losartan-potassium and Lead-Poisoning

Kathmandu tricycle taxi drivers, whose environmental lead (Pb) exposure is ascribable mainly to vehicular exhaust, were studied to examine a dose-response relationship between blood Pb (Pb-B) and serum erythropoietin (sEPO) concentrations.. Subjects were 27 drivers and 9 non-drivers. They were non-anemic healthy men with normal renal function. Pb-B was measured by an atomic absorption spectrometer with a graphite furnace, and sEPO was determined with a sandwich-type enzyme-linked immunosorbent assay.. sEPO levels in drivers were lower than those of non-drivers, while Pb-B levels in drivers were higher than those of non-drivers. There was an inverse relationship between Pb-B and sEPO.. The data suggest that Pb inhibits renal EPO production in a dose-dependent manner in persons with subclinical Pb toxicity. sEPO may serve as an early biochemical marker of subclinical Pb toxicity.

Topics: Adolescent; Adult; Air Pollutants, Occupational; Bicycling; Biomarkers; Case-Control Studies; Dose-Response Relationship, Drug; Erythropoietin; Humans; Lead; Lead Poisoning; Male; Middle Aged; Nepal; Occupational Diseases; Transportation

We test the hypothesis that chronic lead (Pb) exposure may be associated with an inability to maintain an adequate serum erythropoietin (EPO) concentration. From a longitudinal study of Pb exposure and infant and childhood development, we measured blood Pb (BPb) and serum EPO concentrations serially at ages 4.5, 6.5, 9.5, and 12 and tibia (cortical) Pb concentration at age 12. Pb-exposed children aged 4.5 and 6.5 produced increased concentrations of EPO to maintain normal Hgb concentrations. EPO production declined between ages 4.5 and 6.5. At ages 9.5 and 12, further diminution of the association was found. No association was found between tibia Pb and EPO. The continued decline in the slope of the relationship between EPO and BPb with age, after adjustment for hemoglobin, implies a gradually decreasing capacity to produce EPO.

Topics: Child; Child, Preschool; Environmental Exposure; Erythropoietin; Female; Hemoglobins; Humans; Infant; Infant, Newborn; Lead Poisoning; Male; Pregnancy; Prenatal Exposure Delayed Effects; Prospective Studies; Regression Analysis; Yugoslavia

To determine whether haematopoietic progenitor cells and erythropoietin (EPO), which is an essential humoral stimulus for erythroid progenitor (BFU-E) cell differentiation, are affected by lead intoxication.. In male subjects chronically exposed to lead with and without anaemia, pluripotent (CFU-GEMM), BFU-E and granulocyte/macrophage (CFU-GM) progenitor cell counts in peripheral blood were measured with a modified clonal assay. Lead concentrations in blood (PbB) and urine (PbU) were measured by the atomic absorption technique, and EPO was measured with a modified radioimmunoassay.. PbB in the subjects exposed to lead ranged from 0.796 to 4.4 mumol/l, and PbU varied between 0.033 and 0.522 mumol/l. In subjects exposed to lead with PbB > or = 2.896 mumol/l (n = 7), BFU-E cells were significantly reduced (p < 0.001) whereas the reduction in CFU-GM cells was only of borderline significance (p = 0.037) compared with the age matched controls (n = 20). The CFU-GEMM cells remained unchanged. Furthermore, BFU-E and CFU-GM cells were reduced in a dose dependent fashion, with increasing PbB or PbU, respectively. In the subjects exposed to lead EPO was in the normal range and did not increase in the presence of anaemia induced by lead. No correlations existed between EPO and PbB, PbU, or progenitor cells.. The data suggest new aspects of lead induced anaemia besides the currently acknowledged shortened life span of erythrocytes and inhibition of haemoglobin synthesis. Two additional mechanisms should be considered: the reduction of BFU-E cells, and inappropriate renal EPO production in the presence of severe exposure to lead, which would lead to an inadequate maturation of BFU-E cells.

Topics: Adult; Anemia; Colony-Forming Units Assay; Dose-Response Relationship, Drug; Erythroid Precursor Cells; Erythropoietin; Humans; Lead; Lead Poisoning; Male; Metallurgy; Middle Aged; Occupational Diseases

