The role of angiotensin AT1 receptors in the diuretic, natriuretic, kaliuretic and blood pressure responses induced by angiotensin II activation of the median preoptic nucleus in conscious rats
MetadataShow full item record
We determined the effects of two classical angiotensin II (ANG II) antagonists, [Sar1, Ala8]-ANG II and [Sar1, Thr8]-ANG )II, and losartan (a nonpeptide and selective antagonist for the AT1 angiotensin receptors) on diuresis, natriuresis, kaliuresis and arterial blood pressure induced by ANG II administration into the median preoptic nucleus (MnPO) of male Holtzman rats weighing 250-300 g. Urine was collected in rats submitted to a water load (5% body weight) by gastric gavage, followed by a second water load (5% body weight) 1 h later. The volume of the drug solutions injected was 0.5 μl over 10-15 s. Pre-treatment with [Sar1, Ala8]-ANG II (12 rats) and [Sar1, Thr8]-ANG II (9 rats), at the dose of 60 ng reduced (13.7 ± 1.0 vs 11.0 ± 1.0 and 10.7 ± 1.2, respectively), whereas losartan (14 rats) at the dose of 160 ng totally blocked (13.7 ± 1.0 vs 7.6 ± 1.5) the urine excretion induced by injection of 12 ng of ANG II (14 rats). [Sar1, Ala8]-ANG II impaired Na+ excretion (193 ± 16 vs 120 ± 19), whereas [Sar1, Thr8]-ANG II and losartan blocked Na+ excretion (193 ± 16 vs 77 ± 15 and 100 ± 12, respectively) induced by ANG II. Similar effects induced by ANG II on K+ excretion were observed with [Sar1, Ala8]-ANG II, [Sar1, Thr8]-ANG II, and losartan pretreatment (133 ± 18 vs 108 ± 11, 80 ± 12, and 82 ± 15, respectively). The same doses as above of [Sar1, Ala8]-ANG II (8 rats), [Sar1, Thr8][-ANG-II (8 rats), and losartan (9 rats) blocked the increase in the arterial blood pressure induced by 12 ng of ANG II (12 rats) (32 ± 4 vs 4 ± 2, 3.5 ± 1, and 2 ± 1, respectively. The results indicate that the AT1 receptor subtype participates in the increases of diuresis, natriuresis, kaliuresis and arterial blood pressure induced by the administration of ANG II into the MnPO.
How to cite this document
Showing items related by title, author, creator and subject.
Núcleos de Ensino da Unesp: artigos 2009 Pinho, Sheila Zambello de ; Oliveira, José Brás Barreto de ; Gazola, Rodrigo José Cristiano ; Mazotti, Adriano César ; Molero, Camila Schimite ; Mendes, Carolina Borghi ; Mello, Denise Fernandes de ; Marques, Emilia de Mendonça Rosa ; Talamoni, Jandira Liria Biscalquini ; Silva, José Humberto Dias da et al. (Coleção PROGRAD (UNESP), 2011) [Livro]
Núcleos de Ensino da Unesp: artigos 2008 Pinho, Sheila Zambello de ; Oliveira, José Brás Barreto de ; Pontes, Sueli Rodrigues ; Almeida, Djanira Soares de Oliveira e ; Godoy, Kathya Maria Ayres de ; Rosa, Claudia de Souza ; Nunes, Julianus Araújo ; Salvador, Sérgio Azevedo ; David, Célia Maria ; Vilche Peña, Angel Fidel et al. (Coleção PROGRAD (UNESP), 2011) [Livro]
Ser e tornar-se professor: práticas educativas no contexto escolar Pinho, Sheila Zambello de ; Spazziani, Maria de Lourdes ; Mendonça, Sueli Guadelupe de Lima ; Rubo, Elisabete Aparecida Andrello ; Villarreal, Dalva Maria de Oliveira ; Duarte, Camila ; Okamoto, Mary Yoko ; Souza, Thais R. ; Garms, Gilza Maria Zauhy ; Marin, Fátima Aparecida Dias Gomes et al. (Coleção PROGRAD (UNESP), 2012) [Livro]