Development of Radiometric Assays for Quantification of Enzyme Activities of the Key Enzymes of Thyroid Hormones Metabolism

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F14%3A00107116" target="_blank" >RIV/00216224:14310/14:00107116 - isvavai.cz</a>

Alternative codes found

RIV/67985823:_____/14:00431267

Result on the web

<a href="http://www.biomed.cas.cz/physiolres/pdf/63%20Suppl%201/63_S133.pdf" target="_blank" >http://www.biomed.cas.cz/physiolres/pdf/63%20Suppl%201/63_S133.pdf</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Development of Radiometric Assays for Quantification of Enzyme Activities of the Key Enzymes of Thyroid Hormones Metabolism

Original language description

We newly elaborated and adapted several radiometric enzyme assays for the determination of activities of the key enzymes engaged in the biosynthesis (thyroid peroxidase, TPO) and metabolic transformations (conjugating enzymes and iodothyronine deiodinases, IDs) of thyroid hormones (THs) in the thyroid gland and in peripheral tissues, especially in white adipose tissue (WAT). We also elaborated novel, reliable radiometric methods for extremely sensitive determination of enzyme activities of IDs of types 1, 2 and 3 in microsomal fractions of different rat and human tissues, as well as in homogenates of cultured mammalian cells. The use of optimized TLC separation of radioactive products from the unconsumed substrates and film-less autoradiography of radiochromatograms, taking advantage of storage phosphor screens, enabled us to determine IDs enzyme activities as low as 10(-18) katals. In studies of the interaction of fluoxetine (Fluox) with the metabolism of THs, we applied adapted radiometric enzyme assays for iodothyronine sulfotransferases (ST) and uridine 5'-diphosphoglucuronyltransferase (UDP-GT). Fluox is the most frequently used representative of a new group of non-tricyclic antidepressant drugs - selective serotonin re-uptake inhibitors. We used the elaborated assays for quantification the effects of Fluox and for the assessment of the degree of potential induction of rat liver ST and/or UDP-GT enzyme activities by Fluox alone or in combination with T-3. Furthermore, we studied possible changes in IDs activities in murine adipose tissue under the conditions that promoted either tissue hypertrophy (obesogenic treatment) or involution (caloric restriction), and in response to leptin, using our newly developed radiometric enzyme assays for IDs. Our results suggest that deiodinase D1 has a functional role in WAT, with D1 possibly being involved in the control of adipose tissue metabolism and/or accumulation of the tissue. Significant positive correlation between specific enzyme activity of D1 in WAT and plasma leptin levels was found. The newly developed and adapted radiometric enzyme assays proved to be very useful tools for studies of factors modulating THs metabolism, not only in model animals but also in clinical studies of human obesity.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

30105 - Physiology (including cytology)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2014

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physiological research

ISSN

0862-8408

e-ISSN

1802-9973

Volume of the periodical

63

Issue of the periodical within the volume

2014

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

8

Pages from-to

„S133“-„S140“

UT code for WoS article

000332073100011

EID of the result in the Scopus database

2-s2.0-84897625884