Radioresistance of Lymphocytes Incubated at Low Temperatures

Abstract
Suspensions of rat and human lymphocytes were X-irradiated with 10 to 1000 r and incubated at 15[degree] to 42[degree]C for 1 and 7 days. Viable lymphocytes was counted before and after incubation. Incubation at low temperatures inhibited cytotoxic effects of X-rays. Temperatures that protected the lymphocytes against the effects of X-rays were 15[degree], 18[degree], and 22[degree]C for rat lymphocytes and 22[degree] and 27[degree]C for human cells. Incubation at 15[degree] and 18[degree]C was cytotoxic to human but not to rat lymphocytes.