The activity of the department is twofold: services and research.
Services provided
1. Radioactivity measurements of all kinds of samples are carried out for
research workers of other departments of the Institute of Physiology as well as
other Institutes of the Academy of Sciences in the Krč area.
2. Disposal of radioactive waste produced in more than a hundred
radioisotopic laboratories of the Institutes in the Krč area.
3. Counselling and services in the field of manipulation with radioactive
materials, ordering and purchasing radioactive preparations, etc.
Research topics
Maturation of organs and tissues in human newborns, a role for thyroid
hormones and uncoupling protein 2. A clinically oriented study performed within
the scope of the grant project "Role of triiodothyronine formation in
brown adipose tissue of human neonates and molecular mechanisms" (IGA MH CR
No. Z629-3) was carried out in cooperation with the Department of Biology of
Adipose Tissue of this Institute. In this study we have characterized the
thyroid status in very pre-term infants from birth through day 14. Moreover, in
infants who died within 16 days of delivery, the thyroid status was also
correlated with metabolism of thyroid hormones in peripheral tissues (brain,
liver, kidney, different depots of adipose tissue, and skeletal muscle). In all
post mortem tissue samples activities of the three iodothyronine deiodinase
isoenzymes of type I, II, and III were detected. All activities were in liver,
and differed considerably in other tissues. Lack of correlation between the type
I 5'-deiodinase activity in liver, and plasma levels of thyroid hormones
suggested that the thyroid was the primary source of circulating
triiodothyronine. On the other hand, correlations between activity of the
deiodinases and plasma iodothyronine levels were found in brain which suggested
a complex control by the thyroid hormones of their own metabolism.
Interference of bromine from the environment with iodine metabolism in the
thyroid gland and other tissues of the rat and humans: Within the framework of
the grant projects "Biological significance of the interaction of bromine
with iodine from the standpoint of changes in their environmental concentration",
"The influence of an excess of bromine and/or iodine deficiency on the
metabolism of thyroid hormones in tissues" and "Interference of
bromide from the environment with iodine metabolism in the thyroid gland and
other tissues" we have studied mechanisms of the bromine interference with
iodine metabolism in the rat thyroid gland as a model of the action of
goitrogenic substances from the environment on risk population groups. We found
that the biological behaviour of bromine in the rat thyroid, contrary to other
organs, is not similar to the behaviour of chlorine, but rather to that of
iodine. The biological halflife of bromine in the rat thyroid (110 h) was found
to be identical with the biological halflife of iodine, and was essentially
different from the whole-body half-life of chlorine (325 h). The rat thyroid
responded very sensitively to a relatively small increase in bromine intake by a
marked decrease in the concentration ratio [I]/[Br]. In addition, we tested the
hypothesis that an enhanced bromine intake in the organism at simultaneous
insufficient iodine supply intensifies the negative consequences of
hypothyroidism and that under these conditions, bromine not only can seriously
interfere with the biosynthesis of thyroid hormones in the thyroid but it also
can influence the peripheral tissues metabolism of the thyroid hormones. From
the practical point of view, the most important finding was above all the
confirmation of the fact that the biological behaviour of bromine, and therefore
also its toxicity, depends on the state of iodine supply to the organism (i.e.,
the thyrotoxic effects of bromine compounds are more pronounced under conditions
of iodine deficiency).
The influence of antidepressant administration on thyroid hormones metabolism
in brain and other tissues: experimental studies in rats. In cooperation with
the Institute of Endocrinology, Prague and the IIIrd Clinic of Internal Medicine,
1st Medical Faculty, Charles University, Prague we carry out a study within
the scope of the grant project "The influence of antidepressant
administration on the hypothalamuspituitarythyroid axis: An experimental
study of the relationship between the thyroid function and mental disorders"
(IGA MH CR No. 42043), the aim of which is to learn about the relations between
the thyroid and mental disorders and about interactions between antidepressants
and thyroid hormones in peripheral tissues.
Publications
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