Blockade of central angiotensin II type 1 and type 2 receptors suppresses adrenalectomy-induced NaCl intake in rats.
Removal of the adrenal glands, the main site for the synthesis of aldosterone, produces an intake of sodium that is essential for survival. Using central blockade of angiotensin II (Ang II) receptors with SarIle Ang II, previous studies have shown that this intake depends on the stimulation of the brain angiotensin system. In the present study, using intracerebroventricular injection of specific antagonists of Ang II type 1 (AT1) or type 2 (AT2) receptors (losartan and PD 123319, respectively), we confirm that activation of brain angiotensin is essential for the expression of adrenalectomy-induced NaCl intake. Moreover, we show that (a) AT1 but not AT2 receptor blockade alone suppresses NaCl intake and (b) doses of AT1 and AT2 receptor antagonists that separately have no effect on NaCl intake, suppress the behavior when combined. It is proposed that AT1 receptors mediate the natriorexigenic effect of Ang II and that AT2 receptors have a permissive role on AT1 receptor stimulation.
Department of Animal Physiology, University of Pennsylvania, Philadelphia 19104, USA. galavern@bisance.citi2.fr
O
O
Galaverna
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Polidori
R R
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Sakai
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F
Liénard
S Y
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Chow
S J
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Fluharty
D000315:Adrenalectomy; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects / Q000502:physiology*; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D019808:Losartan; D008297:Male; D011725:Pyridines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin / Q000502:physiology*; D012965:Sodium Chloride / Q000008:administration & dosage* / Q000494:pharmacology; D013777:Tetrazoles / Q000008:administration & dosage / Q000494:pharmacology*
D057911:Angiotensin Receptor Antagonists; D001713:Biphenyl Compounds; D007093:Imidazoles; D011725:Pyridines; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin; D013777:Tetrazoles; C073402:PD 123319; D012965:Sodium Chloride; D019808:Losartan