Avaliação dos efeitos do tratamento com Sildenafil sobre células de medula óssea de camundongos hipercolesterolêmicos

• Ano de defesa: 2015
• Autor(a) principal: Bernardes, Franciane Pereira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Ciências Fisiológicas; Centro de Ciências da Saúde; UFES; Programa de Pós-Graduação em Ciências Fisiológicas
• Palavras-chave em Português: Hypercholesterolemia; ROS; Genotoxic damage; Sildenafil; Hipercolesterolemia; ERO’S; Dano genotóxico; Fisiologia; 612
• Link de acesso: http://repositorio.ufes.br/handle/10/8016

Hypercholesterolemia, besides being a major factor leading to the development of atherosclerosis, causes oxidative and genotoxic damage in bone marrow cells. Sildenafil has been used successfully in cardiovascular research and in the case of atherosclerosis, shows positive effects in the reduction of oxidative stress and the genotoxic damage markers of atherosclerosis in experimental models (Knockout mouse apolipoprotein E - apoE-/- ). In this study we tested the hypothesis that treatment with sildenafil would be able to improve the damage caused by the hypercholesterolemia on the bone marrow cells from apoE-/- mice. Male mice were used at 03 months of age divided into three groups: C57BL/ 6 control (C57), vehicle (apoE-/- V) and treated (apoE-/- S) which were subjected to treatment with Sildenafil 40 mg/kg/Day or vehicle for three weeks. During the treatment period, peripheral blood samples were taken and on the last day of treatment the bone marrow cells from the femurs and tibias were isolated and subjected to flow cytometry protocols, dosage and serum cholesterol micronucleus test. Oxidative stress was evaluated by determining the levels of Reactive Oxygen Species (ROS) superoxide anion (O2 - ) and hydrogen peroxide (H2O2) on cytometry flow assays DHE and DCF, respectively. Information has been obtained on the cell cycle phases of bone marrow cells by staining with propidium iodide (PI) and the estimation of genotoxic and cytotoxic damage was done through the micronucleus test of bone marrow and blood. Statistical analysis was performed using the one-way analysis of variance (ANOVA). When the ANOVA showed significant differences, the Fisher’s test was performed as a post hoc analysis. When appropriate, the Student t test for independent samples was performed. The results are expressed as mean ± SEM and the differences between means were considered statistically significant p < 0.05. Data on ROS indicate that apoE-/- V animals had higher levels of superoxide anion compared with the control group (C57) and the group receiving Sildenafil (apoE-/- V: 2217.6±361.0* versus C57: 1128.2±28.0 versus apoE-/- S: 1125.7±190.8 # ). Hydrogen peroxide levels also had increased in the group apoE-/- V with values about 2847.0±191.0* versus C57: 2181.0±107.7 versus apoE-/- S: 2107.0±80.60# . Regarding the characteristics of the cell cycle, the values obtained indicate a greater DNA fragmentation in the animals of vehicle group compared to the control and treated (apoE-/- V: 2.14±0.12* versus C57: 1.59±0.10 versus apoE-/- S 1.31±0.11# ). It was also observed in the vehicle group had a greater proportion of bone marrow cells when G0/G1 (apoE-/- V: 75.45±0.70* versus C57: 68.60±0.53 versus apoE-/- S: 67.75±1.60# ). Furthermore, the micronucleus data suggest that hypercholesterolemic animals receiving vehicle have significant genotoxic damage in the bone marrow (apoE-/- V: 6.4±0.35* versus C57: 3.5±0.27 versus apoE-/- S: 5.0±0.41# ) and blood (apoE-/- V: 7.6±0.80* versus C57: 4.0±0.37 versus apoE-/- S: 3.95±0.40# ) compared to the group treated with Sildenafil. Together, these results indicate that treatment with sildenafil in hypercholesterolemic mice was able to produce beneficial effects on the bone marrow environment demonstrated by a lower production of ROS, smaller amount of fragmented DNA and least amount of micronucleated cells in the bone marrow and peripheral blood.