Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-12-31
pubmed:abstractText
Coho salmon (Oncorhynchus kisutch) thyroid-stimulating hormone (TSH) was isolated by ethanol extraction of pituitary glands from mature coho salmon. Extraction was followed by gel-filtration chromatography on Sephadex G-100 superfine, anion-exchange chromatography on a Whatman DE-52 column, and finally by reverse-phase high-performance liquid chromatography. Fractions were monitored for TSH content by a homologous in vivo bioassay and by immunoblots using anti-human TSH beta-subunit antisera. In vivo treatment of coho salmon parr with coho salmon TSH caused a dose-dependent increase in plasma thyroxine level similar to that induced by bovine TSH. The N-terminal sequence (25 residues) of the salmon TSH beta subunit has 56% sequence identity to that of human TSH beta subunit and is identical to the deduced amino acid sequence of trout TSH beta subunit. The N-terminal sequence (25 residues) of the salmon TSH alpha subunit is identical to gonadotropin alpha-II subunit. Molecular sizes of the alpha and beta subunits are 18,000 and 24,000 daltons, respectively, as estimated by SDS-PAGE. Antiserum generated against salmon TSH, which was preadsorbed with alpha subunit using an alpha-subunit affinity column, detected only salmon TSH beta subunit by immunoblot and specifically stained thyrotropin-producing cells of the pituitary gland. A homologous radioimmunoassay (RIA) was developed using purified salmon TSH standard, iodinated TSH beta subunit, and antiserum generated against salmon TSH. Cross-reactivities of GTH I, GTH II, GTH I beta and GTH II beta subunits, alpha subunit, growth hormone, prolactin, and somatolactin were less than 1%. Displacement curves for serial dilutions of plasma and pituitary extracts of various salmonid species, as well as coho salmon pituitary cell culture medium, were parallel to the coho salmon TSH standards. In contrast, plasma of hypophysectomized juvenile coho salmon and pituitary extracts of Pacific tomcod (Microgadus proximus) did not displace bound radiolabeled salmon TSH. Finally, in vivo injection of juvenile coho salmon with triiodothyronine decreased plasma TSH levels, whereas the goitrogen, methimazole, increased plasma TSH levels. Injection of gonadotropin-releasing hormone agonist did not alter plasma TSH. These data suggest that the RIA is specific for TSH and confirm a negative-feedback relationship between the thyroid hormones and TSH.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0016-6480
pubmed:author
pubmed:copyrightInfo
Copyright 1997 Academic Press.
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
457-71
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9405122-Amino Acid Sequence, pubmed-meshheading:9405122-Animals, pubmed-meshheading:9405122-Antithyroid Agents, pubmed-meshheading:9405122-Cross Reactions, pubmed-meshheading:9405122-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:9405122-Female, pubmed-meshheading:9405122-Gonadotropin-Releasing Hormone, pubmed-meshheading:9405122-Immunohistochemistry, pubmed-meshheading:9405122-Male, pubmed-meshheading:9405122-Methimazole, pubmed-meshheading:9405122-Molecular Sequence Data, pubmed-meshheading:9405122-Oncorhynchus kisutch, pubmed-meshheading:9405122-Oncorhynchus mykiss, pubmed-meshheading:9405122-Pituitary Gland, pubmed-meshheading:9405122-Radioimmunoassay, pubmed-meshheading:9405122-Sensitivity and Specificity, pubmed-meshheading:9405122-Thyrotropin, pubmed-meshheading:9405122-Thyroxine, pubmed-meshheading:9405122-Triiodothyronine
pubmed:year
1997
pubmed:articleTitle
Salmon thyroid-stimulating hormone: isolation, characterization, and development of a radioimmunoassay.
pubmed:affiliation
Northwest Fisheries Science Center, National Marine Fisheries Service, 2725 Montlake Boulevard East, Seattle, Washington 98112, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't