Linked Life Data

6401244

Source:http://linkedlifedata.com/resource/pubmed/id/6401244

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1983-2-25
pubmed:abstractText
The abilities of various agonistic and antagonistic analogs of GnRH to modulate ovarian estrogen production were compared with their relative potencies to regulate pituitary LH release. Granulosa cells from immature hypophysectomized rats were cultured for 2 days in the presence of FSH and aromatase substrate (delta 4-androstenedione), with or without various concentrations of GnRH agonists or 10(-8) M GnRH plus various concentrations of selected GnRH antagonists. FSH treatment increased estrogen production, whereas concomitant treatment with various GnRH agonists resulted in dose-dependent decreases in estrogen production. des-Gly10-[D-Ser(TBu)6] Pro9-NHEt-GnRH proved most potent at both the ovarian and pituitary levels, being 170- and 190-fold greater than those values for the GnRH decapeptide, respectively. In general, the ovarian and pituitary potencies of all 10 agonists studied were comparable, with a correlation coefficient of 0.98. When added together with 10(-8) M GnRH, the GnRH antagonists caused dose-dependent blockage of the inhibitory effect of GnRH. Among 7 antagonists tested, [Ac-D-Phe1,D-p-cl-Phe2,D-TYrp3,6]GnRH was shown to be most potent at the pituitary level (half maximal inhibitory dose ratio: IDR50 antagonist/GnRH = 0.17) and blocked the GnRH inhibition at the ovarian level with an IDR50 value of 4.4. The potencies of the antagonists to block the GnRH effect at the pituitary and ovarian levels were comparable, yielding a correlation coefficient of 0.97. Although one cannot rule out subtle differences in the specificities of the respective GnRH target tissues due to minor disparities between pituitary and ovarian potencies of some analogs, the present results demonstrate an overall agreement of responsiveness between ovarian granulosa cells and pituitary gonadotrophs to GnRH agonists and antagonists.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
112
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
689-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Relative potencies of gonadotropin-releasing hormone agonists and antagonists on ovarian and pituitary functions.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.