Uptake and interconversion of the Z and E isomers of 17 alpha-iodovinyl-11 beta-methoxyestradiol in the immature female rat.
Steroids
; 62(2): 244-52, 1997 Feb.
Article
em En
| MEDLINE
| ID: mdl-9055384
ABSTRACT
This study compares the specific uptake and retention of the Z and E isomers of 17 alpha-iodovinyl-11 beta-methoxyestradiol (IVME2) in estrogen target tissues in immature female rats following intraperitoneal injection. Estrogen receptor binding studies in vitro showed that the Z-IVME2 had greater affinity than the E-IVME2, but our initial in vivo data, comparing 125I-labeled E- or Z-IVME2 in separate studies showed no difference between the two isomers in either uptake or retention. These results were confirmed when the two isomers, labeled either with 123I or 125I, were injected simultaneously, allowing direct comparison of uptake and retention patterns in the same animal. Analysis of the nature of the radioiodinated estrogens in estrogen target tissues showed that at all time points, the estrogen target tissues contained mainly the E isomer, even at short times after injection of Z isomer. Although the Z-IVME2 was reasonably stable in the injectant, analysis of a peritoneal lavage soon after intraperitoneal injection of Z-[125I]-IVME2 showed that mainly the E isomer was present, suggesting that the conversion occurred prior to uptake by the tissues. In vitro studies with intraperitoneal fluid and serum showed that denaturing by heating at 65 degrees C substantially reduced their ability to affect the conversion of Z to E isomer, suggesting a possible enzymatic conversion.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estradiol
Limite:
Animals
Idioma:
En
Revista:
Steroids
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos