Characterization of the peripheral thyroid system of gilthead seabream acclimated to different ambient salinities. | - CCMAR -

Journal Article

TitleCharacterization of the peripheral thyroid system of gilthead seabream acclimated to different ambient salinities.
Publication TypeJournal Article
AuthorsRuiz-Jarabo, I, Klaren, PHM, Louro, B, Martos-Sitcha, JA, Pinto, PIS, Vargas-Chacoff, L, Flik, G, Martínez-Rodríguez, G, Power, DM, Mancera, JMiguel, Arjona, FJ
Year of Publication2016
JournalComp Biochem Physiol A Mol Integr Physiol
Volume203
Date Published2016 Aug 21
Pagination24-31
ISSN1531-4332
Abstract

Thyroid hormones are involved in many developmental and physiological processes, including osmoregulation. The regulation of the thyroid system by environmental salinity in the euryhaline gilthead seabream (Sparus aurata) is still poorly characterized. To this end seabreams were exposed to four different environmental salinities (5, 15, 40 and 55ppt) for 14days, and plasma free thyroid hormones (fT3, fT4), outer ring deiodination and Na(+)/K(+)-ATPase activities in gills and kidney, as well as other osmoregulatory and metabolic parameters were measured. Low salinity conditions (5ppt) elicited a significant increase in fT3 (29%) and fT4 (184%) plasma concentrations compared to control animals (acclimated to 40ppt, natural salinity conditions in the Bay of Cádiz, Spain), while the amount of pituitary thyroid stimulating hormone subunit β (tshb) transcript abundance remained unchanged. In addition, plasma fT4 levels were positively correlated to renal and branchial deiodinase type 2 (dio2) mRNA expression. Gill and kidney T4-outer ring deiodination activities correlated positively with dio2 mRNA expression and the highest values were observed in fish acclimated to low salinities (5 and 15ppt). The high salinity (55ppt) exposure caused a significant increase in tshb expression (65%), but deiodinase gene expression (dio1 and dio2) and activity did not change and were similar to controls (40ppt). In conclusion, acclimation to different salinities led to changes in the peripheral regulation of thyroid hormone metabolism in seabream. Therefore, thyroid hormones are involved in the regulation of ion transport and osmoregulatory physiology in this species. The conclusions derived from this study may also allow aquaculturists to modulate thyroid metabolism in seabream by adjusting culture salinity.

DOI10.1016/j.cbpa.2016.08.013
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/27557988?dopt=Abstract

Alternate JournalComp. Biochem. Physiol., Part A Mol. Integr. Physiol.
PubMed ID27557988
CCMAR Authors