Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-6-24
pubmed:abstractText
Our study had three purposes: 1) to determine whether 5-methyl-urapidil, topically applied to the ventrolateral medulla, produces hypotension by activating serotonin-1A (5-HT1A) receptors, 2) to determine whether 5-methyl-urapidil given i.v. produces hypotension in part by activating 5-HT1A receptors in the ventrolateral medulla, and 3) to determine the specific site within the ventrolateral medulla where 5-methyl-urapidil elicits a hypotensive response. In terms of the first purpose, 5-methyl-urapidil applied bilaterally to the intermediate area of the ventral surface of the medulla (1.2 micrograms/side) of chloralose-anesthetized cats produced a decrease in mean arterial pressure of -39 +/- 4 mm Hg (N = 8). Prior blockade of 5-HT1A receptors at this site with bilateral application of spiperone (30 micrograms/side) prevented the hypotensive effect of 5-methyl-urapidil (mean blood pressure now increased by 5 +/- 4 mm Hg). Pretreatment with the alpha-1 adrenoceptor antagonist, prazosin, did not prevent the hypotensive effect of 5-methyl-urapidil. In terms of the second purpose, spiperone applied bilaterally to the ventral surface of the medulla counteracted a significant portion of the hypotensive effect of 5-methyl-urapidil given by the i.v. route. The dose of 5-methyl-urapidil given intravenously was below the dose that produces alpha-1 adrenoceptor blockade. In terms of the third purpose, microinjection of 5-methyl-urapidil into central nervous system sites associated with the intermediate area was found to have its greatest hypotensive effect at the subretrofacial nucleus. Mean arterial pressure decreased by 74 +/- 14 mm Hg (N = 3) after bilateral microinjection of 25 ng of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
257
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
861-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
The role of serotonin-1A receptor activation and alpha-1 adrenoceptor blockade in the hypotensive effect of 5-methyl-urapidil.
pubmed:affiliation
Department of Pharmacology, Georgetown University School of Medicine, Washington, D.C.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't