Sister-chromatid exchange induction by sodium selenite: Dependence on the presence of red blood cells or red blood cell lysate

Abstract

Sodium selenite (Na 2SeO 3) sister-chromatid exchange (SCE) induction was studied in both short-term and long-term cell cultures. The ability of Na 2SeO 3 to induce SCEs was found to depend on the culture conditions employed. Concentrations of Na 2SeO 3 (7.90 × 10 −6 M and greater) that produced elevated SCE frequencies in whole blood cultures resulted in control level SCE frequencies (6–8 SCEs/cell) in Ficoll-Hypaque-purified lymphocyte cultures. However, whole blood and purified lymphocyte cultures were equally sensitive to SCE induction by methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), and N-hydroxy-2-acetylaminofluorene (N-OH-AAF). Analysis of different whole blood components showed that the presence of red blood cells (RBCs), and specifically RBC lysate, was a prerequisite for Na 2SeO 3 SCE induction in purified lymphocyte cultures. The SCE frequencies of xeroderma pigmentosum (XP12RO) and normal human lymphoblastoid cell lines were also found to be unaffected by Na 2SeO 3 concentrations that produced elevated SCE frequencies in whole blood cultures. Incubation of these latter two cell types with Na 2SeO 3 and RBC lysate resulted in SCE frequencines comparable to those in Na 2SeO 3-exposed whole blood cultures.