Effect of angiotensin-(1-7) on jejunal absorption of water in rats.
The effect of angiotensin-(1-7) on jejunal water absorption in rats was investigated. The jejunal sac of anesthetized rats was filled with two ml of tyrode solution containing 3.7 MBq of tritiated water. A femoral vein was cannulated for administration of peptides and drugs. Infusion of Ang-(1-7) at the dose of 0.7 ng/kg.min produced a significant increase in jejunal water absorption compared to control (32% increase). The Ang-(1-7) antagonist A-779 abolished the effect of Ang-(1-7) on water absorption. A reduction of the Ang-(1-7) effect was also produced by treatment with the AT(1) receptor antagonist, losartan or the AT(2) receptor antagonist, PD123.177. The increase in jejunal water absorption produced by Ang-(1-7) was blocked by the nitric oxide synthase inhibitor, L-NAME and by indomethacin. These data suggest that the effect of Ang-(1-7) on the jejunal loop is mediated by activation of a multiple angiotensin receptors and/or by an atypical angiotensin receptor. Furthermore, the effect of Ang-(1-7) on jejunal water absorption is mediated by nitric oxide and by a cyclooxygenase-dependent mechanism.
Borges
E L
EL
Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, MG, Belo Horizonte, Brazil. borgesel@mono.icb.ufmg.br
Cabral
B M
BM
Braga
A A
AA
Neves
M J
MJ
Santos
R A S
RA
Rogana
E
E
D000803:Angiotensin I / Q000494:pharmacology*; D000804:Angiotensin II / Q000037:antagonists & inhibitors; D000818:Animals; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000378:metabolism / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010446:Peptide Fragments / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011485:Protein Binding; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014867:Water / Q000737:chemistry / Q000378:metabolism*
D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D007093:Imidazoles; D010446:Peptide Fragments; D011725:Pyridines; D014867:Water; D000804:Angiotensin II; C066253:PD 123177; D009569:Nitric Oxide; D000803:Angiotensin I; D019001:Nitric Oxide Synthase; D011451:Prostaglandin-Endoperoxide Synthases; C118790:angiotensin I (1-7); D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin