Effect of a hyperosmolar solution on the small intestine of newborn rats: irreversible damage and overgrowth of bacteria

Abstract

The effect of a hyperosmolar solution (gastrografin, Schering, 1,750 mosm/l) on the gastrointestinal (GI) tract of newborn Wistar rats was studied. The rats received an inoculum of Klebsiella bacteria on the 1st day of life, following which gastrografin was given twice daily via an orogastric tube. All the rats receiving gastrografin showed GI symptoms from the 3rd day of life, and 80% died before completion of the experiment on the 7th day. Macroscopic and microscopic examination of the GI tract revealed gross changes confined to the small intestine. Specimens from stools and peritoneal cavity for culture of Klebsiella obtained immediately after killing were positive in the rats that had received gastrografin. Control rats had no GI symptoms and showed normal findings at autopsy; cultures obtained from stools and peritoneal cavity were all negative. This experiment indicates that in newborn rats a continuous hyperosmolar load in the GI tract causes irreversible damage to the small intestine; promoting the growth of pathogenic bacteria and providing a means for translocation of the micro-organisms to the abdominal cavity.