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| Author(s): |
Isabela Rosier Olimpio Pereira
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2004-11-29 |
| Examining board members: |
Dulcineia Saes Parra Abdalla;
José Mendes Aldrighi;
Elfriede Marianne Bacchi;
Marcelo Chiara Bertolami;
Paulo Chanel Deodato de Freitas
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| Advisor: | Dulcineia Saes Parra Abdalla |
| Abstract | |
The interruption of the ovarian production of the estrogen occurred in the menopause increases the risk of cardiovascular disease. Because the replacement of estrogen induces endometrial proliferation and increases the risk of breast cancer and cardiovascular disease, alternatives for the hormonal replacement therapy have been searched. The phytoestrogens are phenolic compounds from plants that possess structural similarity with estrogens. The soy isoflavones genistein, daidzein and glicitein have been notable for their estrogenic, antioxidant and platelet aggregation inhibition effects. The objective of this work was to evaluate the effect of the soy phytoestrogens and the hormonal replacement therapy on vascular reactivity, formation of nitric oxide derivates, lipoprotein oxidation and antibodies anti-heat shock proteins (HSPs) in hypercholesterolemic postmenopausal women. The women were treated with soy germ (I, n=20); 17 beta-estradiol (E, n=17) or 17 beta-estradiol + noretisterone acetate (E+P, n=18) for 3 months after 1 month of placebo. The plasmatic concentrations of NOx (nitrite + nitrate) and S-nitrosothiols were evaluated by chemiluminescence in gaseous phase; nitrotyrosine, antibodies anti-HSPs (HSP60, HSP70 and HSC70), electronegative LDL (LDL-) and estradiol by ELISA; cholesterol oxides (COx) and isoflavones were determined by gas chromatography and high performance liquid chromatography (HPLC), respectively. The analysis of the vascular reactivity was done by high resolution ultrassonography. Data showed a reduction of NOx, LDL-, COx, antibodies anti-HSC70 and an increase of S-nitrosothiols after the treatment in the 3 groups evaluated in relation to the placebo. The concentrations of nitrotyrosine and reactivity anti-HSP70 were reduced only in group I. There was an improvement of the vascular reactivity only in group E, however, it was found a positive correlation between plasmatic concentrations of isoflavones and vascular reactivity in group I. Conclusion: The phytoestrogens of the soy germ and the hormonal replacement therapy have important effects on the bioavailability of nitric oxide (reducing NOx and increasing Snitrosothiols); in the reduction of the oxidation of lipoproteins (COx and LDL-) and on the autoimune response anti-HSC70. Although only the isolated therapy with estradiol improved the vascular reactivity, there was a positive correlation between plasmatic concentrations of isoflavones and vascular reactivity. (AU) | |