Exposure to monocrotophos pesticide causes disruption of the hypothalamic–pituitary–thyroid axis in adult male goldfish (Carassius auratus)

Toxicological effects of clofibric acid and diclofenac on plasma thyroid hormones of an Indian major carp, Cirrhinus mrigala during short and long-term exposures

“…Leatherland and Farbridge (1992) suggested that lower level of plasma T 3 may be a result of an inability of the organism to produce plasma T 3 optimum level or it may have been the result of chemical interaction along the hypothalamic-pituitary-ovarian axis (Ruby et al, 1993). A decrease in plasma T 3 levels is generally due to a drop in thyroidal T 4 production and secretion and/or changes in peripheral THs metabolism (Li et al, 2008) or changes in peripheral TH deiodination or metabolism (Zhang et al, 2013). Iodothyronine deiodinases play vital roles in the mechanism of TH biotransformation in extra-thyroidal tissues (Zhang et al, 2013).…”

“…A decrease in plasma T 3 levels is generally due to a drop in thyroidal T 4 production and secretion and/or changes in peripheral THs metabolism (Li et al, 2008) or changes in peripheral TH deiodination or metabolism (Zhang et al, 2013). Iodothyronine deiodinases play vital roles in the mechanism of TH biotransformation in extra-thyroidal tissues (Zhang et al, 2013). Furthermore, in fish, deiodinase mRNA levels are highly sensitive to numerous xenobiotics (Li et al, 2009(Li et al, , 2011Picard-Aitken et al, 2007;Yu et al, 2010).…”

“…Furthermore, in fish, deiodinase mRNA levels are highly sensitive to numerous xenobiotics (Li et al, 2009(Li et al, , 2011Picard-Aitken et al, 2007;Yu et al, 2010). The reduction in the levels of circulating T 3 in the monocrotophos (0.01 and 0.10 mg L −l ) exposed fish may also be due to higher stimulated metabolism of T 3 (Zhang et al, 2013). In general, a decline in plasma T 3 levels is mostly due to a drop in thyroidal T 4 production and secretion.…”

“…In fish, the thyroid endocrine system is controlled primarily by the hypothalamic-pituitary-thyroid (HPT) axis, which play an important role in regulation of differentiation, migration, sexual maturation, growth, metabolism, osmoregulation and salinity adaptation (Matty, 1985;Griffin, 2000;Power et al, 2001;Liu and Chan, 2002;Crane et al, 2004;Eales, 2006;Jugan et al, 2010;Yan et al, 2012;Wang et al, 2013;Murk et al, 2013). In fish, most of the plasma THs are bound to transthyretin (TTR), a specific TH transport protein and only free hormones can enter into target cells to elicit a response (Power et al, 2000;Zhang et al, 2013).…”

Induction of DNA base damage and strand breaks in peripheral erythrocytes and the underlying mechanism in goldfish (Carassius auratus) exposed to monocrotophos

“…Test compound concentrations were maintained in a semi-static manner (half water renewal daily), and quantification of monocrotophos in exposure solutions was analyzed by the ultra-performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS). Monocrotophos was undetected in the control tanks, while the analyzed concentrations (mean ± standard deviation; and % analyzed/nominal) in the test solutions were 0.001 ± 0.0001 (25 %), 0.009 ± 0.0004 (22.5 %), and 0.091 ± 0.0062 mg/L (22.75 %) (Zhang et al 2013). The concentrations mentioned in the following referred to the nominal monocrotophos pesticide values.…”