Linked Life Data

8418920

Source:http://linkedlifedata.com/resource/pubmed/id/8418920

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-2-8
pubmed:abstractText
The overall objectives of this study were to determine whether the rapid decrease in estrogen receptor (ER) binding in the rat uterus after an injection of estradiol and subsequent recovery of ER levels was accompanied by similar changes in ER mRNA levels. Furthermore, the effect of progesterone administered under conditions known to decrease ER binding, in the rat uterus, on ER mRNA levels was also investigated. Ovariectomy for 14 days brought about a 3-fold increase in rat uterine ER mRNA levels, and these elevated levels were decreased by a 3-day treatment with 2 micrograms of estradiol in ethanol/saline injected i.p. In the ovariectomized rat, 1 and 5 micrograms of estradiol brought about small but significant decreases in ER mRNA levels in 1 h, which did not parallel the rapid decrease in ER binding at that time reported earlier. The 10-micrograms dose of estradiol brought about a bigger decrease in ER mRNA levels. In the ovariectomized rat primed with estradiol (2 micrograms/day in ethanol/saline), the administration of 2 micrograms of estradiol brought about no change in uterine ER mRNA levels at 6 h as compared to the 1-h time point if the values were not corrected for beta-actin, which was significantly increased at 6 h. A dramatic increase in ER mRNA levels 12 h after the estradiol injection preceded the increase in ER binding observed at 18 h. Progesterone (0.8 mg/kg body weight [BW]) in the absence of estrogen priming brought about minimal but significant inhibition of ER mRNA levels 12 and 18 h after administration, with no effects at 1 and 6 h. In the presence of estrogen priming, the 0.8-mg/kg BW dose of progesterone did not cause any changes in ER mRNA levels beyond those brought about by estrogen alone after 1 h, even though it has been shown to significantly decrease ER binding. This was also true when a larger dose of progesterone (2.0 mg/kg BW) was used, a dose that decreases ER binding to a significantly greater extent than the 0.8-mg/kg BW dose. However, the 4.0-mg/kg BW dose of progesterone decreased ER mRNA levels. Thus a single injection of estradiol appears to cause a decrease in ER binding primarily by accelerated receptor processing and degradation with small changes in ER mRNA within the first hour. A significant increase in uterine ER mRNA at 12 h precedes increased ER binding at 18 h. This indicates new synthesis of ER during the recovery period.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-98
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Changes in rat uterine estrogen receptor messenger ribonucleic acid levels during estrogen- and progesterone-induced estrogen receptor depletion and subsequent replenishment.
pubmed:affiliation
Department of Physiology and Endocrinology, Medical College of Georgia, Augusta 30912-3000.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.