Linked Life Data

7882898

Source:http://linkedlifedata.com/resource/pubmed/id/7882898

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-4-12
pubmed:abstractText
We have examined the effect of two LHRH antagonists (Nal-Glu and Nal-Arg antagonists) on the basal progesterone (P4), pregnenolone (P5) and 20 alpha-dihydroprogesterone (20 alpha-DHP) production by luteal cells obtained from day 8 pregnant rats. A dose of 0.1 mmol/l of Nal-Glu or Nal-Arg attenuated basal P4 production by luteal cells after 12, 24 or 48 h of incubation. P5, a precursor for P4 synthesis was also reduced by both doses of Nal-Glu or Nal-Arg (0.1 mmol or 0.1 mumol/l) after 24 h of incubation. A period of 12 h was not sufficient to inhibit P5 production by luteal cells incubated with both doses of Nal-Glu or with the lower dose of Nal-Arg. The higher dose of Nal-Glu and Nal-Arg remained effective in attenuating P5 production by luteal cells after 48 h of incubation. We measured the production of a metabolite of P4, i.e., 20 alpha-DHP to assess whether this suppression in P4 production is due to an enhancement in the P4 metabolism by increasing the activity of 20 alpha-hydroxydehydrogenase. However, instead, we observed (i) a decrease in the production of 20 alpha-DHP by the higher dose of Nal-Glu and Nal-Arg after 12, 24 or 48 h of incubation and (ii) a decrease or no change in the production of 20 alpha-DHP by the lower dose of Nal-Glu or Nal-Arg at all time periods of incubation. Based on these observations we conclude that LHRH antagonists exert a direct effect on the corpus luteum and suppress luteal steroidogenesis. This suppression in luteal steroidogenesis could be due to a decrease in the activity of any one of these enzymes of the steroidogenic pathway, viz., cholesterol side chain cleavage (P450scc), a rate limiting enzyme involved in the synthesis of P5 from cholesterol, or 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), which catalyzes the oxidation of P5 to P4 or due to a decrease in activity of both enzymes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0743-5800
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
365-76
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Inhibition of luteal steroidogenesis by two LHRH antagonists (Nal-Glu and Nal-Arg antagonists) in the pregnant rat.
pubmed:affiliation
Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310-1495.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't