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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
7
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pubmed:dateCreated |
1984-4-26
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pubmed:abstractText |
When Sgd 101/75 was compared with clonidine in a number of tests for CNS activity, Sgd 101/75 exhibited little activity in any test. Sgd 101/75 raised BP without affecting HR in several species of anaesthetised animals. The rise in BP was subject to tachyphylaxis, could be antagonised by alpha 1-adrenoceptor antagonists, and was obtainable in reserpinised animals. The vasopressor effect of NA was antagonised by Sgd 101/75. Thus Sgd 101/75 is a directly acting partial agonist for vascular alpha 1-adrenoceptors. On the coaxially stimulated guinea-pig ileum and field stimulated rat vas deferens, the twitch response to single pulse stimulation was reduced by NA or clonidine stimulating prejunctional alpha 2-adrenoceptors. Sgd 101/75 antagonised these inhibitory effects competitively (pA2 for antagonism of clonidine on the vas = 6.12). Sgd 101/75 acted as a specific partial agonist on the alpha 1-adrenoceptors of the guinea-pig taenia caecum that subserve relaxation of this tissue. Sgd 101/75 was a full agonist on the alpha 1-adrenoceptors of the rat anococcygeus in vitro. Phenoxybenzamine (300 pM for 30 min, followed by 20 washes over the next 30 min) reduced contractions of the anococcygeus to Sgd 101/75, but produced little inhibition of NA-induced contractions. In phenoxybenzamine-pretreated preparations, Sgd 101/75 (400 microM) did not antagonise NA (maximal effect and EC50 values not changed significantly), so it was concluded that Sgd 101/75 and NA interact with different alpha 1-adrenoceptor subtypes in this tissue. The subtype specifically activated by Sgd 101/75 was designated the alpha 1s-adrenoceptor. The mouse anococcygeus contained alpha 1s-adrenoceptors, whereas this receptor was absent from the rabbit anococcygeus.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Clonidine,
http://linkedlifedata.com/resource/pubmed/chemical/Norepinephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Phenoxybenzamine,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Adrenergic, alpha,
http://linkedlifedata.com/resource/pubmed/chemical/Sympathomimetics,
http://linkedlifedata.com/resource/pubmed/chemical/indanidine
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0379-0355
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
5
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
425-34
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:6142147-Adrenergic alpha-Agonists,
pubmed-meshheading:6142147-Animals,
pubmed-meshheading:6142147-Clonidine,
pubmed-meshheading:6142147-Electric Stimulation,
pubmed-meshheading:6142147-Hemodynamics,
pubmed-meshheading:6142147-Humans,
pubmed-meshheading:6142147-Muscle, Smooth,
pubmed-meshheading:6142147-Muscle Contraction,
pubmed-meshheading:6142147-Muscle Relaxation,
pubmed-meshheading:6142147-Norepinephrine,
pubmed-meshheading:6142147-Phenoxybenzamine,
pubmed-meshheading:6142147-Receptors, Adrenergic, alpha,
pubmed-meshheading:6142147-Sympathomimetics
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pubmed:year |
1983
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pubmed:articleTitle |
Sgd 101/75: a sympathomimetic that can be used to identify a new subtype of alpha-adrenoceptor, the alpha 1s-adrenoceptor.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Review
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