Linked Life Data

226338

Source:http://linkedlifedata.com/resource/pubmed/id/226338

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1979-12-18
pubmed:abstractText
In cats, dogs and rats, clonidine (20.0 microgram/Kg, i.v.) reduced the sustained tachycardia evoked by a continuous electrical stimulation of cardiac sympathetic nerve fibres. This effect of clonidine resulting from stimulation of cardiac presynaptic alpha-adrenoceptors could be completely antagonized by phentolamine and prazosin in the dog and the cat, whereas in the rat, prazosin, unlike phentolamine, failed to effectively inhibit the clonidine induced reduction in heart rate. The calculated doses of phentolamine and prazosin needed to produce a 50% antagonism were of similar magnitude in the dog, but in the cat prazosin was about three times less potent than phentolamine. As opposed to clonidine, LD 3098, a potent vascular postsynaptic alpha-adrenoceptor stimulating imidazoline, and phenylephrine (20.0 microgram/Kg, i.v.) did not significantly alter the sympathetic tachycardia in the pithed rat and the spinal dog. These results indicate that compounds stimulating postsynaptic alpha-adrenoceptors may be inactive as agonists of cardiac presynaptic alpha-adrenoceptors within the same animal species. Furthermore, a compound showing selective activity as an antagonist of vascular alpha-adrenoceptors in one species may not necessarily exert the same selective effects in other animals as demonstrated here for prazosin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0148-3927
pubmed:author
pubmed:issnType
Print
pubmed:volume
1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
87-101
pubmed:dateRevised
2009-10-27
pubmed:meshHeading
pubmed:year
1978
pubmed:articleTitle
Effects of prazosin and phentolamine on cardiac presynaptic alpha-adrenoceptors in the cat, dog and rat.
pubmed:publicationType
Journal Article