Portal de Periódicos da CAPES

Artigo Produção Nacional Revisado por pares

BIBTEX RIS

Evidence for changes in the tachyphylactic property of recombinant angiotensin II AT1 receptor expressed in CHO cells

2002; Elsevier BV; Volume: 439; Issue: 1-3 Linguagem: Inglês

10.1016/s0014-2999(01)01490-x

1879-0712

Lucimar Pereira de França, Silvana Aparecida Alves Corrêa, Ana Maria Barbosa, Alice T. Ferreira, Sang Won Han, Suma I. Shimuta, Antonio C.M. Paiva,

Mast cells and histamine

The manifestation of tachyphylaxis to angiotensin II in Chinese hamster ovary (CHO) cells expressing the rat angiotensin II AT1 receptor was investigated. The cells were transfected with a cDNA fragment containing the complete coding region of the angiotensin II AT1A receptor gene, as well as 56 bp of its 3′- and 52 bp of its 5′-untranslated regions. These cells (CHO-AT1) responded to angiotensin II by increases in intracellular Ca2+ concentration and inositol phosphate turnover, which were inhibited upon repeated administrations, characterizing the tachyphylaxis phenomenon. In contrast to smooth muscle cells, which are rendered tachyphylactic to angiotensin II but not to [2-lysine]angiotensin II ([Lys2]angiotensin II), this analogue induced responses in CHO-AT1 cells that were also inhibited upon repeated administrations. A smooth muscle cell line, which showed tachyphylaxis only to angiotensin II, became tachyphylactic also to [Lys2]angiotensin II after transfection with the angiotensin II AT1 receptor gene. Our findings suggest that posttranscriptional control directed by the 3′- or the 5′-untranslated regions in the angiotensin II AT1 receptor gene may play a role in modulating the signal transduction pathways involved in the mechanism of angiotensin II tachyphylaxis.