Gut barrier dysfunction as detected by intestinal luminal microdialysis.
OBJECTIVE
To evaluate the use of gut luminal microdialysis as a tool for monitoring ischaemic metabolites, particularly glycerol, as markers of intestinal dysfunction during and after intestinal ischaemia.


METHODS
A randomised, controlled animal experiment.


METHODS
National laboratory animal centre.


METHODS
In seven pigs the thoracic aorta was cross-clamped for 60 min followed by 2 h of reperfusion, while five pigs served as controls.


RESULTS
Glycerol, lactate and glucose in the intestinal lumen and mucosa were measured by microdialysis. Intestinal tissue blood flow was determined by means of colour-labelled microspheres. To assess intestinal permeability, (14)C-polyethylene glycol 4000 (PEG-4000) was instilled in a jejunal segment and then measured in venous blood. Intestinal blood flow was reduced to 10% of baseline by aortic cross-clamping ( p=0.001) and returned to baseline during reperfusion. Intestinal luminal lactate increased during ischaemia and further increased during reperfusion. The increase was paralleled by augmented intestinal permeability; there was a significant correlation between luminal lactate and venous PEG-4000 ( r=0.89, p<0.01). Aortic cross-clamping caused a marked increase in intestinal mucosal glycerol concentrations, which correlated with luminal glycerol during both ischaemia and reperfusion ( r=0.85, p<0.01).


CONCLUSIONS
Microdialysis of lactate may be useful for monitoring intestinal ischaemia and reperfusion. Release of lactate into the intestinal lumen appears to be related to increased permeability. Intestinal luminal glycerol closely mirrored glycerol concentrations in the intestinal wall.
Department of Anaesthesiology and Intensive Care, St. Olav University Hospital, Norwegian University of Science and Technology, 7006 Trondheim, Norway. erik.solligard@medisin.ntnu.no
Erik
E
Solligård
Ingebjørg S
IS
Juel
Karin
K
Bakkelund
Harald
H
Johnsen
Ola D
OD
Saether
Jon Erik
JE
Grønbech
Petter
P
Aadahl
D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000098:blood supply / Q000378:metabolism*; D007422:Intestines / Q000098:blood supply*; D007511:Ischemia / Q000175:diagnosis / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D017551:Microdialysis; D010539:Permeability; D012039:Regional Blood Flow; D015427:Reperfusion Injury / Q000175:diagnosis / Q000378:metabolism; D013552:Swine
D015415:Biomarkers; D019344:Lactic Acid; D005947:Glucose; D005990:Glycerol