Regulation of hepatic apolipoprotein B RNA editing in the genetically obese Zucker rat.

Hepatic apolipoprotein (apo) B RNA editing was examined in the genetically obese hyperinsulinemic and hypertriglyceridemic Zucker rat. In obese Zucker rats, apo B RNA editing was increased 42% relative to that in lean controls. Correspondingly, the proportion of serum triglyceride-rich lipoprotein containing apo B48 increased 4.7-fold in the obese Zucker rat. Quantification of hepatic total apo B mRNA showed no difference between obese Zucker and lean control rats. In contrast, the hepatic mRNA encoding APOBEC-1, the catalytic subunit of the RNA editing activity, demonstrated an increased abundance of 1.8-fold in obese Zucker rats versus lean controls.