Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1997-8-15
pubmed:abstractText
To identify the specific locations of type 2 deiodinase (D2) messenger RNA (mRNA) in the hypothalamus and pituitary gland and determine its regulation by thyroid hormone, we performed in situ hybridization histochemistry, Northern analysis, and quantitative RT-PCR in euthyroid, hypothyroid, and hyperthyroid rats. By in situ hybridization histochemistry, silver grains were concentrated over ependymal cells lining the floor and infralateral walls of the third ventricle extending from the rostral tip of the median eminence (ME) to the infundibular recess, surrounding blood vessels in the arcuate nucleus (ARC), and in the ME adjacent to the portal vessels and overlying the tuberoinfundibular sulci. Silver grains also accumulated over distinct cells in the midportion of the anterior pituitary. In hypothyroid animals, an increase in signal intensity was observed in the caudal hypothalamus, and a marked increase in the number of positive cells occurred in the anterior pituitary. Microdissection of the hypothalamus for Northern and PCR analysis established the authenticity of D2 mRNA in the caudal hypothalamus, and confirmed that the majority of D2 mRNA is concentrated in this region. The distribution of D2 mRNA suggests its expression in specialized ependymal cells, termed tanycytes, originating from the third ventricle. Thus, the tanycyte is the source of the high D2 activity previously found in the ARC-ME region of the hypothalamus. The results indicate that tanycytes may have a previously unrecognized integral role in feedback regulation of TSH secretion by T4.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3359-68
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9231788-Animals, pubmed-meshheading:9231788-Arcuate Nucleus, pubmed-meshheading:9231788-Base Sequence, pubmed-meshheading:9231788-Blotting, Northern, pubmed-meshheading:9231788-Cerebral Cortex, pubmed-meshheading:9231788-DNA Primers, pubmed-meshheading:9231788-Hypothalamus, pubmed-meshheading:9231788-In Situ Hybridization, pubmed-meshheading:9231788-Iodide Peroxidase, pubmed-meshheading:9231788-Male, pubmed-meshheading:9231788-Median Eminence, pubmed-meshheading:9231788-Pituitary Gland, Anterior, pubmed-meshheading:9231788-Polymerase Chain Reaction, pubmed-meshheading:9231788-RNA, Messenger, pubmed-meshheading:9231788-RNA Probes, pubmed-meshheading:9231788-Radioimmunoassay, pubmed-meshheading:9231788-Rats, pubmed-meshheading:9231788-Rats, Sprague-Dawley, pubmed-meshheading:9231788-Thyroid Hormones, pubmed-meshheading:9231788-Thyroxine, pubmed-meshheading:9231788-Triiodothyronine
pubmed:year
1997
pubmed:articleTitle
Regional distribution of type 2 thyroxine deiodinase messenger ribonucleic acid in rat hypothalamus and pituitary and its regulation by thyroid hormone.
pubmed:affiliation
Tupper Research Institute and Department of Medicine, New England Medical Center, Boston, Massachusetts 02111, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.