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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
|
pubmed:dateCreated |
1994-12-12
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pubmed:abstractText |
The umbilical-placental circulation is of vital importance for fetal survival and has a dominant effect on the cardiorespiratory physiology of the fetus. The mechanisms of regulation of umbilical vessels appear to differ from those regulating other vessels. Both clonidine and alpha-methyldopa have been used in the management of hypertensive complications of pregnancy. In contrast to alpha-methyldopa, clonidine does not require previous metabolization but acts directly on the receptors. The action of the two drugs on human umbilical artery was studied in vitro. Forty-eight human umbilical artery segments were dissected and perfused as follows: 9 segments with alpha-methyldopa, 10 with clonidine, 10 with yohimbine, 9 with alpha-methyldopa in combination with yohimbine, and 10 with pure Tyrode's solution. alpha-Methyldopa had a statistically significant vasoconstrictive effect starting at 40 min (p < 0.05) and this effect was blocked by yohimbine (p < 0.05). Clonidine had no vasoconstrictive effect. The present data for clonidine do not confirm the presence of alpha 2-adrenergic receptors in the umbilico-placental circulation which had been indicated by the action of methyldopa.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:issn |
0378-7346
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
38
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
18-20
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading | |
pubmed:year |
1994
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pubmed:articleTitle |
In vitro study of the effect of clonidine on human umbilical artery motility.
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pubmed:affiliation |
Department of Gynecology and Obstetrics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
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pubmed:publicationType |
Journal Article,
Comparative Study,
In Vitro
|