International Journal of Colorectal Disease

, 21:357

Segmental heterogeneity of electrogenic secretions in human ascending colon and rectum

Authors

  • Jung Ho Park
    • Department of Medicine, Kangbuk Samsung HospitalSungkyunkwan University School of Medicine
    • Department of Medicine, Samsung Medical CenterSungkyunkwan University School of Medicine
  • Jun Haeng Lee
    • Department of Medicine, Samsung Medical CenterSungkyunkwan University School of Medicine
  • Jae Jun Kim
    • Department of Medicine, Samsung Medical CenterSungkyunkwan University School of Medicine
  • Jong Chul Rhee
    • Department of Medicine, Samsung Medical CenterSungkyunkwan University School of Medicine
  • Sung Joon Kim
    • Department of Physiology, Samsung Medical CenterSungkyunkwan University School of Medicine
  • Jiyeon Lee
    • Biomedical Research Institute, Samsung Medical CenterSungkyunkwan University School of Medicine
Original Article

DOI: 10.1007/s00384-005-0034-0

Cite this article as:
Park, J.H., Rhee, P., Lee, J.H. et al. Int J Colorectal Dis (2006) 21: 357. doi:10.1007/s00384-005-0034-0

Abstract

Aims

We have attempted to ascertain putative segmental differences in the secretory responses of the human ascending colon and rectum.

Methods

From the mucosal biopsy samples of two segments, the short-circuit current (Isc) and tissue resistance (Rte) were compared under control conditions, as well as after the induction of secretion, using a modified Ussing chamber. We also performed semiquantitative reverse transcriptase–polymerase chain reaction (RT-PCR) to detect and quantify transport proteins.

Results

The spontaneous Isc in the ascending colon was found to be greater than that in the rectum (P<0.01), whereas isobutylmethylxanthine/forskolin and carbachol (CCh) induced a greater rise in Isc in the rectum than in the ascending colon (P<0.05). When coupled with indomethacin pretreatment, the increase in ΔIsc after the addition of CCh and forskolin was significant as compared to that observed without pretreatment (P<0.05). However, in the rectum, the secretory response to CCh and forskolin was abolished to a significant degree by indomethacin (P<0.05). Moreover, these indomethacin-induced changes were reversed by the addition of PGE2. Upon semiquantitative RT-PCR analysis, the amounts of cystic fibrosis transmembrane regulator, KCNQ1, and CLCA1 mRNAs were not found to be different between the two segments.

Conclusion

There was a clear segmental heterogeneity with regard to electrogenic secretion in the human colon, and this difference can be explained by differences in the ascending colon and rectum.

Keywords

Segmental heterogeneityUssing chamberRT-PCRHuman colon

Copyright information

© Springer-Verlag 2005