Effect of Klebsiella pneumoniae enterotoxin on intestinal transport in the rat

Abstract

The infects on intestinal transport of either a semipurified preparation of enterotoxin elaborated by Klebsiella pneumoniae or similarly prepared control material were tested by marker perfusion studies in the small intestine of rats. At a concentration of 2 mg/ml, the enterotoxin produced net secretion of water, Na, and Cl in both jejunal and ileal segments; HCO3 transport was not affected. Net secretion was evident within 30 min after introduction of the toxin and was maximal after 90 min. The addition of 56 mM glucose to the enterotoxin containing perfusion fluid resulted in reversal of water and Na transport to net absorption in both intestinal segments. The enterotoxin also produced a significant depression of xylose absorption in both the jejunum and ileum but did not affect the absorption of either glucose or L leucine. Intestinal structure was not altered after perfusion of the toxin but instillation of approximately one quarter of the total perfusion dose into a ligated jejunal loop for 18 h produced fluid secretion and structural abnormalities. These observations confirm the fact that other species of coliform bacteria in addition to Escherichia coli are capable of elaborating an enterotoxin. Such species commonly contaminate the small intestine of persons with tropical sprue and it is suggested that chronic exposure of the intestinal mucosa to the enterotoxin elaborated by these bacteria may be a factor in the pathogenesis of intestinal abnormalities in this disorder.