EFFECTS OF ENTERIC MICROBIAL OVERGROWTH ON SMALL INTESTINAL ULTRASTRUCTURE IN RAT

  • 1 January 1978
    • journal article
    • research article
    • Vol. 70  (3) , 249-258
Abstract
Ultrastructural effects of bacterial proliferation in the upper gastrointestinal tract induced by i.p. injections of mecamylamine HCl were investigated in rats. Increased populations of nonspecific enteric bacteria were found in the lumen of the upper small intestine and ultrastructural abnormalities in the absorptive epithelial cells, including increased numbers of lysosomal vacuoles, fused microvilli and dilated endoplasmic reticulum. The bacteria did not penetrate into the damaged mucosal cells and so cytoplasmic infiltration is not required to cause ultrastructural changes. Alterations were not merely due to the pharmacologic agent used. Rats with subnormal numbers of enteric bacteria in the upper small intestine, whether subjected to the course of the drug or not, did not display observed ultrastructural changes. Concomitant with increased numbers of enteric bacteria in the small intestine, there were increased concentrations of deconjugated bile salts and decreased absorption of glucose. Apparently the hypothetical sequence of pathogenesis is mecamylamine, intestinal stasis, bacterial overgrowth, deconjugation of the bile salts and ultrastructural alterations.