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Volledig artikel met aanbevelingen > met onder ander medewerking van het
Erasmus Centrum in Rotterdam en het VU medisch centrum in Amsterdam

THYROID
Volume 24, Number 1, 2014 ª American Thyroid Association
DOI: 10.1089/thy.2013.0109

American Thyroid Association Guide to Investigating Thyroid Hormone Economy and Action in Rodent and Cell Models

1Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, Florida.
2Department of Pharmacy Practice and Pharmaceutical Sciences, College of Pharmacy, University of Minnesota Duluth, Duluth, Minnesota.
3Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes
of Health, Bethesda, Maryland.
4Department of Physiology and Neurobiology, Dartmouth Medical School, Lebanon, New Hampshire.
5Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
6Division of Endocrinology, Metabolism, and Molecular Medicine, and Center for Genetic Medicine, Feinberg School of Medicine,
Northwestern University, Chicago, Illinois.
7Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois.
8Institute of Biomedical Investigation (IIB), Spanish National Research Council (CSIC) and Autonomous University of Madrid, Madrid, Spain.
9Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
10Department of Biological Sciences, Minnesota State University, Mankato, Minnesota.
11Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
12Department of Medicine, Imperial College London, Hammersmith Campus, London, United Kingdom.
*Chair; all other authors are listed in alphabetical order.

Background:
An in-depth understanding of the fundamental principles that regulate thyroid hormone homeostasis
is critical for the development of new diagnostic and treatment approaches for patients with thyroid disease.

Summary:
Important clinical practices in use today for the treatment of patients with hypothyroidism, hyperthyroidism,
or thyroid cancer are the result of laboratory discoveries made by scientists investigating the most
basic aspects of thyroid structure and molecular biology.

In this document, a panel of experts commissioned by the American Thyroid Association makes a series of
recommendations related to the study of thyroid hormone economy and action.
These recommendations are intended to promote standardization of study design, which should in turn increase
the comparability and reproducibility of experimental findings.

Conclusions:
It is expected that adherence to these recommendations by investigators in the field will facilitate
progress towards a better understanding of the thyroid gland and thyroid hormone dependent processes


FIG. 8.
Supply and metabolism of thyroid hormones affect negatively and positively T3-regulated genes in the brain. To
construct this figure, the authors used individual reverse transcriptase quantitative polymerase chain reaction (RT-qPCR)
data from T3-regulated genes to calculate the fold change relative to the wild-type (WT) values, and plotted the Log2FC (fold
change) to make the results quantitatively comparable. The data were represented in a box-and-whiskers (5%–95%) plot.
Statistical significance between each group and the WT was calculated by one-way ANOVA. For the positive genes,
F5,537 = 272, p < 0.0001. For the negative genes, F5,400 = 145, p < 0.0001. *p < 0.05; **p < 0.01; ***p < 0.001. Reproduced with permission
from Hernandez et al. (492).


RECOMMENDATION 5b
Assays for measuring circulating T4 and T3 are best performed using serum rather than plasma, since fibrin formation
affects pipetting, and additives such as heparin may directly interfere with free hormone determination.

Commentary.
Frequent blood samples can be obtained during the course of an experiment if limited to approximately
10% of the total volume every 2–4 weeks and 1% every 24 hours. Serum can be stored at -20C for long time periods.
The use of anesthesia may have variable effects on thyroid hormone levels, and each investigator should evaluate potential
effects in their system with the anesthetic they are using.
Serum T3 and T4 exhibit minimal circadian variations along day–night cycles;
these could be taken into account depending on the timing of sample collection.
Serum samples with milky aspect from lactating dams or from their pups can give erroneous results due to their high lipid content.
In these cases extraction of the serum and removal of the lipids using chloroform is advisable (67).

RECOMMENDATION 5c
Determinations of free iodothyronine indexes (FT4I and T3I) in the serum can be achieved by measurement of the
total serum hormone concentration and the serum iodothyronine binding capacity using one of the resin or charcoal methods.

Commentary.
The existence of proteins in the serum that reversibly bind thyroid hormone establishes two pools of circulating T4 and T3 (i.e., prote etc.etc.



Het volledige artikel:
http://online.liebertpub.com/doi/pdf/10 ... .2013.0109