“…Several biological models may be used to evaluate ionizing radiation effect on P-gp activity. However, peripheral blood lymphocytes appear as a promising candidate because present P-gp activity (Chaudary et al, 1992) and have already been widely used to investigate radioinduced changes due to its radiosensitivity and sampling ease (IAEA, 2001;Dainiak, 2002;Amaral, 2005). This study focused on T lymphocytes, which present good quantitative representation (Valensi, 2005), high radiosensitivity (Mori et al, 2005) and exuberant Rh123-efflux by P-gp activity (Drach et al, 1992).…”