Estudo da distribuição do transportador da hormona tiroxina - transretina - em dourada, Sparus aurata (Linnaeus, 1758)

• Autor(a) principal: Charrão, Adelaide da Conceição Dimas Henrique
• Data de Publicação: 1998
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Texto Completo: http://hdl.handle.net/10400.1/6754
• topic: Transretina; Tiroxina; Peixes; Dourada; Sparus aurata; Aquacultura

Transthyretin (TTR) is one of three thyroxine binding proteins found in the serum of higher animais. It has been shown to be synthesised and secreted in the choroid plexus of placental mammals, birds and reptiles but not in amphibians. Recently has cloned transthyretin from a sea bream liver cDNA library (Santos & Power, 1998). The objective of the present study was to determine the distribution of TTR in sea bream and study its regulation thyroid hormone. Ti and T4 (0,1 mg/g body weight) or saline was administered to sea bream by a single intraperitoneal injection. At 6h, I2h and 24h after injection treated and controls fish were killed and tissue removed. Expression of TTR was determined by RT-PCR, using homologous primers coupled with Southern blotting. The identity of PCR products was also confirmed by partial sequencing. TTR was expressed in liver, brain, heart, gill and gut and undetectable in kidney and muscle. Treatment with T3 e T4 changed the levei of expression of TTR in tissue. During the timescale studied there was a different up-regulation ofTTR expression by T4and T3 in liver and brain.