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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5
|
| pubmed:dateCreated |
1984-2-14
|
| pubmed:abstractText |
This study demonstrates that in spite of measured normal concentrations of carrier proteins one cannot deduce in all cases a normal fT3 from a normal level of TT3 when l-thyroxine given for diagnostic or therapeutic purposes is present in excess. The displacement of l-triiodothyronine from its binding sites is shown in 35 patients with non-toxic goitre who received an oral dose of 200 micrograms l-thyroxine/die for two weeks. Apart from a significant increase of TT4 (from 7.85 to 14.21 micrograms/dl equal + 81%) and of fT4 (from 1.58 to 3.7 ng/dl equal + 134%) there is only a slight increase in TT3 from 148 to 158 ng/dl (equal + 10%) after 14 days of treatment. By contrast fT3 rises clearly from 4.97 to 8.07 pg/ml equal + 63% (normal range: 2.8-5.6 pg/ml). Compared with the increase of TT3 (+ 10%) the free T3 rises by a factor of 6.3 (63%/10%). On account of higher affinity of l-thyroxine to binding proteins the free T4 is influenced to a lesser degree. Compared with the increase of TT4 (+ 81%) free T4 rises by a factor of 1.6 (134%/81%). It is supposed that the serum concentration of free T3 can be increased despite a normal concentration of TT3 when l-thyroxine is present in excess. Therefore, for laboratory work fT3 should be assigned a higher validity than TT3 when patients are treated with comparatively high doses of l-thyroxine.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0029-5566
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
22
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
251-4
|
| pubmed:dateRevised |
2007-1-12
|
| pubmed:meshHeading | |
| pubmed:year |
1983
|
| pubmed:articleTitle |
Increased serum concentration of free L-triiodothyronine in patients treated with L-thyroxine.
|
| pubmed:publicationType |
Journal Article
|