Linked Life Data

15240580

Source:http://linkedlifedata.com/resource/pubmed/id/15240580

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2004-7-8
pubmed:abstractText
Thyroid hormones are required for human brain development, but data on local regulation are limited. We describe the ontogenic changes in T(4), T(3), and rT(3) and in the activities of the types I, II, and III iodothyronine deiodinases (D1, D2, and D3) in different brain regions in normal fetuses (13-20 wk postmenstrual age) and premature infants (24-42 wk postmenstrual age). D1 activity was undetectable. The developmental changes in the concentrations of the iodothyronines and D2 and D3 activities showed spatial and temporal specificity but with divergence in the cerebral cortex and cerebellum. T(3) increased in the cortex between 13 and 20 wk to levels higher than adults, unexpected given the low circulating T(3). Considerable D2 activity was found in the cortex, which correlated positively with T(4) (r = 0.65). Cortex D3 activity was very low, as was D3 activity in germinal eminence and choroid plexus. In contrast, cerebellar T(3) was very low and increased only after midgestation. Cerebellum D3 activities were the highest (64 fmol/min.mg) of the regions studied, decreasing after midgestation. Other regions with high D3 activities (midbrain, basal ganglia, brain stem, spinal cord, hippocampus) also had low T(3) until D3 started decreasing after midgestation. D3 was correlated with T(3) (r = -0.682) and rT(3)/T(3) (r = 0.812) and rT(3)/T(4) (r = 0.889). Our data support the hypothesis that T(3) is required by the human cerebral cortex before midgestation, when mother is the only source of T(4). D2 and D3 play important roles in the local bioavailability of T(3). T(3) is produced from T(4) by D2, and D3 protects brain regions from excessive T(3) until differentiation is required.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
89
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3117-28
pubmed:dateRevised
2009-11-3
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Iodothyronine levels in the human developing brain: major regulatory roles of iodothyronine deiodinases in different areas.
pubmed:affiliation
Department of Internal Medicine, Erasmus Medical Center, Dr Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't