Linked Life Data

3422473

Source:http://linkedlifedata.com/resource/pubmed/id/3422473

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-3-11
pubmed:abstractText
It is generally accepted that the prothoracic glands of insects produce ecdysone, which is converted by a 20-monooxygenase in peripheral tissues to the major molting hormone, 20-hydroxyecdysone. Incubation in vitro of the prothoracic glands of larval or pupal Manduca sexta in the presence of a hemolymph protein fraction (HPF) increased the ecdysteroid content of the medium almost 8-fold. A comparable increase was noted when HPF was added to medium preconditioned with prothoracic glands but from which the glands had been removed. We used a differential RIA to show that a major product of the prothoracic glands in vitro cross-reacts with antiserum (20-hydroxyecdysone-2-succinylthyroglobulin amide; H-2) that retains affinity to ecdysteroids having a modified A ring. However, this product did not bind to antiserum (ecdysone-22-succinylthyroglobulin amide; H-22) that has affinity mainly for ecdysteroids modified at the side chain. We employed radiolabeled precursor studies with prothoracic glands in vitro and a combination of analytical techniques (NMR, CD, MS) to demonstrate that the major ecdysteroid release from the glands is a mixture of 2-dehydroecdysone and 3-dehydroecdysone (1:2), which is rapidly reduced to ecdysone in the presence of HPF. We postulate that the active component of HPF is 3 beta 3 beta (2 beta)-formin-3(2)-ketoecdysteroid reductase. These results may explain several anomalous observations pertaining to the molting of insect fragments in the absence of prothoracic glands and suggest a complex system for the control of insect molting and metamorphosis.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
958-62
pubmed:dateRevised
2010-9-9
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Regulation of the ecdysteroid titer of Manduca sexta: reappraisal of the role of the prothoracic glands.
pubmed:affiliation
Department of Biology, University of North Carolina, Chapel Hill 27599-3280.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.