Dissociation between the circulating renin-angiotensin system and angiotensin II receptors in central losartan-induced hypertension

Autor: A.M. Sugawara, R.C. Vendramini, S.P. Barbosa, I.L. Brunetti, J.V. Menani, L.A. De Luca Jr.
Jazyk: angličtina
Rok vydání: 2002
Předmět:
Zdroj: Brazilian Journal of Medical and Biological Research, Vol 35, Iss 9, Pp 1069-1074 (2002)
Druh dokumentu: article
ISSN: 0100-879X
1414-431X
DOI: 10.1590/S0100-879X2002000900007
Popis: Losartan, an AT1 angiotensin II (ANG II) receptor non-peptide antagonist, induces an increase in mean arterial pressure (MAP) when injected intracerebroventricularly (icv) into rats. The present study investigated possible effector mechanisms of the increase in MAP induced by icv losartan in unanesthetized rats. Male Holtzman rats (280-300 g, N = 6/group) with a cannula implanted into the anterior ventral third ventricle received an icv injection of losartan (90 µg/2 µl) that induced a typical peak pressor response within 5 min. In one group of animals, this response to icv losartan was completely reduced from 18 ± 1 to 4 ± 2 mmHg by intravenous (iv) injection of losartan (2.5-10 mg/kg), and in another group, it was partially reduced from 18 ± 3 to 11 ± 2 mmHg by iv prazosin (0.1-1.0 mg/kg), an alpha1-adrenergic antagonist (P
Databáze: Directory of Open Access Journals