Data/hora: 05/06/2024 10:24:48

Provedor de dados: 	54	
País: 	Brazil	
Título: 	Prolactin inhibits auto- and cross-induction of thyroid hormone and estrogen receptor and vitellogenin genes in adult Xenopus (Amphibia) hepatocytes	
Autores: 	Rabelo,Elida M.L.; Tata,Jamshed R.	
Data: 	1997-12-01	
Ano: 	1997	
Resumo: 	It is well known that virtually every tissue of the amphibian larvae is highly sensitive to the mutually antagonistic actions of thyroid hormone (TH) and prolactin (PRL), but it is not known if adult amphibian tissues respond similarly to these two hormones. We have previously shown that very low doses of triiodothyronine (T3) rapidly and strongly potentiate the activation of silent vitellogenin (Vit) genes by estrogen (E2) and the autoinduction of estrogen receptor (ER) transcripts in primary cultures of adult Xenopus hepatocytes. This response to T3 is accompanied by the upregulation of thyroid hormone receptor &lt;FONT FACE="Symbol"&gt;b&lt;/FONT&gt; (TR&lt;FONT FACE="Symbol"&gt;b&lt;/FONT&gt;) mRNA. Using Northern blot and RNase protection assays, we now show that ovine PRL added for 12 h along with 2 x 10-9 M T3 will completely prevent potentiation of E2 induction of Vit mRNA in primary cultures of adult Xenopus hepatocytes. PRL also abolished the auto-upregulation of TR&lt;FONT FACE="Symbol"&gt;b&lt;/FONT&gt; mRNA and the cross-activation of autoinduction of ER mRNA. Thus, we show for the first time that the anti-TH action of PRL that is manifested in Xenopus tadpole tissues during metamorphosis is retained in adult liver, and suggest that the mutually antagonistic actions of the two hormones may be brought about by similar molecular mechanisms in larval and adult amphibian tissues	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84551997000400010	
Editor: 	Sociedade Brasileira de Genética	
Relação: 	10.1590/S0100-84551997000400010	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Genetics  v.20 n.4 1997	
Fonte: 	info:eu-repo/semantics/openAccess