

PbB concentrations reflect the absorbed dose of lead. However, the interpretation of PbB data depends on a knowledge of the past history of exposure to lead. This is because in the body, bone constitutes the major lead sink and this results in lead having a long body half-life. Thus, in the absence of intense exposure to lead for a considerable period up to its body half-life, the PbB concentrations reflect recent lead exposures. However, if intermittent exposure to lead is occurring in several distinct environments, the PbB concentration reflects both recent and past exposures to lead. Thus, biological effects for populations with the same PbB concentrations may not be the same since different exposure times scales may be involved. This is the reason why free erythrocyte protoporphyrin (FEP) and erythrocyte zinc protoporphyrin (ZPP) have been used as additional biological markers since their elevation is more related to chronic lead exposure than acute lead exposure (see Section 2.7). 

ALA = 5-aminolevulinic acid ALAD = 6-aminolevulinic acid dehydratase ALAS = 5-aminolevulinic acid synthase EP = erythrocyte protoporphyrins FEP = free erythrocyte protoporphyrins FSH = follicle stimulating hormone IQ = intelligence quotient LH = luteinizing hormone NS = not specified (occup) = occupational Py-5 -N = pyrimidine-5-nucleotidase TSH = thyroid stimulating hormone ZPP = erythrocyte protoporphyrin... 

It is possible that lead s interference with heme synthesis may underlie the effects on vitamin D metabolism. Evidence that lead affects heme synthesis in the kidney was presented in the section on hematological effects. In addition, apparent thresholds for the effects of lead on renal vitamin D metabolism and for erythrocyte protoporphyrin accumulation are similar. 

Alessio L, Bertazzi PA, Monelli O, et al. 1976. Free erythrocyte protoporphyrin as an indicator of the biological effect of lead in adult males II. Comparison between free erythrocyte protoporphyrin and other indicators of effect. Int Arch Occup Environ Health 37 89-105. 

Angle CR, Kuntzelman DR. 1989. Increased erythrocyte protoporphyrins and blood lead—a pilot study of childhood growth patterns. J Toxicol Environ Health 26 149-156. 

Hammond PB, Bomschein RL, Succop P. 1985. Dose-effect and dose-response relationships of blood lead to erythrocytic protoporphyrin in young children. In Bomschein RL, Rabinowitz MB, eds. The Second International Conference on Prospective Studies of Lead, Cincinnati, OH April, 1984. Environ Res 38 187-196. 

Mahaffey KR, Annest JL. 1986. Association of erythrocyte protoporphyrin with blood lead level and iron status in the Second National Health and Nutrition Examination Survey, 1976-1980. Environ Res 41 327-338. 

Marcus AH, Schwartz J. 1987. Dose-response curves for erythrocyte protoporphyrin vs blood lead Effects of iron status. Environ Res 44 221-227. 

Roels HA, Balis-Jacques MN, Buchet J-P, et al. 1979. The influence of sex and of chelation therapy on erythrocyte protoporphyrin and urinary delta-aminolevulinic acid in lead-exposed workers. J Occup Med 21 527-539. 

Toriumi H, Kawai M. 1981. Free erythrocyte protoporphyrin (FEP) in a general population, workers exposed to low-level lead, and organic-solvent workers. Environ Res 25 310-316. 

If the patient presents with acute burning pain, the examination of choice is erythrocytic protoporphyrins. If the free protoporphyrin is significantly elevated (more than 6 pmol/1), the diagnosis of erythropoietic protoporphyria is established. Plasma porphyrins are used in patients on chronic hemodialysis who suffer from skin blisters to differentiate between PCT and pseudoporphyria the latter does not show increased plasma porphyrins. 

Fig. 7.3.7 Chromatogram of erythrocytic protoporphyrins from an individual with erythropoietic protoporphyria...

Griseofulvin interferes with porphyrin metabolism. In man, transient increases in erythrocyte protoporphyrin concentrations have been demonstrated, and the production and excretion of porphyrins is increased. Acute intermittent porphyria is an absolute contraindication to griseofulvin. In patients with other forms of porphyria it should also be avoided, in view of the many alternatives (458-463). 

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