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Modulation of pituitary response by dietary lipids and throughout a temperature fluctuation challenge in Gilthead Sea Bream
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Orientador(es)
Resumo(s)
Low temperatures provoke drastic reductions in gilthead sea bream (Sparus aurata) activity
and nourishment, leading to growth arrest and a halt in production. However, scarce data exist
concerning the implications of central core control during the cold season. The aim of this work was
to study the effects of low temperature and recovery from such exposure on the pituitary activity of
sea bream juveniles fed 18% or 14% dietary lipid. A controlled indoor trial was performed to simulate
natural temperature fluctuation (22 ◦C to 14 ◦C to 22 ◦C). Meanwhile, we determined the regulatory
role of the pituitary by analyzing the gene expression of some pituitary hormones and hormone
receptors via qPCR, as well as plasma levels of thyroidal hormones. In response to higher dietary
lipids, hormone pituitary expressions were up-regulated. Induced low temperatures and lower
ingesta modulated pituitary function up-regulating GH and TSH and thyroid and glucocorticoid
receptors. All these findings demonstrate the capacity of the pituitary to recognize both external
conditions and to modulate its response accordingly. However, growth, peripheral tissues and
metabolism were not linked or connected to pituitary function at low temperatures, which opens an
interesting field of study to interpret the hypothalamus–pituitary–target axis during temperature
fluctuations in fish.
Descrição
Palavras-chave
Low temperatures Pituitary hormones Sparus aurata Temperature recovery Thyroxine Triiodothyronine
Contexto Educativo
Citação
Editora
MDPI