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1.
Mol Cell Endocrinol ; 339(1-2): 136-43, 2011 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21536098

RESUMO

In this work we provide evidence that estrone "per se" modulates cellular endothelial growth and survival, events that play key roles in the development of vascular disease. Moreover, under oxidative stress conditions the hormone prevented apoptosis triggered by hydrogen peroxide. Although estrone did not affect E-selectin and VCAM-1 mRNAs synthesis, the hormone prevented the expression of these adhesion molecules induced by the proinflammatory agent LPS. The steroid partially attenuated leukocyte adhesion not only under basal conditions but also in the presence of LPS. Using ICI182780 compound as estrogen receptor antagonist, and PD98059 as MAPK inhibitor we obtained evidence that the mitogenic action of estrone involved the participation of ER and MAPK transduction pathway activation. The presence of estradiol impaired the effect of estrone on cell proliferation and vasoactive production. These results suggest that estrone exhibits a remarkable biological action on endothelial cells, modulating vasoactive production, proliferation, apoptosis, and cell adhesion events.


Assuntos
Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Estrona/farmacologia , 17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Animais , Aorta/citologia , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Fragmentação do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Selectina E/metabolismo , Células Endoteliais/fisiologia , Endotélio Vascular/fisiologia , Equilina/farmacologia , Estradiol/farmacologia , Feminino , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/fisiologia , Óxido Nítrico/metabolismo , Ratos , Ratos Wistar , Timidina/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
2.
J Chromatogr Sci ; 39(9): 385-7, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11565948

RESUMO

Equine unsaturated estrogens are the main components of brand formulations indicated for hormonal replacement therapy in both hypogonadic and postmenopausal women. These hormones are produced by the fetoplacental unit during equine gestation. A method is described for the quantitative determination of equilenin (EL), equilin (EQ), 17alpha-dihydroequilin (17dEQ), and estrone (El) in the plasma of a pregnant mare. Blood samples are obtained weekly during pregnancy by jugular venipuncture using sodium ethylenediaminetetracetic as the anticoagulant. For the quantitation of these estrogens, plasma is submitted to enzymatic hydrolysis followed by liquid-liquid extraction. A high-performance liquid chromatographic system equipped with a UV detector set at 220 nm and an ODS Hypersil column is used. The method met precision, specificity, and accuracy requirements. The hormonal levels determined in one target mare throughout pregnancy were 97.91 to 449.13, 116.47 to 266.02, 74.92 to 235.54, and 84.26 to 300.03 ng/mL, reaching a maximum towards the 25th, 20th, 33rd, and 27th weeks, respectively, for E1, EL, EQ, and 17dEQ. The method was successfully tested by quantitating these estrogens in the plasma from a pregnant mare. Its applicability to the study of estrogen bioavailability and bioequivalence is suggested.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Equilina/análogos & derivados , Estrogênios/sangue , Cavalos/sangue , Animais , Ácido Edético , Equilenina/sangue , Equilina/sangue , Estrona/sangue , Feminino , Hidrólise , Gravidez , Sensibilidade e Especificidade
3.
Climacteric ; 1(4): 284-9, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11907935

RESUMO

OBJECTIVES: To determine the relative bioavailability of the estrogenic components of a generic brand of conjugated estrogens marketed in Chile in comparison to that of Conpremin (Premarin in the United States). METHODS: A randomized cross-over study was conducted on 16 healthy postmenopausal women receiving single oral doses of either two Conpremin 0.625-mg tablets or two 0.625-mg tablets of the generic brand, with a 14-day wash-out interval between doses. A gas chromatography tandem mass spectrometry assay was used to determine estrogen components. RESULTS: The peak plasma concentrations of unconjugated and total estrone and equilin, unconjugated 17 beta-dihydroequilin and 17 beta-estradiol were higher and occurred earlier with the generic conjugated estrogens than with Conpremin. The 90% confidence limits for both variables lay outside the accepted bioequivalence limits of 80-125%. Additionally, no measurable plasma concentration of unconjugated delta 8,9-dehydroestrone or 17 beta-delta 8,9-dehydroestradiol was seen after administration of the generic conjugated estrogens. CONCLUSIONS: These pharmacokinetic results indicate that the generic tablets do not have the modified-release characteristics of Conpremin tablets. In addition, the absence of delta 8,9-dehydroestrone and 17 beta-delta 8,9-dehydroestradiol in the plasma indicates that the generic form is not compositionally equivalent to Conpremin.


Assuntos
Medicamentos Genéricos/farmacocinética , Equilina/análogos & derivados , Estrogênios Conjugados (USP)/farmacocinética , Adulto , Disponibilidade Biológica , Chile , Estudos Cross-Over , Equilina/sangue , Equilina/farmacocinética , Estradiol/sangue , Estradiol/farmacocinética , Estrona/sangue , Estrona/farmacocinética , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa , Equivalência Terapêutica , Estados Unidos
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