|Environment & Health||ISSN: 2077-7477 eISSN: 2077-7485
No: 2 (91) - June, 2019 - Pages: 60-64
Features of the modern pesticides modes of action on the thyroid gland functionality (review)
Antonenko A.M.1, Vavrinevych O.P.1, Korshun M.M.1, Omelchuk S.T.1
1 O.O. Bohomolets National Medical University, Kyiv
A large number of xenobiotics, entering the human body from the environment, may disrupt normal functioning and contribute to the development of various diseases of the thyroid gland.
The purpose of our work was expert-analytical study of pesticides (as chemical environmental factor) mechanisms of action on the functioning of the thyroid gland.
Materials and methods. For the review we have selected a group of herbicides (triketones, benzoilpyrazole, oxazoles, bicyclooctenones), fungicides (pyrazolecarboxamides), insecticides (tetram and tetraic acids derivatives). The methods of empirical and theoretical research of scientific information.
Results and discussion. The pesticides selected for review influence on the thyroid gland at the peripheral level, interfering with the metabolism of thyroid hormones. Thus, fungicides-pyrazolecarboxamides, inducing the monooxygenase system enzymes of liver, lead to an increased degradation of thyroxine, an increase synthesis of thyroid stimulating hormone of the pituitary gland in the feedback mechanism, which, in turn, leads to hypertrophy of the thyroid gland.
With inhibition of the 4-HPPD enzyme by herbicides, the main enzyme that catalyzes tyrosine transformation became tyrosine aminotransferase (TAT). Since the reaction with TAT is reverse, the concentration of tyrosine in blood is significantly increased. Tyrosinaemia leads to development of eye damages and thyroid gland hypertrophy.
Investigated insecticides have polytropic action on the thyroid gland. They combine the induction of microsomal enzymes with stimulation of the thyroid gland, 4-HPPD inhibition with eye damage, which is manifested only in rats.
It is worth noting when extrapolating such results receiving on animals, it is necessary to take into account the peculiarities of metabolic processes and the initial level of thyroid hormones in human and experimental animals organism.
Conclusion. The analysis of pesticides mechanisms of action on the thyroid gland allowed to establish two main ways of its hypertrophy development - inhibition of hydroxypyruvate transformation and activation of the monooxygenase system in the liver.
thyroid gland, mode of action, pesticides