Jornal de Toxicologia Clínica
Acesso livre
ISSN: 2161-0495
ISSN: 2161-0495
Pouliliou Stamatia, Papaiakovou Marina, Kareli Dimitra, Lialiaris Theodore and Koukourakis I Michael
X-rays are widely used in the treatment of cancer. Nevertheless, radiation may induce damage to normal tissues, through free radical release and Deoxyribonucleic acid (DNA) damage. Amifostine is a broad spectrum cytoprotective agent with free radical scavenger and DNA repair activity that reduces toxicity during radiotherapy and chemotherapy. The aim of the present in vivo study was to investigate the cytoprotective efficacy of amifostine against chromosomal damage induced on peripheral blood lymphocytes in cancer patients under radiotherapy for pelvic tumors. The levels of genotoxicity, cytostaticity and cytotoxicity were quantitatively evaluated using the Sister Chromatid Exchange (SCE) methodology, the Proliferation Rate Index (PRI), the Mitotic Index (MI). PBMCs were collected at 0, 5 and 19 days from patients with pelvic tumors undergoing daily fractionated radiotherapy. Five patients received Radiotherapy (RT) alone (Group A) and 5 received RT supported with amifostine (1000 mg sc.) (Group B) before each RT fraction. A gradual increase of SCEs was noted in group A (p=0.03) and a rather stable score in group B by increasing the days of radiotherapy. At day 19 a significant increased SCE number characterized group A (p=0.005). The mitotic index was significantly reduced by increasing the days of radiotherapy in both groups A and B (p=0.02 and 0.01 respectively) and there was no difference between groups at the various time points. The proliferation rate index was not affected. Pelvic radiation induces a significant amount of SCEs in PBMCs and reduces the mitotic index, implying a potential leukemogenic and certainly cytotoxic activity. Amifostine daily administration although did not protect against cytotoxic damage it reduced the amount of SCEs suggestive of a protection against the stochastic effects of radiation.