Disturbances in intestinal circulation for even short periods of time can produce mucosal injury, translocation of gut bacteria, and
multiple organ failure. We recently reported a model of intestinal
ischemia that included occlusion of the superior mesenteric artery (SMA) and interruption of collateral arcades from the right
colic and jejunal arteries for 20 min. This present study was designed to characterize further our model of intestinal
ischemia by quantitatively assessing changes in intestinal permeability (plasma to
luminal clearance of 51Cr-labeled
EDTA) and intestinal blood flow (IBF) (
microspheres). A total of 89 rats were included for study; mean arterial blood pressure and acid-base balance were not significantly altered by intestinal
ischemia or reperfusion. Baseline measurements of 51Cr-labeled
EDTA were not significantly different among the experimental animals, and clearance did not change throughout the experimental period in the
sham-ischemic group (N = 14). Clearance of 51Cr-labeled
EDTA at the end of 20 min of intestinal
ischemia (0.194 +/- 0.057 ml/min/100 gm, N = 17) was significantly greater than that measured at control (0.079 +/- 0.006 ml/min/100 gm, P less than 0.05). In addition, clearance measurements during reperfusion (20 min, 0.362 +/- 0.051; 60 min, 0.267 +/- 0.084 ml/min/gm) were significantly higher than those measured at the end of
ischemia. Baseline IBF was similar in all rats (N = 42); SMA occlusion reduced IBF by 99% from baseline (from 1.4 +/- 0.27 to 0.014 +/- 0.001 ml/min/gm, N = 20). Removal of the SMA
clip returned intestinal perfusion to baseline values (1.72 +/- 0.51 ml/min/g).(ABSTRACT TRUNCATED AT 250 WORDS)