Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-2-14
pubmed:abstractText
Although a number of causes of poor fetal growth are known, the involvement of placental transport proteins in the etiology of growth retardation is not understood. The aim of this study was to investigate the activity of the system A amino acid transporter and the Na+/H+ exchanger in vesicles isolated from the microvillous membrane of the syncytiotrophoblast of placentas of appropriate and small for gestational age babies. There were no biochemical differences between the membranes from the two groups of placentas, and there was no difference in the activity of the Na+/H+ exchanger. The initial rate of uptake of methylaminoisobutyric acid (a nonmetabolizable amino acid analogue) was 63% lower in vesicles from placentas of small for gestational age babies. Kinetic analysis of the system A transporter (utilized by methylaminoisobutyric acid) showed that the Vmax in the vesicles from placentas of small for gestational age babies (0.24 +/- 0.03 nmol/mg protein/30 s, n = 5) was significantly lower than that in vesicles from placentas of appropriate for gestational age babies (0.64 +/- 0.09 nmol/mg protein/30 s, n = 4, p < 0.001), whereas the Km was not different between the two groups. It is concluded that there is an abnormality of system A amino acid transporter function in placentas of small for gestational age babies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
661-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Amino acid (system A) transporter activity in microvillous membrane vesicles from the placentas of appropriate and small for gestational age babies.
pubmed:affiliation
Department of Child Health, University of Manchester, St. Mary's Hospital, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't