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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1986-11-18
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pubmed:abstractText |
The effects of indoramin on sympathetic neuroeffector transmission in rabbit isolated blood vessels were examined. Indoramin reduced the contractions of pulmonary artery evoked by electrical-field stimulation. The IC50 was 7.4 X 10(-8) M. In the presence of cocaine + corticosterone + propranolol, the IC50 was 5 X 10(-7) M. Amphetamine did not antagonize the steady-state inhibition caused by indoramin. Indoramin caused a slight enhancement of the field-stimulation-evoked 3H-overflow from pulmonary artery preloaded with 3H-noradrenaline. In the presence of cocaine + corticosterone + propranolol, indoramin also enhanced the stimulation-evoked 3H-overflow slightly. The effect of indoramin on stimulation-evoked 3H-overflow depended only slightly on stimulation frequencies (1-30 Hz): small enhancement at 1 Hz and nonsignificant changes at 3-30 Hz. Pretreatment with indoramin did not attenuate the inhibitory effect of clonidine on the stimulation-evoked 3H-overflow seen with bretylium. Indoramin and desmethylimipramine reduced the 3H-accumulation by aorta preloaded with 3H-noradrenaline. The IC50 was 3 X 10(-5)M (indoramin) and 10(-8)M (desmethylimipramine). Indoramin inhibited the contractions of aorta evoked by noradrenaline, phenylephrine, histamine and serotonin in a competitive manner. The corresponding pA2 values were 7.54, 7.98, 7.45, and 6.61. Indoramin decreased the maximal contractions of rabbit aorta evoked by potassium. These results suggest that indoramin is a potent competitive antagonist of postsynaptic alpha 1-adrenoceptors, while it may only have a slight inhibitory effect on presynaptic alpha 2-adrenoceptors. Indoramin is devoid of bretylium-like adrenergic neurone blocking activity, while it may act as reserpine. It is a weak inhibitor of the uptake-1 mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:issn |
0160-2446
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
8
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1020-7
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:2429075-Adrenergic Fibers,
pubmed-meshheading:2429075-Animals,
pubmed-meshheading:2429075-Aorta,
pubmed-meshheading:2429075-Indoles,
pubmed-meshheading:2429075-Indoramin,
pubmed-meshheading:2429075-Neuroeffector Junction,
pubmed-meshheading:2429075-Pulmonary Artery,
pubmed-meshheading:2429075-Rabbits,
pubmed-meshheading:2429075-Receptors, Adrenergic, alpha,
pubmed-meshheading:2429075-Synaptic Transmission
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pubmed:articleTitle |
Pre- and postsynaptic effects of indoramin on sympathetic neuroeffector transmission in rabbit aorta and pulmonary artery.
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pubmed:publicationType |
Journal Article
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