Angiotensin II, via an action at AT1 receptors, may modulate the behavioural effects of ET-1 in conscious rats.
The injection of endothelin-1 (ET-1) (1 pmol/rat) into the dorsolateral periaqueductal gray (PAG) area of freely moving rats induced rotation along the long axis of the body (barrel-rolling). Preinjection (10 min before) of losartan (a selective AT1 receptor antagonist; 50 nmol) to the PAG area reduced the behavioural response to ET-1. In contrast, pretreatment with PD123319 (a selective AT2 receptor antagonist; 50 nmol) did not affect the ET-1-induced barrel-rolling. These results indicate that endogenous angiotensin II, via an action on AT1 receptors, contributes to the barrel-rolling of ET-1 within the brain.
D'Amico
M
M
Institute of Pharmacology and Toxicology, Faculty of Medicine and Surgery, 2nd University of Naples, Italy.
di Filippo
C
C
Berrino
L
L
Rossi
F
F
D000803:Angiotensin I / Q000378:metabolism*; D000804:Angiotensin II / Q000494:pharmacology*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001713:Biphenyl Compounds / Q000494:pharmacology; D004357:Drug Synergism; D019332:Endothelin-1 / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology; D019808:Losartan; D008297:Male; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000378:metabolism; D013777:Tetrazoles / Q000494:pharmacology
D057911:Angiotensin Receptor Antagonists; D001713:Biphenyl Compounds; D019332:Endothelin-1; D007093:Imidazoles; D011725:Pyridines; D011945:Receptors, Angiotensin; D013777:Tetrazoles; D000804:Angiotensin II; C073402:PD 123319; D000803:Angiotensin I; D019808:Losartan