Colon ASBT mRNA expression in CIE vs controls?

• A. Higher
• B. Lower
• C. Not different
• D. Not detected

Answer: (C)

The question examines how inflammatory disease affects expression of a bile acid transporter in the colon. ASBT is the transporter that reclaims bile acids mainly in the ileum, and its colonic mRNA expression is typically low and not strongly regulated by colonic inflammation. If chronic inflammatory enteropathy does not alter the transcription of ASBT in the colon, you would observe similar mRNA levels in affected dogs and healthy controls. So, not different is the best answer because colonic ASBT transcription remains unchanged despite CIE, reflecting the limited role of the colon in ASBT-mediated bile acid reabsorption and the segment-specific regulation of this transporter. Remember that mRNA levels don’t always equal protein activity, but the data here point to no transcriptional difference in the colon.