Effect of a non-peptide angiotensin receptor antagonist on water intake caused by centrally administered carbachol in the rat.
Angiotensin II (ANG II) administered centrally produces drinking by acting on subtype 1 ANG II (AT1) receptors. Carbachol, a cholinergic receptor agonist, also induces drinking behavior by a central action. In the present study we determined whether the response to carbachol also involves AT1 receptors. Male Holtzman rats (250-300 g) with stainless steel cannula implanted into the lateral ventricle (LV) were used. Water intake after injection of 0.15 M NaCl (1.0 microliter) into the LV was 0.2 +/- 0.01 ml/h (N = 8). The AT1 receptor antagonist DUP-753 (50 nmol/microliters) injected into the LV reduced water intake induced by ANG II (10 nmol/microliters) from 9.2 +/- 1.4 to 0.4 +/- 0.1 ml/h (N = 8), and water intake induced by carbachol (2 nmol/microliters) from 9.8 +/- 1.4 ml/h to 3.7 +/- 0.8 ml/h (N = 8). These results suggest that AT1 receptors play a role in the drinking behavior observed after central cholinergic stimulation in rats.
Reis
L C
LC
Departamento de Ciências Fisiológicas, Universidade Estadual Paulista, Araraquara, Brasil.
Saad
W A
WA
Camargo
L A
LA
Renzi
A
A
Menani
J V
JV
D000804:Angiotensin II / Q000008:administration & dosage*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001713:Biphenyl Compounds / Q000494:pharmacology*; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology*; D004326:Drinking / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D019808:Losartan; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000502:physiology; D013777:Tetrazoles / Q000494:pharmacology*
D057911:Angiotensin Receptor Antagonists; D001713:Biphenyl Compounds; D007093:Imidazoles; D011945:Receptors, Angiotensin; D013777:Tetrazoles; D000804:Angiotensin II; D002217:Carbachol; D019808:Losartan