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

1. Leux C. and Guénel P. Revue d’Epidémiologie et de Santé Publique. 2010; 58 (5): 359-367. https://doi.org/10.1016/j.respe.2010.05.005

2. Truong T., Baron-Dubourdieu D., Rougier Y. and Guenel P. Cancer Causes Control. 2010; 21 (8): 1183-1192. https://doi.org/10.1007/s10552-010-9545-2

3. Sahin A., Iskender H., Terim Kapakin K.A., Altinkaynak K., Hayirli A., Gonultas A. and Kaynar O. Brazilian Journal of Poultry Science. 2016; 18 (4): 649-654. https://doi.org/10.1590/1806-9061-2016-0299

4. State of the Science of Endocrine Disrupting Chemicals. 2013. URL : http://www.who.int/ceh/publications/endocrine/en/

5. Mode of Action of Fungicides : FRAC Classification on Mode of Action 2014. URL : http://www.frac.info

6. Antonenko А.M., Korshun М.М. and Milokhov D.S. Modern Problems of Toxicology, Food and Chemical Safety. 2015; 4 (72): 23-29 (in Ukrainian).

7. World of Herbicides Poster : HRAC Herbicide Resistance Action Committee. URL : http://www.hracglobal.com.

8. Antonenko А.M., Korshun М.М. and Milokhov D.S. Modern Problems of Toxicology, Food and Chemical Safety. 2014; 3/4 (66/67): 49-57 (in Ukrainian).

9. Antonenko A.M., Blagaia A.V., Vavrinevych O.P., Omelchuk S.T., Korshun M.M., Milokhov D.S., Pelio I.M. and Bodjar I. Journal of Pre-Clinical and Clinical Research. 2015; 9 (2): 148-153. https://doi.org/10.5604/18982395.1186496

10. Mode of Action Classification [Electronic resource]: Insecticide Resistance Action Committee. URL : https://www.sciencedirect.com/science/article/pii/S0048357514002272

11. Sarne D. Thyroid Disease Manager. 2010: 54 p.

12. Van Do N., Milo L. and Merriam G. Journal of Clinical Endocrinology. 2004; 89: 1529-1533. https://doi.org/10.1210/jc.2003-031747

13. Burger A.G. The Journal of Clinical Endocrinology & Metabolism. 2004; 89 (4): 1526-1528. https://doi.org/10.1210/jc.2004-0332

14. Zou Y., Ding G., Lou X., Zhu W., Mao G., Zhou J. and Mo Z. European Journal of Clinical Nutrition. 2013; 67: 1138-1141. https://doi.org/10.1038/ejcn.2013.173

15. Brucker-Davis F. Thyroid. 2009. Vol. 8. №. 9. URL : https://www.liebertpub.com/doi/abs/10.1089/thy.1998.8.827

16. Boas M., Feldt-Rasmussen U., Skakkebaek N.E. and Main K.M. Eurooopean Journal of Endocrinology. 2006; 154: 599-611. https://doi.org/10.1530/eje.1.02128

17. Brauer V.F., Below H., Kramer A., Fuhrer D. and Paschke R. European Journal of Endocrinology. 2006; 154: 229-235. https://doi.org/10.1530/eje.1.02076

18. Braverman L.E., He X., Pino S., Cross M., Magnani B. and Lamm S.H. J. Clin Endocrinol Metab. 2005; 90: 700-706. https://doi.org/10.1210/jc.2004-1821

19. Below H., Zollner H., Volzke H. and Kramer A. International Journal of Hygiene and Environmental Health. 2008; 211: 186-191. https://doi.org/10.1016/j.ijheh.2007.02.005

20. Navarro Silvera S.A., Miller A.B. and Rohan T.E. International Journal of Cancer. 2005; 116: 433-438. https://doi.org/10.1002/ijc.21079

21. Bianco A.C., Salvatore D. and Gereben B. Endocrine Reviews. 2002; 23 (1): 38-89. https://doi.org/10.1210/edrv.23.1.0455

22. Meek M.E., Bucher J.R. and Cohen S.M. Crit. Rev. Toxicol. 2003; 33 (6): 591-654. https://doi.org/10.1080/713608373

23. Hiroshi Matsumoto. New Discoveries in Agrocemicals. 2004; 15: 161-171. https://doi.org/10.1021/bk-2005-0892.ch015

24. Kovalchuk N.N., Bardov V.H. and Sasynovych L.M. Dovkillia ta zdorovia (Environment and Health). 2008; 3 (46): 11-18 (in Russian).

25. Grossman K. and Ehrhardt T. Pest Management Science. 2007; 65 (5): 429-439. https://doi.org/10.1002/ps.1341

26. Bretschneider Th., Benet-Buchholz J., Fischer R. and Nauen R. CHIMIA International Journal for Chemistry. 2003; 57 (11): 697-701 https://doi.org/10.2533/000942903777678588

27. Miller M.D., Crofton K.M., Rice D.C. and Zoeller R.Th. Environ Health Perspect. 2009; 117 (7): 1033-1041. https://doi.org/10.1289/ehp.0800247

28. Lamminpaa A., Pukkala E. and Teppo L. Eur. J. Clin. Pharmacol. 2002; 58: 137-141. https://doi.org/10.1007/s00228-002-0429-6

29. Knerr S. and Schrenk D. Crit. Rev. Toxicol. 2006; 36: 663-694. https://doi.org/10.1080/10408440600845304