Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2005-10-11
pubmed:abstractText
It has been shown that the pressor responses to microinjection of L-glutamate in the rostral ventrolateral medulla (RVLM) are augmented in spontaneously hypertensive rats (SHR), and that these augmented responses are not altered by chronic conventional antihypertensive treatment. The aim of the present study was to determine the effect of chronic oral treatment with a new angiotensin II type 1 (AT(1)) receptor antagonist, RNH-6270 (the active form of olmesartan medoxomil), on cardiovascular responses to excitatory amino acids in the RVLM of SHR. SHR (12 weeks old) were treated with RNH-6270 (30 mg/kg/day) or vehicle for 4 weeks. At 16 weeks of age, L-glutamate (2 nmol), N-methyl-D-aspartate (NMDA; an ionotropic glutamate receptor agonist (20 pmol)), or (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD; a metabotropic glutamate receptor agonist (1 nmol)) was microinjected into the RVLM of rats. The pressor responses to microinjection of L-glutamate or NMDA in the RNH-6270-treated SHR (+28.3 +/- 1.0 and +48.3 +/- 2.5 mm Hg, respectively) were significantly smaller than those in untreated SHR (+45.7 +/- 2.2 and +69.4 +/- 7.0 mm Hg, respectively, P < 0.05 each); however, they were still greater than those in the Wistar-Kyoto rats (+21.7 +/- 1.0 and +28.6 +/- 3.3 mm Hg, respectively, P < 0.05 each). In contrast, the augmented pressor responses to microinjection of (1S,3R)-ACPD in SHR were not affected by the RNH-6270 treatment. These results demonstrated that chronic oral treatment with RNH-6270, an AT(1) receptor antagonist, partly normalizes the pressor responses to L-glutamate or NMDA, but not (1S,3R)-ACPD, in the RVLM of SHR, suggesting that endogenous angiotensin II may be involved in the exaggerated pressor response to l-glutamate, probably through its ionotropic glutamate receptors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1872-6240
pubmed:author
pubmed:issnType
Electronic
pubmed:day
5
pubmed:volume
1058
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
161-6
pubmed:meshHeading
pubmed-meshheading:16143317-Angiotensin II Type 1 Receptor Blockers, pubmed-meshheading:16143317-Animals, pubmed-meshheading:16143317-Autonomic Pathways, pubmed-meshheading:16143317-Blood Pressure, pubmed-meshheading:16143317-Drug Administration Schedule, pubmed-meshheading:16143317-Drug Interactions, pubmed-meshheading:16143317-Excitatory Amino Acid Agonists, pubmed-meshheading:16143317-Glutamic Acid, pubmed-meshheading:16143317-Hypertension, pubmed-meshheading:16143317-Imidazoles, pubmed-meshheading:16143317-Male, pubmed-meshheading:16143317-Medulla Oblongata, pubmed-meshheading:16143317-Rats, pubmed-meshheading:16143317-Rats, Inbred SHR, pubmed-meshheading:16143317-Rats, Inbred WKY, pubmed-meshheading:16143317-Receptors, N-Methyl-D-Aspartate, pubmed-meshheading:16143317-Reticular Formation, pubmed-meshheading:16143317-Sympathetic Nervous System, pubmed-meshheading:16143317-Synaptic Transmission, pubmed-meshheading:16143317-Tetrazoles, pubmed-meshheading:16143317-Treatment Outcome, pubmed-meshheading:16143317-Vasoconstriction
pubmed:year
2005
pubmed:articleTitle
Chronic administration of olmesartan attenuates the exaggerated pressor response to glutamate in the rostral ventrolateral medulla of SHR.
pubmed:affiliation
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
pubmed:publicationType
Journal Article