RESUMO
Estrogen deficiency is associated with aging and increases the incidence of metabolic syndrome and hypertension. In this study, the effects of tibolone, a synthetic steroid, on the cardiovascular system, liver lipid metabolism, and redox status were evaluated, in ovariectomized (OVX) rats with renovascular hypertension (two-kidneys, one-clip, OVX + 2K1C). This study encompassed direct measurements of mean arterial pressure , plasma biochemical analysis, liver lipid contents, and assessments of the mitochondrial and peroxisomal ß-oxidation capacities. Additionally, the liver redox status was assayed. Tibolone significantly reduced the mean arterial pressure of OVX + 2K1C rats, albeit reducing total and high-density lipoprotein (HDL) cholesterol levels. In the liver, although exerting an undesirable inhibition of mitochondrial and peroxisomal ß-oxidation, tibolone reversed steatosis. Tibolone also improved the liver redox status: the reduced glutathione contents and the activity of glucose-6-phosphate dehydrogenase were restored by this compound, which also reduced the levels of thiobarbituric acid-reactive substances and the generation of mitochondrial reactive oxygen species. So, tibolone reversed the main alterations caused by hypertension and estrogen deficiency.
