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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-1-30
pubmed:abstractText
Iodine incorporation into thyroglobulin is dependent on the activities of both thyroperoxidase (TPO) and thyroid dual oxidase 2 (DuOx2). Although TPO expression is decreased in some thyroid nodular lesions, DuOx1 and 2 mRNA expressions are maintained, but DuOx H2O2-generating activity has never been evaluated in such tumors. Our goal was to determine DuOx activity in hypofunctioning lesions of the thyroid. We evaluated H2O2 generation by DuOx in 12 paranodular to cold nodule samples, 17 non-toxic multinodular goiters (MNG; 33 samples), 3 papillary carcinomas (PC; 4 samples), 3 follicular carcinomas (FC; 4 samples), and 10 follicular adenomas. DuOx activity was detected in all paranodular tissues (121+/-23 nmol H2O2/h per mg protein), but was undetectable (<1 nmol H2O2 generated) in all PC, two out of four FC samples and seven out of ten adenomas. In 11 MNG at least two different areas of the goiter have been evaluated, and in 5 of these goiters one of the samples had DuOx activity below the limit of detection. The coefficient of variation in MNG samples ranged from 11.3 to 57.2%. Interestingly, in all the adenomas studied, TPO activity (486+/-142 U/g protein, n=8) was well within the range found in paranodular tissues (414+/-116 U/g protein, n=3). We found a significant negative correlation between DuOx and TPO activities, suggesting that these enzymes are regulated in opposite directions, at least in thyroid tumors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1479-683X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
158
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
223-7
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Negative correlation between thyroperoxidase and dual oxidase H2O2-generating activities in thyroid nodular lesions.
pubmed:affiliation
Laboratório de Fisiologia Endócrina Doris Rosenthal from Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21949-900, Brasil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't