Endotoxin-induced ileal Vo2-Do2 alterations do not correlate with the severity of ileal injury.
OBJECTIVE
Altered Vo2-Do2 relationships are most often noted to occur in the setting of sepsis or endotoxin (LPS)-induced systemic organ microvascular injury and are generally thought to be causally linked to that injury. However, we have recently shown that ileal microvascular injury is not associated with altered ileal Vo2-Do2, relationships. Thus, we hypothesized that the severity of LPS-induced systemic organ microvascular injury would not correlate with the development of systemic organ Vo2-Do2 alterations.


METHODS
To test this hypothesis, we used the in situ autoperfused feline ileal preparation to simultaneously examine microvascular permeability, reflected as the ileal lymph to plasma protein concentration ratio (CL/CP), and ileal Vo2-Do2 relationships 2 hours after intravenous LPS (0.75-2.0 mg/kg; n = 9) and in matching controls (n = 5).


RESULTS
As expected, all LPS-treated animals were found to have extensive ileal histological damage and marked increases in the CL/CP compared with controls (0.308 +/- 0.019 v 0.097 +/- 0.009; P < .001). In addition, although the critical Do2 (Do2c) was elevated in the LPS-treated animals relative to controls (34.2 +/- 5.0 v 16.7 +/- 1.4 mL/min/kg; P < .03), there was no correlation between the Do2c and the CL/CP in the LPS-treated animals. Finally, ileal wet to dry weight ratios after LPS did not differ from controls.


CONCLUSIONS
Taken together, these data suggest that factors other than organ injury, as assessed by morphological and permeability alterations, are important in the pathogenesis of altered systemic organ Vo2-Do2 relationships after LPS.
Crouser
E D
ED
Department of Internal Medicine, Ohio State University, Columbus 43210, USA.
Julian
M W
MW
Weisbrode
S E
SE
Dorinsky
P M
PM
D000818:Animals; D001784:Blood Gas Analysis; D001798:Blood Proteins / Q000032:analysis; D002199:Capillary Permeability; D002415:Cats; D004731:Endotoxins / Q000378:metabolism*; D006439:Hemodynamics; D007082:Ileum / Q000098:blood supply* / Q000293:injuries* / Q000648:ultrastructure; D008297:Male; D010101:Oxygen Consumption; D012720:Severity of Illness Index
D001798:Blood Proteins; D004731:Endotoxins