Tissue hypoxanthine reflects gut vulnerability in porcine endotoxin shock.
OBJECTIVE
To study differences in organ sensitivity during progressive endotoxin shock tissue levels of hypoxanthine, used as an indicator of adenosine triphosphate depletion and cellular energy failure, were monitored simultaneously in several organs by in vivo microdialysis.


METHODS
Prospective, controlled animal study.


METHODS
University research laboratory.


METHODS
Seventeen landrace pigs.


RESULTS
Tissue levels of hypoxanthine, assessed by in vivo microdialysis, were monitored (in the ileum, liver, lung, skeletal muscle, subcutaneous fat, and arterial blood) simultaneously in addition to central hemodynamics during endotoxin shock in ten pigs. Seven sham animals not receiving endotoxin served as controls. Marked changes were seen in central hemodynamic parameters in response to endotoxemia. Very prominent increases were seen in the ileum and liver, followed by the lung, whereas only limited changes were observed in subcutaneous fat. These results indicate a differentiated development of cellular energy failure in response to endotoxemia in different organs. By considering the high amounts of xanthine oxidase seen in the gut, the increases in hypoxanthine may provide an important substrate for reactive oxygen species formation in this organ. The limited changes seen in subcutaneous fat suggest that this tissue may provide limited sensitivity when monitoring the septic patient.


CONCLUSIONS
These findings support the concept of specific vulnerability of the gut during endotoxemia.
D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D016470:Bacteremia / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D004195:Disease Models, Animal; D018450:Disease Progression; D004731:Endotoxins / Q000009:adverse effects*; D006439:Hemodynamics; D019271:Hypoxanthine / Q000032:analysis* / Q000378:metabolism; D007082:Ileum / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008168:Lung / Q000737:chemistry; D017551:Microdialysis; D018482:Muscle, Skeletal / Q000737:chemistry; D011446:Prospective Studies; D017382:Reactive Oxygen Species / Q000378:metabolism; D012772:Shock, Septic / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D013552:Swine; D014018:Tissue Distribution