Lead (Pb) poisoning has numerous effects on the erythropoietic system, but the precise mechanism whereby high dose exposure causes anemia is not entirely clear. We previously reported that Pb exposure is associated with depressed serum erythropoietin (EPO) in pregnant women residing in a Pb mining town and in a nonexposed town in Kosovo, Yugoslavia. In a prospective study, we tested the hypothesis that blood Pb concentration (BPb) may be associated with depressed EPO in children. BPb, hemoglobin (Hgb), and serum EPO were measured at ages 4.5, 6.5, and 9.5 years in 211, 178, and 234 children, respectively. At 4.5 years of age, mean BPbs were 38.9 and 9.0 microg/dl in the exposed and nonexposed towns, respectively; BPbs gradually declined to 28.2 and 6.5 microg/dl, respectively, by age 9.5 years. No differences were found in Hgb at any age. At age 4. 5 years, a positive association between BPb and EPO (beta = 0.21; p = 0.0001), controlled for Hgb, was found. The magnitude of this association declined to 0.11 at age 6.5 years (p = 0.0103) and 0.03 at age 9.5 years (p = 0.39). These results were confirmed using repeated measures analyses. We concluded that in Pb-exposed children, the maintenance of normal Hgb requires hyperproduction of EPO. With advancing age (and continuing exposure), this compensatory mechanism appears to be failing, suggesting a gradual loss of renal endocrine function due to Pb exposure.

Topics: Age Factors; Child; Child, Preschool; Environmental Exposure; Erythrocytes; Erythropoietin; Female; Hematopoiesis; Hemoglobins; Humans; Kidney; Lead Poisoning; Male

The aim of the study was to test the hypothesis that high blood lead levels are associated with depressed serum erythropoietin concentrations in workers occupationally exposed to lead. The results in exposed workers and in a control group of unexposed subjects were compared. Blood lead values were < or = 20 micrograms/dl in unexposed subjects and > or = 30 micrograms/dl in exposed subjects. The two groups of exposed workers and the control population were matched for sex and age. Hemoglobin levels were not affected by blood lead values and did not differ significantly between the three groups. The two-tailed, nonparametric Mann-Whitney U-test was used to compare unpaired groups. The Spearman rank correlation test was used to evaluate the dose-effect relationship between Pb and EPO. The analysis of the data indicate that erythropoietin values are significantly lower in exposed subjects than a controls. However no correlation was demonstrated between blood lead concentrations and erythropoietin in any group.

Topics: Adult; Case-Control Studies; Ceramics; Environmental Monitoring; Erythropoietin; Glass; Hemoglobins; Humans; Lead Poisoning; Male; Middle Aged; Occupational Diseases; Statistics, Nonparametric

The second part of this study deals with blood lead (PbB) levels in 541 pregnant women and 351 nonpregnant women of childbearing age residing in the health center's catchment area. Each blood sample was analyzed for erythroprotoporphyrin (EP) and PbB. Comparisons of these data were made with national data on women of childbearing age and with children in our catchment area, as well as with children nationally. Mean PbB and prevalence rates at greater than or equal to 10 and greater than or equal to 15 micrograms/dL were higher in the nonpregnant women of the catchment area than in the pregnant women. For comparison with women nationally, the data on these two groups were combined because national data did not clearly distinguish between pregnant and nonpregnant women. The women in the catchment area showed mean PbB and prevalence rates at the two ranges noted above that were not only higher than in white women but also generally higher than in black women nationally. Thus, this rank order was similar to that reported earlier for children. The comparisons between women and children living in the same environment showed that the children have significantly higher mean PbBs and prevalence rates at the two ranges than the women. The physiological and environmental bases for these differences are discussed. As in the study on children, the EP is also not adequate as a screening procedure for identifying women with PbB levels greater than or equal to 25 and greater than or equal to 15 micrograms/dL.

Topics: Adolescent; Adult; Child, Preschool; Community Health Centers; Erythropoietin; Female; Humans; Infant; Lead; Lead Poisoning; Pregnancy; Prevalence; Sensitivity and Specificity; United States

Topics: Anemia; Animals; Chronic Disease; Dose-Response Relationship, Drug; Erythropoietin; Hypoxia; Kidney; Lead; Lead Poisoning; Male; Rats

Topics: Anemia; Animals; Blood Transfusion; Drug Evaluation, Preclinical; Erythropoietin; Lead Poisoning; Rabbits

Topics: Animals; Dactinomycin; Erythropoiesis; Erythropoietin; Female; Hepatectomy; Hypoxia; Iron Radioisotopes; Lead Poisoning; Liver; Mice; Nephrectomy; Polycythemia; Rats

Topics: Animals; Bone Marrow; Cell Migration Inhibition; Erythrocyte Count; Erythropoiesis; Erythropoietin; Hemoglobins; Lead Poisoning; Leukocytes; Rabbits; Reticulocytes

Topics: Animals; Cell Differentiation; Embryo, Mammalian; Erythrocyte Aging; Erythrocytes; Erythropoiesis; Erythropoietin; Female; Heme; Hypoxia; Iron Isotopes; Lead; Lead Poisoning; Mice

Topics: Anemia, Sideroblastic; Animals; Ascorbic Acid; Cobalt; Erythropoiesis; Erythropoietin; Humans; Lead Poisoning; Porphyrias; Porphyrins; Rats

Topics: Animals; Diet; Dogs; Erythropoietin; Humans; Kidney Neoplasms; Lead Poisoning; Mice; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Nitrosamines; Rats