Linked Life Data

1969946

Source:http://linkedlifedata.com/resource/pubmed/id/1969946

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-5-24
pubmed:abstractText
In rat gastric fundus preparations with tone raised by the addition of barium chloride or carbachol, and in the presence of propranolol (2 microM) to prevent beta-adrenoceptor mediated effects, the adrenoceptor agonists noradrenaline, adrenaline, alpha-methylnoradrenaline, isoprenaline, cirazoline and phenylephrine all caused concentration-related relaxant responses. Relaxations to the catecholamines were poorly antagonized by prazosin (0.01-1 microM) resulting in the slopes of Schild plots being less than unity, low pA2 values for prazosin against the catecholamines and a clear relaxant effect of the catecholamines even in the presence of 1 microM prazosin. The prazosin-resistant relaxations were unaffected by higher concentrations of prazosin (2 microM) and propranolol (30 microM) or by further additions of idazoxan (1 microM) or haloperidol (30 microM). The relaxations were not due to a non-specific effect of the catechol nucleus since neither dihydroxyphenylethylene glycol (DOPEG) nor dihydroxyphenylacetic acid (DOPAC) produced relaxant effects at concentrations up to 300 microM. In contrast to the results with the catecholamines, prazosin was a potent antagonist of the relaxant effect of cirazoline and phenylephrine, although the antagonism was difficult to quantify due to a lowering of the slope of the concentration response curves to cirazoline and phenylephrine with the higher concentrations of prazosin (0.1 and 1.0 microM). In conclusion postjunctional relaxatory effects of catecholamines in the rat gastric fundus are mediated partly via alpha 1-adrenoceptors and partly via an atypical adrenoceptor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/3,4-Dihydroxyphenylacetic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Agonists, http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Antagonists, http://linkedlifedata.com/resource/pubmed/chemical/Atropine, http://linkedlifedata.com/resource/pubmed/chemical/Barium, http://linkedlifedata.com/resource/pubmed/chemical/Barium Compounds, http://linkedlifedata.com/resource/pubmed/chemical/Chlorides, http://linkedlifedata.com/resource/pubmed/chemical/Methoxyhydroxyphenylglycol, http://linkedlifedata.com/resource/pubmed/chemical/Prazosin, http://linkedlifedata.com/resource/pubmed/chemical/Propranolol, http://linkedlifedata.com/resource/pubmed/chemical/barium chloride, http://linkedlifedata.com/resource/pubmed/chemical/dihydroxyphenylethylene glycol
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-3573
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Relaxant effects of alpha-adrenoceptor agonists in the rat isolated gastric fundus.
pubmed:affiliation
Dept. of Biological Sciences, Glasgow College, UK.
pubmed:publicationType
Journal Article, In Vitro