Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-12-12
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0378-7346
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
In vitro study of the effect of clonidine on human umbilical artery motility.
pubmed:affiliation
Department of Gynecology and Obstetrics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro