T3 acutely increases GH mRNA translation rate and GH secretion in hypothyroid rats

Autor(es)

da Silva, F. Goulart ^[1] ; Giannocco, G. ^[1] ; Luchessi, A. D. ^[1] ; Curi, R. ^[1] ; Nunes, M. T. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Physiol & Biophys, Inst Biomed Sci, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular and Cellular Endocrinology; v. 317, n. 1-2, p. 1-7, APR 12 2010.
• Citações Web of Science: 16

Resumo

Cytoskeleton controls the stability of transcripts, by mechanisms that involve mRNAs and eEF1A attachment to it. Besides, it plays a key role in protein synthesis and secretion, which seems to be impaired in somatotrophs of hypothyroid rats, whose cytoskeleton is disarranged. This study investigated the: eEF1A and GH mRNA binding to cytoskeleton plus GH mRNA translation rate and GH secretion, in sham-operated and thyroidectomized rats treated with T3 or saline, and killed 30 min thereafter. Thyroidectomy reduced: (a) pituitary F-actin content, and eEF1A plus GH mRNA binding to it; (b) GH mRNA recruitment to polysome; and (c) liver IGF-1 mRNA expression, indicating that GH mRNA stability and translation rate, as well as GH secretion were impaired. T3 acutely reversed all these changes, which points toward a nongenomic action of T3 on cytoskeleton rearrangement, which might contribute to the increase on GH mRNA translation rate and GH secretion. (C) 2009 Elsevier Ireland Ltd. All rights reserved. (AU)

• Processo FAPESP: 06/61713-0 - Acoes nao genomicas dos hormonios tireoideanos na hipofise de ratos: repercussoes na sintese e secrecao de hormonio do crescimento (gh) e tireotrofico (tsh).
• Beneficiário: Maria Tereza Nunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular