Comparison of the mouse spleen cell assay and a radioimmunoassay for the measurement of serum erythropoietin

Lappin, T. R. J.; Elder, G. E.; Taylor, T.; McMullin, Mary Frances; Bridges, J. M.

doi:10.1111/j.1365-2141.1988.tb02443.x

Cited by 30 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This probably reflects the influence of the impurities in these materials on the cultured assay cells, which may be greatest for CFUe assays because both rates of growth and differentia¬ tion are measured. These in-vitro bioassays are there¬ fore not readily applicable to the assay of serum EPO without some prior extraction procedure (Lappin, Elder, Taylor et al 1988;Wognum, Lam, Goudsmit & Krystal, 1990).…”

Section: Comparisons Of Epo Assay Methodsmentioning

confidence: 99%

The International Standard for Recombinant DNA-derived Erythropoietin: collaborative study of four recombinant DNA-derived erythropoietins and two highly purified human urinary erythropoietins

Storring

Das²

1992

Journal of Endocrinology

View full text Add to dashboard Cite

The International Standard (IS) for Recombinant DNA-Derived (rDNA) Erythropoietin (EPO) (in ampoules coded 87/684) and three other rDNA EPO preparations in ampoules coded 87/690, 87/696 and 88/574 respectively, were compared with two preparations of highly purified human urinary (HU) EPO and the 2nd International Reference Preparation of Human Urinary Erythropoietin for Bioassay (2nd IRP) by 26 laboratories in 11 countries using a wide range of in-vivo and in-vitro bioassays and immunoassays. These EPO preparations were also compared by electrophoresis and isoelectric focusing. Estimates of EPO content in terms of the 2nd IRP by all in-vivo bioassay methods gave combined unweighted geometric means (with 95% fiducial limits) of: 86 (75-99) IU/ampoule for the IS, 81 (70-94) IU/ampoule for 87/690, 58 (48-71) IU/ampoule for 87/696 and 120 (100-143) IU/ampoule for 88/574. Mean estimates of EPO content in terms of the 2nd IRP by in-vitro bioassays (except receptor assays) were larger than, and those by immunoassays were similar to, the mean estimates by in-vivo bioassays. The use of purified rDNA or HU EPO as standards in place of the 2nd IRP reduced the inter-laboratory variability of estimates of purified EPO preparations by in-vivo and in-vitro bioassays and by immunoassays, and reduced the variability of overall mean estimates for each of these preparations between the three types of method. The inter-laboratory variability of immunoassay estimates of human serum EPO was similar whether the 2nd IRP or one of the purified EPOs was used as standard. Significant differences in in-vivo and in-vitro biological, immunological and physicochemical properties were found between these four rDNA EPO preparations and between them and the HU EPO in the two purified preparations and in the 2nd IRP. There were also differences between the immunoreactivities of the two serum EPO samples included in the study, and between them and the immunoreactivities of the purified EPOs. The differences between rDNA EPOs appeared to be related to differences between the cells used for their biosynthesis, but may also be the result of differences in purification methods and of inter-batch variations. Significant differences in assay specificity were observed within each of the three general types of method. The specificity of the in-vivo bioassays was influenced by the route of hormone administration. The specificities of the mouse spleen cell in-vitro bioassays differed from that of the mouse spleen receptor-binding assay.(ABSTRACT TRUNCATED AT 400 WORDS)

show abstract

Section: Comparisons Of Epo Assay Methodsmentioning

confidence: 99%

The International Standard for Recombinant DNA-derived Erythropoietin: collaborative study of four recombinant DNA-derived erythropoietins and two highly purified human urinary erythropoietins

Storring

Das²

1992

Journal of Endocrinology

View full text Add to dashboard Cite

show abstract

“…Umbilical arterial cord blood was sampled and used to measure levels of Epo, haemoglobin, haematocrit and blood gases. Se rum was immediately separated by centrifugation and stored at -70 °C until Epo levels were estimated by radio-immunoassay [17]. Briefly, the method involved a disequilibrium assay, using l25I-labelled Epo (Amersham International PLC, Amersham, UK) and rabbit anti-Epo antibody.…”

Section: Methodsmentioning

confidence: 99%

“…Briefly, the method involved a disequilibrium assay, using l25I-labelled Epo (Amersham International PLC, Amersham, UK) and rabbit anti-Epo antibody. Batches of 20 serum samples were assayed under a protocol which required 4 days for completion [17], Blood gases and pH were measured immediately using an automated Corning blood gas analyser. Correlation coefficients were calculated by the method of differences between least squares.…”

