Regional difference in intestinal adaptation after total colectomy as judged by the changes of mucosal Na-K ATPase, cyclic AMP, and transmural potential difference.

Abstract

Intestinal adaptation and its regional difference after total colectomy were investigated in dogs by measuring mucosal Na-K ATPase, cyclic AMP, and transmural electric potential difference (PD). Twenty-four weeks after the total proctocolectomy, Na-K ATPase activity and PD increased significantly in all intestinal sites, whereas cyclic AMP showed no significant changes. The regional difference in the remaining intestine was examined in the jejunum, ileum, and interposed jejunum (neorectum). Na-K ATPase activity showed no significant regional difference, but the largest increase was found to occur in the ileum. PD also increased markedly in the ileum and there was significant difference between the ileum and other intestinal sites. These facts suggest that the increased active ion transport mediated by mucosal Na-K ATPase and transmural PD in the ileum is closely related to the intestinal adaptation occurring after total colectomy and indicates a greater potential of the ileum for adaptive compensation than either jejunum or neorectum.