An optimized radioimmunoassay for quantification of total serum thyroxine (T4) in fetal, neonatal, and pregnant rats.

Katherine L O'Shaughnessy, Michelle G Hotchkiss, Angela K Buckalew, Ashley S Murr, Mary E Gilbert, Tammy E Stoker

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In one paragraph

Article in Neurotoxicology and teratology. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it

0cells of the map it votes in

0citing papers in PubMed

0.2field-weighted citation impact, top 41% of its field

1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed, 1 citations in OpenAlex.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 1 institution in 1 country.

Katherine L O'ShaughnessyNeurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.

Michelle G HotchkissNeurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.

Angela K BuckalewNeurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.

Ashley S MurrNeurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.

Mary E GilbertNeurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.

Tammy E StokerNeurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA. Electronic address: stoker.tammy@epa.gov.

Environmental Protection Agency · US

Funding

Intramural EPA EPA999999

6 · The paper itself

Abstract

Identifying xenobiotics that interrupt the thyroid axis has significant public health implications, given that thyroid hormones are required for brain development. As such, some developmental and reproductive toxicology (DART) studies now require or recommend serum total thyroxine (T4) measurements in pregnant, lactating, and developing rats. However, serum T4 concentrations are normally low in the fetus and pup which makes quantification difficult. These challenges can be circumvented by technologies like mass spectrometry, but these approaches are expensive and not always widely available. To demonstrate the feasibility of measuring T4 using a commercially available assay, we examine technical replicates of rat serum samples measured both by liquid chromatography mass spectrometry (LC/MS/MS) and radioimmunoassay (RIA). These samples were obtained from rats on gestational day 20 (dams and fetuses) or postnatal day 5 (pups), following maternal exposure to the goitrogen propylthiouracil (0-3 ppm) to incrementally decrease T4. We show that with assay modification, it is possible to measure serum T4 using low sample volumes (25-50 μL) by an RIA, including in the GD20 fetus exposed to propylthiouracil. This proof-of-concept study demonstrates the technical feasibility of measuring serum T4 in DART studies.

Indexed as

ThyroxineTriiodothyronineAnimalsFemaleFetusLactationPregnancyPropylthiouracilRadioimmunoassayRatsTandem Mass SpectrometryPropylthiouracilThyroxineTriiodothyronineDevelopmental and reproductive toxicology (DART)Endocrine disruptionMass spectrometryRadioimmunoassay (RIA)Thyroid hormones

Identifiers

PMID37777095

DOI10.1016/j.ntt.2023.107303

PMCPMC11884239

OpenAlexW4387125413

What OpenQuestion holds

Textmetadata

Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.