Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-6-17
pubmed:abstractText
Areas of adult rat brain that mediate the cardiovascular effects of central angiotensin II (ANG II) predominantly express AT1 ANG II receptors. In contrast, AT2 receptor expression in young rats is transiently increased, reaching a maximum during the first few weeks of life. This study was designed to determine the roles of brain AT1 and AT2 receptors in mediating the central pressor effects of ANG II in young (4-week-old) conscious spontaneously hypertensive rats (SHR). Mean arterial pressure responses to intracerebroventricular (i.c.v.) ANG II (100 ng in 5 microliters) were determined 10 minutes after i.c.v. injection of either the AT1 receptor antagonist Losartan (1.0, 2.5, 5.0, and 10.0 micrograms), the AT2 receptor ligand PD 123319 (3.5 x [10(-6), 10(-4), 10(-2), 10(0)] micrograms), or both. In control rats, i.c.v. Losartan prevented the pressor response to i.c.v. ANG II in a dose-dependent manner (P < 0.05), while i.c.v. PD 123319 alone was without effect. In other animals, pressor responses caused by i.c.v. ANG II-induced vasopressin secretion (VP-component) and sympathetic nervous system activation (SNS-component) were studied individually, with similar result; Losartan prevented the SNS-component, but reduced the VP-component by only 45%, indicating that both pressor components involve AT1 receptor activation. However, doses of Losartan were more effective when combined with 3.5 micrograms of PD 123319 than when given alone (P < 0.05); nearly eliminating the VP-component. These results suggest that i.c.v. ANG-II-induced pressor effects may involve activation of multiple receptor subtypes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0165-3806
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
193-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:8491041-Angiotensin II, pubmed-meshheading:8491041-Angiotensin Receptor Antagonists, pubmed-meshheading:8491041-Animals, pubmed-meshheading:8491041-Antihypertensive Agents, pubmed-meshheading:8491041-Biphenyl Compounds, pubmed-meshheading:8491041-Blood Pressure, pubmed-meshheading:8491041-Brain, pubmed-meshheading:8491041-Disease Models, Animal, pubmed-meshheading:8491041-Heart Rate, pubmed-meshheading:8491041-Hypertension, pubmed-meshheading:8491041-Imidazoles, pubmed-meshheading:8491041-Injections, Intraventricular, pubmed-meshheading:8491041-Losartan, pubmed-meshheading:8491041-Male, pubmed-meshheading:8491041-Pyridines, pubmed-meshheading:8491041-Rats, pubmed-meshheading:8491041-Rats, Inbred SHR, pubmed-meshheading:8491041-Receptors, Angiotensin, pubmed-meshheading:8491041-Sympathetic Nervous System, pubmed-meshheading:8491041-Tetrazoles, pubmed-meshheading:8491041-Vasopressins
pubmed:year
1993
pubmed:articleTitle
Functional roles of brain AT1 and AT2 receptors in the central angiotensin II pressor response in conscious young spontaneously hypertensive rats.
pubmed:affiliation
Department of Pharmacology, University of Texas Health Science Center, San Antonio 78282-7764.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't