Section: Methodsmentioning

confidence: 99%

“…Most earlier studies relied on in vivo and in vitro techniques for Epo measurement, which lack the sensitivity and specificity of recent immu nological techniques [15][16][17], The assessment of fetal asphyxia is difficult, and the value of low Apgar scores and low cord blood pH has recently been questioned [18][19][20][21], We mea sured Epo in serum from human newborn babies following Caesarean section prior to the onset of labour in an attempt to assess its value as a marker of fetal stress.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cord Blood Erythropoietin, pH, PaO<sub>2</sub> and Haematocrit following Caesarean Section before Labour

et al. 1993

View full text Add to dashboard Cite

We have investigated the relationship between erythropoietin (Epo) and pH, PaO₂ and haematocrit in 100 cord blood samples obtained at Caesarean section prior to labour. Of 82 term ( > 37 weeks) infants, 64 were appropriately grown (10^th–90th centiles), and their mean cord serum Epo and cord blood Epo was 23 ± 8 mU/ml (mean ± SD). Strong inverse correlations were found between cord serum Epo and cord blood pH (r = ––0.74; p < 0.0001), and between cord serum Epo and cord blood PaO₂ ( r = ––0.55; p < 0.0001), but not between cord serum Epo and cord haematocrit (r = 0.02; p < 0.9). For the 18 preterm babies (gestation 32.4 ± 4.1 weeks, birth weight 1,820 ± 476 g), the Epo level was 36 ± 8 mU/ml, which was not significantly greater than for the term babies. Strong inverse correlations were again found between Epo and pH (r= ––0.87; p < 0.0001) and Epo and PaO₂ (r = ––0.69; p < 0.002). Babies from complicated pregnancies (intra-uterine growth retardation, pre-eclampsia, antepartum haemorrhage, diabetes mellitus and fetal distress) tended to have higher Epo levels. Thirteen babies had Epo levels > 40 mU/ml, and 11 (85%) of these required neonatal intensive care. Cord serum Epo correlates better with oxygen tension and pH at birth than with fetal growth and haematocrit, which are measures of chronic stress to the fetus.

show abstract

“…Epo was determined by radioimmunoassay [20] with some modifications. The method uses a disequilibrium system in which the addition of the labelled antigen is delayed for 3 days after the initial mixing of the test or standard Epo solutions with the antiEpo antibody.…”

Section: Radioimmunoassay For Epomentioning

confidence: 99%

Erythropoietin production: evidence for multiple oxygen sensing pathways

Daghman¹,

Elder²,

Savage³

et al. 1999

Annals of Hematology

View full text Add to dashboard Cite

The production of erythropoietin (Epo), the glycoprotein hormone which controls red blood cell formation, is regulated by feedback mechanisms sensing tissue oxygenation. The mechanism of the putative oxygen sensor has yet to be elucidated. There is evidence that at least two pathways participate in hypoxia signal transduction. One appears to involve a specific haem protein, and a second implicates reactive oxygen species (ROS). Iron catalyses the generation of intracellular ROS and therefore alters the cellular redox state. We have investigated the effect of modulating intracellular iron content on Epo production in Hep 3B cells. Iron chelation stimulates Epo production at 20% O2 and enhances Epo production at 1% O2, but it has no additive effect on cobalt-induced Epo production. Excess molar iron inhibited Epo production in response to hypoxia, desferrioxamine (DFO) and cobalt chloride and inhibited the DFO-enhancing effect of hypoxia-induced Epo production. We found that sulphydryl oxidising agents exert a differential inhibitory effect on hypoxia-induced versus DFO-induced Epo production, providing further evidence that multiple pathways of oxygen sensing exist.

show abstract

Comparison of the mouse spleen cell assay and a radioimmunoassay for the measurement of serum erythropoietin

Cited by 30 publications

References 9 publications

The International Standard for Recombinant DNA-derived Erythropoietin: collaborative study of four recombinant DNA-derived erythropoietins and two highly purified human urinary erythropoietins

The International Standard for Recombinant DNA-derived Erythropoietin: collaborative study of four recombinant DNA-derived erythropoietins and two highly purified human urinary erythropoietins

Cord Blood Erythropoietin, pH, PaO<sub>2</sub> and Haematocrit following Caesarean Section before Labour

Erythropoietin production: evidence for multiple oxygen sensing pathways

Contact Info

Product

Resources

About