Difflerent IntestinalResponses of Apoiipoprotein A - I , A - IV , and B Gene Expression Adaptation to a Massive Smal } Bowel Resection in Rats during

Gene expression et' apolipeproteins (apo) A-l, A-IV, and B, the predominant pretein components of chylomicr{}ns, was in\estigated in the residual ileum after a massive small bowel resection in rats. A Northern blot analysis showed that the apo A-IV mRNA leyel, but not the apo A-I and B mRNA leyels, in the ileum was significantiy higher in the resected rats than in the sham-operated rats 24h and 2wk post-surgery. RT-PCR ¢ oupied with a primer extension assay revealed that the apo B-48 mRNAfapo B-100 mRNA ratio, i.e., apo B mRNA editing, in the ielum was unchanged by the resection. Jt is thus concluded that, among the major intestinag polipeprateins, apo A-IV is the only one whose gene expression is influenced by loss of the proximag intestine.