Polypeptide composition of nuclear envelope following thioacetamide-induced nuclear swelling

Nuclear envelopes (NE) were isolated from rat liver following thioacetamide-induced nuclear swelling. At 8 and 48 h intervals following thioacetamide treatment, periods which correspond to nuclear swelling phases, NE showed little change in polypeptide composition (although the polypeptide composition depended to some extent upon the isolation procedure used). Since the amount of NE protein increases by 30–40% and 70–80% at these times (respectively), the data suggest that concerted synthesis of a number of NE polypeptides occurred. We propose that triggered expansion of the NE may be an important first stage in the action of carcinogens.