Induction of epithelial Na+ channel in rat ileum after proctocolectomy

Kaori Koyama, Iwao Sasaki, Hiroo Naito, Yuji Funayama, Kouhei Fukushima, Michiaki Unno, Seiki Matsuno, Hisayoshi Hayashi, Yuichi Suzuki

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

In patients with colectomy, epithelial transport function in the remnant small intestine can be regulated in response to the increased fecal electrolyte and fluid loss. Using a rat colectomy model, we investigated the Na+ and K+ transport mechanisms underlying the intestinal response. Proctocolectomy with ileoanal anastomosis was performed on rats. The small intestinal mucosa was mounted in Ussing chambers; then short-circuit currents and 22Na+ fluxes were measured, mRNA expression of the epithelial Na+ channel (ENaC) was determined by Northern blotting. Amiloride-sensitive, electrogenic Na+ absorption appeared in the ileum after prectocolectomy. This functional change was accompanied by the chronological induction of mRNAs for α-, β-, and γ-subunits of the ENaC in the ileum. Tetraethylammonium-sensitive short-circuit current was also activated. We conclude that electrogenic Na+ absorption and probably K+ secretion are induced in the ileum after proctocolectomy. This induction of electrogenic Na+ absorption is probably mediated by the increase in the mRNA levels for all three types of subunits of the ENaC and may contribute to the recovery from the increased fecal Na+ loss.

Original languageEnglish
Pages (from-to)G976-G984
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume276
Issue number4 39-4
DOIs
Publication statusPublished - 1999 Apr

Keywords

  • Aldosterone
  • Intestinal absorption
  • Intestinal adaptation
  • Potassium secretion
  • Sodium absorption

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)

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