INSULIN INCREASES EXPRESSION OF APOBEC-1, THE CATALYTIC SUBUNIT OF THE APOLIPOPROTEIN-B MESSENGER-RNA EDITING COMPLEX IN RAT HEPATOCYTES

We have previously shown that chronic insulin treatment of rat hepatoc ytes increases the fraction of edited apolipoprotein B (apoB) mRNA fro m approximately 50% to as much as 90%. We have now examined the effect of insulin on apobec-1 mRNA abundance and demonstrate that increased editing of apoB mRNA following insulin treatment is accompanied by ele vated apobec-1 mRNA levels in primary rat hepatocytes. Time-course mea surements of the effects of insulin on apoB mRNA editing and apobec-1 mRNA abundance showed that both were elevated almost maximally within 48 hours and sustained for at least 5 days of insulin treatment. Copyr ight (C) 1998 by W.B. Saunders Company.