Linked Life Data

2566501

Source:http://linkedlifedata.com/resource/pubmed/id/2566501

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1989-7-12
pubmed:abstractText
Tyrosine is the precursor of catecholamines. Small doses of tyrosine produce tachycardia and hypertension while higher doses produce bradycardia and hypotension in anaesthetised rats. The mechanism of these effects has not been established. An increased synthesis and release of catecholamines has been suggested to be the mechanism. Various pretreatments were given to anaesthetised Wistar rats to study the influence of a blockade of L-tyrosine metabolism and thus a blockade of catecholamine synthesis, on these cardiovascular effects: valine, which inhibits tyrosine uptake into brain, alpha-methyl-p-tyrosine, which blocks the rate-limiting enzyme, tyrosine hydroxylase, carbidopa and benserazide, which both inhibit dopa decarboxylase, and desipramine, which blocks catecholamine re-uptake. Benserazide and alpha-methyl-p-tyrosine partially blocked the stimulatory effects of tyrosine. None of the pretreatments were able to block effectively the inhibitory effects of L-tyrosine. Therefore, the metabolism of tyrosine to form catecholamines may be involved in the stimulatory but not in the inhibitory cardiovascular effects of L-tyrosine. Valine pretreatment did not antagonize the depressant effects of tyrosine. Since valine blocks the uptake of L-tyrosine into the brain, the depressant effects of L-tyrosine might be peripheral rather than central in origin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
163
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
209-17
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Cardiovascular effects of L-tyrosine: influence of blockade of tyrosine metabolism.
pubmed:affiliation
Department of Pharmacology and Toxicology, University of Helsinki, Finland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't