AJP - Gastrointestinal and Liver Physiology, Vol 245, Issue 1 122-G132, Copyright © 1983 by American Physiological Society
Altered jejunal macromolecular barrier induced by alpha-dihydroxy deconjugated bile salts
S. Teichberg, E. McGarvey, M. A. Bayne and F. Lifshitz
The effect of deconjugated bile salt hydroxy group position and numbers on
the ability of these agents to alter the normal lumen-to-blood jejunal
barrier to intact protein penetration was analyzed. Only in vivo jejunal
perfusion with 0.5 mM alpha-dihydroxy deconjugated bile salts
chenodeoxycholate and deoxycholate led to increased penetration of the
40,000-molecular-weight protein horseradish peroxidase (HRP). This
increased absorption of HRP with 0.5 mM chenodeoxycholate and deoxycholate
was detectable biochemically, as well as by light and electron microscopic
cytochemistry, and occurred in the absence of demonstrable histological or
ultrastructural damage to the epithelium. Conjugation of chenodeoxycholate
with glycine, epimerization of chenodeoxycholate from 7 alpha-hydroxy to 7
beta-hydroxy as in ursodeoxycholate, or addition of a third hydroxyl group
as in cholate all eliminated the increase in jejunal HRP penetration and
led to HRP absorption levels like those in bile salt-free preparations. The
effect of chenodeoxycholate and deoxycholate on HRP absorption was
paralleled by their production of net jejunal water secretion. The
observations suggest that the naturally occurring alpha-dihydroxy bile
salts may lead to an increase in intact antigen or toxin absorption during
bacterial stasis syndromes.
