The effect of dexamethasone administration on rat intestinal permeability: the role of bacterial adherence.
OBJECTIVE
Previous studies have shown that dexamethasone administration to rats results in diminution of biliary secretory immunoglobulin A concentration and alters intestinal barrier function to bacteria. The aims of this study were to examine and characterize the effect of dexamethasone on intestinal permeability and to determine the possible influence of bacterial adherence to the mucosa in this process.


METHODS
Groups of adult Fisher rats were studied, and the effects of dexamethasone administration and bowel decontamination on bacterial adherence and intestinal permeability were determined in various bowel segments.


RESULTS
Dexamethasone administration was associated with a significant increase in bacterial adherence to the mucosa, which was most pronounced in the cecum (4.33 +/- 0.2 colony forming units (cfu) (log10) per gram of mucosa for control vs. 6.23 +/- 0.2 for dexamethasone). This was accompanied by significant alterations in intestinal permeability as measured by a decrease in transepithelial electrical resistance (49.5 +/- 4.1 omega.cm2 for control vs. 25.4 +/- 2.5 omega.cm2 for dexamethasone). Dual sodium-mannitol flux analysis showed this defect to be predominantly paracellular. Antibiotic decontamination of the intestine completely abrogated the intestinal permeability defect observed in this model.


CONCLUSIONS
Bacterial-mucosal cell interactions may be responsible for alterations in intestinal permeability after dexamethasone administration.
Spitz
J
J
Department of Surgery, University of Illinois, Chicago.
Hecht
G
G
Taveras
M
M
Aoys
E
E
Alverdy
J
J
D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology*; D002939:Ciprofloxacin / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D004553:Electric Conductivity; D005260:Female; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D010539:Permeability; D051381:Rats; D011916:Rats, Inbred F344
D002939:Ciprofloxacin; D003907:Dexamethasone