Figure 4.

Dicoumarol inhibits p53 accumulation and p53-dependent apoptosis in γ-irradiated thymocytes. Thymocytes that were not irradiated (−) or were γ-irradiated at 4 Gy (+) were cultured for 5 h without (−) or with 100 and 200 μM dicoumarol. (A) The percentage of apoptotic cells was determined on May–Grünwald–Giemsa-stained cytospin preparations. (B) DNA fragmentation at internucleosomal sites. (C) Immunoblot analysis was carried out with Pab 240 monoclonal anti-p53 antibody. Dic., dicoumarol; γ-irr., γ-irradiation.