Efeito da associação de dieta hiperlipídica e hipoestrogenismo sobre a integridade óssea mandibular de ratas

• Autor(a) principal: Cornélio, Silvio Sandro
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/17310
• topic: Mandíbula; Dieta hiperlipídica; Ovariectomia; Ratas; Rats; Mandible; Fat diet; Ovariectomy; CIENCIAS DA SAUDE

Increased life expectancy of women allows her to live many years after menopause. On the other hand, the western way of life has brought about an increased incidence of obesity and overweight to people. These two situations have attracted the interest of the scientific community, given the deleterious consequences that may occur with the body. The aim of this study was to evaluate the effect of estrogen deficiency associated with high-fat diet on the mandibular bone integrity of rats. Wistar young rats were previously evaluated by vaginal cytology and at 90 days old were divided into 4 groups: control (C4%), Control 19% fat diet (C19%), ovariectomized 4% (OVX4%), ovariectomized and 19% fat diet (OVX 19%). The experimental period started with castration (90 days old) followed by the implementation of high-fat diet for 30 days. At the end of this period, after anesthesia blood was collected for later analysis of serum concentrations of calcium, phosphorus, alkaline phosphatase and estradiol. Mandibular bone, lumbar column L4 and femurs were removed and prepared for physical and biomechanical analysis. There were no differences in food intake, body length or in bone measurements of all groups. Serum calcium decreased significantly in ovariectomized groups. Phosphorus concentrations decreased and alkaline phosphatase increased in all experimental groups, compared to C4%. Among the physical parameters evaluated some differences were showed between the groups. At L4 vertebrae, the immersed and wet weights increased with castration and the high-fat diet, while the percentage of organic material and mineral decreased. In mnadibles, the immersed and wet weights and bone density increased with castration, but decrease with the combination of castration/fat diet. The bone volume and the percentage of water decreased with the intake of fat diet. No changes were observed in the femurs. In the ashes of mandibular bones the percentage of magnesium were significantly increased in all groups. But the calcium and phosphorus did not change. The biomechanical test of the L4 vertebra and femur were not significant differences between the groups. However, in mandibular bone, groups fed with high-fat diet had lower resistance to the applied voltage, compared to normal-fat diet groups. It was evident in these rats that the deficiency of sex steroids associated with high-fat diet negatively influences mandibular bone integrity