Data/hora: 10/06/2024 08:08:22

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Effect of selective angiotensin antagonists on the antidiuresis produced by angiotensin-(1-7) in water-loaded rats	
Autores: 	Baracho,N.C.V.; Simões-e-Silva,A.C.; Khosla,M.C.; Santos,R.A.S.	
Data: 	1998-09-01	
Ano: 	1998	
Palavras-chave: 	Renin-angiotensin system; Angiotensin receptors; Antidiuresis; Losartan; A-779; Ang-(1-7).	
Resumo: 	In the present study we evaluated the nature of angiotensin receptors involved in the antidiuretic effect of angiotensin-(1-7) (Ang-(1-7)) in water-loaded rats. Water diuresis was induced in male Wistar rats weighing 280 to 320 g by water load (5 ml/100 g body weight by gavage). Immediately after water load the rats were treated subcutaneously with (doses are per 100 g body weight): 1) vehicle (0.05 ml 0.9% NaCl); 2) graded doses of 20, 40 or 80 pmol Ang-(1-7); 3) 200 nmol Losartan; 4) 200 nmol Losartan combined with 40 pmol Ang-(1-7); 5) 1.1 or 4.4 nmol A-779; 6) 1.1 nmol A-779 combined with graded doses of 20, 40 or 80 pmol Ang-(1-7); 7) 4.4 nmol A-779 combined with graded doses of 20, 40 or 80 pmol Ang-(1-7); 8) 95 nmol CGP 42112A, or 9) 95 nmol CGP 42112A combined with 40 pmol Ang-(1-7). The antidiuretic effect of Ang-(1-7) was associated with an increase in urinary Na+ concentration, an increase in urinary osmolality and a reduction in creatinine clearance (CCr: 0.65 ± 0.04 ml/min vs 1.45 ± 0.18 ml/min in vehicle-treated rats, P&amp;lt;0.05). A-779 and Losartan completely blocked the effect of Ang-(1-7) on water diuresis (2.93 ± 0.34 ml/60 min and 3.39 ± 0.58 ml/60 min, respectively). CGP 42112A, at the dose used, did not modify the antidiuretic effect of Ang-(1-7). The blockade produced by Losartan was associated with an increase in CCr and with an increase in sodium and water excretion as compared with Ang-(1-7)-treated rats. When Ang-(1-7) was combined with A-779 there was an increase in CCr and natriuresis and a reduction in urine osmolality compared with rats treated with Ang-(1-7) alone. The observation that both A-779, which does not bind to AT1 receptors, and Losartan blocked the effect of Ang-(1-7) suggests that the kidney effects of Ang-(1-7) are mediated by a non-AT1 angiotensin receptor that is recognized by Losartan.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000900016	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X1998000900016	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.31 n.9 1998	
Fonte: 	info:eu-repo/semantics/openAccess