Measurement and regulation of thyroidal status in teleost fish

Eales, J.G.; Brown, Scott

doi:10.1007/bf00043383

Cited by 203 publications

(143 citation statements)

References 244 publications

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“…Under normal conditions, the piscine thyroid gland mainly secretes the prohormone 3,5,3 0 ,5 0 -tetraiodothyronine (T 4 ). T 4 must be converted, by removal of an iodine atom, to yield the biologically active hormone 3,5,3 0 -triiodothyronine (T 3 ; Eales & Brown 1993). This reaction is catalyzed by iodothyronine deiodinases, a family of selenoenzymes, of which three types exist.…”

Section: Introductionmentioning

confidence: 99%

Effects of cortisol and thyroid hormone on peripheral outer ring deiodination and osmoregulatory parameters in the Senegalese sole (Solea senegalensis)

Arjona¹,

Vargas‐Chacoff²,

Río³

et al. 2011

Journal of Endocrinology

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The thyroid gland in fish mainly secretes the thyroid prohormone 3,5,3 0 ,5 0 -tetraiodothyronine (T 4 ), and extrathyroidal outer ring deiodination (ORD) of the prohormone to 3,5,3 0 -triiodothyronine (T 3 ) is pivotal in thyroid hormone economy. Despite its importance in thyroid hormone metabolism, factors that regulate ORD are still largely unresolved in fish. In addition, the osmoregulatory role of T 3 is still a controversial issue in teleosts. In this study, we investigated the regulation of the ORD pathway by cortisol and T 3 in different organs (liver, kidney, and gills) of Solea senegalensis and the involvement of T 3 in the control of branchial and renal Na C , K C -ATPase activity, a prime determinant of the hydromineral balance in teleosts. Animals were treated with i.p. slow-release coconut oil implants containing cortisol or T 3 . Hepatic and renal ORD activities were up-regulated in cortisol-injected animals. T 3 -treated fish showed a prominent decrease in plasma-free T 4 levels, whereas ORD activities did not change significantly. Branchial and renal Na C , K C -ATPase activities were virtually unaffected by T 3 , but were transiently up-regulated by cortisol. We conclude that cortisol regulates local T 3 bioavailability in S. senegalensis via ORD in an organ-specific manner. Unlike T 3 , cortisol appears to be directly implicated in the up-regulation of branchial and renal Na

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Section: Introductionmentioning

confidence: 99%

Effects of cortisol and thyroid hormone on peripheral outer ring deiodination and osmoregulatory parameters in the Senegalese sole (Solea senegalensis)

Arjona¹,

Vargas‐Chacoff²,

Río³

et al. 2011

Journal of Endocrinology

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“…The production of T3 in fish, in contrast, is thought to be under exclusive control of peripheral tissues, although this has not been studied recently or beyond Salmonid fishes. 125 In some contrast, the mammalian thyroid gland produces both T4 and to a lesser extent T3 under negative feedback control by the central HPT. Thus, while extrathyroidal regulation of T3 is important in all vertebrates, including for instance in the brains of developing mammals, in fish the formation and regulation of T3 may be dominated by local control in response to the needs of individual tissues rather than by T4 availability and through the central HPT axis.…”

Section: Structure and Function Of Fish Thyroidmentioning

confidence: 99%

PBDE flame retardants

Noyes

Stapleton

2014

Endocrine Disruptors

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“…The functional units for biosynthesis of the thyroid hormones in the thyroid gland are thyroid follicles composed of thyrocytes enclosing a thyroglobulin-containing colloid matrix. The hormones are synthesized under the control of a thyroid stimulating hormone (TSH) from the pituitary gland (Eales & Brown 1993). Thyroid hormones play an important role in the control of physiological events, such as metamorphosis, growth, metabolism, reproduction and osmoregulation in fish (Leatherland 1994).…”

Section: Introductionmentioning

confidence: 99%