Modificações induzidas pela radiação gama em células da medula óssea de camundongos tratados com alfa-tocoferol
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Data
2003
Autores
Moraes, Andrea Aparecida Fátima Souza [UNIFESP]
Orientadores
Ferreira, Alice Teixeira [UNIFESP]
Tipo
Dissertação de mestrado
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O autor so fez o abstract:The bone marrow is a highly radiosensitive organ affected by accidental exposures to ionizing radiation and during radiotherapy. The effects induced by y radiation depend on the tissue absorbed dose and cell repair capacity. Apoptosis is a mode of cell death that results in the deletion of cells in a normal tissue. It also occurs naturally in some neoplasias. The process is induced by radiation and chemotherapic agents. The morphological features are: condensation and fragmentation of the nuclear chromatin and cell fragmentation, producing the apoptotic bodies. The biochemical analysis shows the DNA fragmentation in a ladder pattern. It has been shown that genes are involved in the induction as well as in the inhibition of apoptosis. It has also been shown that calcium is involved in the process of apoptosis depending on cell type. The interest in apoptosis has expanded since its importance in oncology was recognized. Indeed, the early tumor response to radiation and the high radiosensitivity of bone marrow are related to apoptosis. The a-tocopherol (Vitamin E) has been widely used due to its characteristical protection against oxidative stress in various biological systems. Vitamin E is known as a sinergetic antioxidant and it is used to protect the organisms from the effects of physical and chemical agents. Vitamin E restricts the propagation of the chain reaction of reactive oxygen species (ROS), induces a natural protection on biological membranes against radiation injuries that can lead the cells to death by reproductive falency and apoptosis. This work examined the effects of gamma radiation in the bone marrow cells using the a-tocopherol as a radioprotector. Mice (C57BU10) were subdivided into 4 groups: GC (Control), GI (Irradiated), GC-11 (Control+VitE), and GI-11 (irradiated+VitE). GC-11 and GI-11 were treated intraperitoneally with VitE (40mg/Kg)/14days. The animals of GI and GI-11 were submitted to gamma irradiation in a telecobalt therapy source (Alcyon RI), with rate of 0,61 cGy/min. The mice were whole body irradiated with the dose of 7Gy. A flow cytometric morphological analysis were performeda(au)
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São Paulo: [s.n.], 2003. 73 p.