0000000000358740
AUTHOR
María Cinta García-martínez
Metabolismo lipídico y aterogénesis femenina: acción de hormonas, SERM y fitoestrógenos
Resumen Objetivo Revisar los efectos de la terapia hormonal sustitutiva, en sus distintas formas, en el metabolismo lipidico Fuentes Bibliografia medica hasta septiembre del ano 2000 a traves de MEDLINE Conclusiones Los estrogenos, combinados o no con progestagenos, inducen un perfil lipoproteico favorable. Buena parte de esa accion se ejerce a traves de modificacion en la cinetica de particulas. Las acciones sobre oxidacion de las lipoproteinas de baja densidad (LDL), o el tamano de sus particulas, son motivo de polemica. Nuevos preparados, con capacidad de activar receptores estrogenicos, tambien demuestran ejercer acciones selectivas sobre el metabolismo lipidico
The effect of hormone replacement therapy on Ca2+ mobilization and P-selectin (CD62P) expression in platelets examined under flow cytometry.
A series of events, such as increase of cytoplasmic free calcium (Ca 2+ ) and expression of P-selectin (CD62P), an adhesion molecule, on the platelet surface, are significant indicators of platelet activation. We have used flow cytometry to examine Ca 2+ mobilization and CD62P expression in platelets in whole blood obtained in women prior to, and after, different forms of hormone replacement therapy. Thirty-two women completed a protocol consisting of two consecutive 1-month periods under oestradlol (E 2 ), administered orally (2 mg/day) or transdermally (50 μg/day) in random order, followed by a 4-week transdermal sequential regime, in which, during the last 14 days, either progesterone (3…
Phytoestrogens increase the capacity of serum to stimulate prostacyclin release in human endothelial cells
Both the estrogen receptor (ER) alpha and beta isoforms are expressed in the endothelium. The ER beta has been assigned a crucial role in normal vascular wall function. Prostacyclin has been ascribed a beneficial effect on vessel wall physiology. Isoflavones bind with higher affinity to ER beta. We investigated the hypothesis that their administration to postmenopausal women can promote endothelial prostacyclin production.Twenty-five healthy postmenopausal women with mild climacteric symptoms received capsules containing 55 mg/day isoflavones derived from soy and red clover for 6 months. Cultured human umbilical vein endothelial cells (HUVECs) were exposed for 24 h to serum collected before…
The effect of oral hormone replacement therapy on lipoprotein profile, resistance of LDL to oxidation and LDL particle size
Abstract Objectives: To disclose if oral estradiol (E 2 ), alone or in combination with natural progesterone (P) or medroxyprogesterone acetate (MPA), may modify the oxidizability of low density lipoprotein (LDL), and if the effect is achieved at physiological dosages. LDL oxidizability was assessed by the resistance to oxidation by copper and by the particle size profile, since small particles have increased oxidation susceptibility. Methods: Thirty-three women received two consecutive, two-month length doses of 1 and 2 mg/day of oral E 2 . They were then randomly assigned to a fourteen-day treatment of 2 mg/day E 2 plus either 300 mg/day P or 5 mg/day MPA. A parallel group of experiments …
Impacto del metabolismo lipídico en la aterogénesis femenina
Resumen Objetivo Revisar los mecanismos que, ligados al metabolismo lipidico, determinan riesgo vascular en la mujer posmenopausica Fuentes Bibliografia medica hasta septiembre del ano 2000 a traves de MEDLINE Conclusiones Nuevos datos, ligados a la modificacion de particulas por oxidacion o cambios en su tamano, aclaran considerablemente la influencia de los lipidos en los procesos de aterogenesis
Progestogens stimulate prostacyclin production by human endothelial cells.
BACKGROUND: The effects of progestogens on endothelial physiology are poorly studied. Prostacyclin is a potent vasodilator synthesized by two isoforms of cyclooxygenase (COX) in endothelium. We examined the effects of two clinically used progestogens, progesterone and medroxyprogesterone acetate (MPA), on prostacyclin production by cultured human umbilical vein endothelial cells (HUVEC) and the possible role of progesterone receptors and both COX enzymes. METHODS: Cells were exposed to 1-100 nmol/l of either progesterone or MPA and prostacyclin production was measured in culture medium. RESULTS: Both progestogens significantly increased prostacyclin release in a time- and dose-dependent man…
Estradiol reduces F2α-isoprostane production in cultured human endothelial cells
Free radical-generated F2α-isoprostanes are a group of compounds with vasoconstrictor properties. To investigate whether estradiol exerts antioxidant actions modifying F2α-isoprostane production, cultured human umbilical vein endothelial cells were exposed to estradiol and other compounds and F2α-isoprostanes were measured in culture medium. Exposure to 1 and 10 nM estradiol for 24 h reduced F2α-isoprostane production by 36 and 49%, respectively ( P < 0.001 vs. control). Exposure to antiestrogens alone (ICI-182780 or EM-652) slightly reduced F2α-isoprostanes ( P < 0.05 vs. control), but much less than exposure to estradiol ( P < 0.05). ICI-182780 reversed the estradiol-induced redu…