Fenvalerate exposure alters thyroid hormone status in selenium- and/or iodine-deficient rats.
Considering the potential adverse effects of selenium and iodine deficiencies, and taking into account the widespread but often careless use of pyrethroid insecticides and their possible endocrine-disrupting effects, this study was undertaken to investigate the effects of fenvalerate on thyroid hormone parameters in both healthy and selenium- and/or iodine-deficient rats. Fenvalerate exposure had no effect on the TT4 levels of healthy controls but caused significant increases both in iodine deficiency (ID) and selenium plus iodine deficiency (ISeD), and a significant decrease in selenium deficiency (SeD). Dramatic increases in TT3 of all groups were observed by fenvalerate. Moreover, it caused insignificant decrease of thyroid stimulating hormone in healthy controls, no effect in SeD, and significant elevation in ID and ISeD. These results, thus, showed that the widely used pyrethroid insecticide fenvalerate has the potential to change significantly thyroid hormone parameters both in normal and deficiency states, and consequences of its thyroid status modifying effect might be of critical importance particularly in sensitive individuals and patients with thyroid dysfunction.
Giray
Belma
B
Department of Toxicology, Faculty of Pharmacy, Hacettepe University, Ankara 06100, Turkey. bgiray@hacettepe.edu.tr
Cağlayan
Aydan
A
Erkekoğlu
Pinar
P
Hincal
Filiz
F
D000818:Animals; D007455:Iodine / Q000172:deficiency*; D008297:Male; D009570:Nitriles / Q000009:adverse effects*; D011722:Pyrethrins / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar; D012643:Selenium / Q000172:deficiency*; D013961:Thyroid Gland / Q000033:anatomy & histology / Q000187:drug effects*; D013963:Thyroid Hormones / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
D009570:Nitriles; D011722:Pyrethrins; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D007455:Iodine; D012643:Selenium; D013974:Thyroxine; C017690:fenvalerate