Ischemic postconditioning does not attenuate ischemia-reperfusion injury of rabbit small intestine.
OBJECTIVE
To determine whether ischemic postconditioning can attenuate intestinal ischemia-reperfusion (I-R) injury and has a beneficial effect on tissue blood flow during reperfusion.


METHODS
In vivo experimental study.


METHODS
New Zealand White rabbits (n=6).


METHODS
Rabbits were anesthetized with pentobarbital, to avoid the preconditioning effects of volatile anesthetics, and ventilated with room air. Rectal temperature, hemodynamics, and normocapnia were maintained. After celiotomy, 3 jejunal segments were isolated in each rabbit for the following groups: (1) control, (2) I-R, and (3) I-R with postconditioning. I-R was induced by a 45-minute occlusion of the segment jejunal artery followed by 2-hour reperfusion. The postconditioning segment had 4 cycles of 30-second reperfusion and 30-second reocclusion during the initial 4 minutes of reperfusion. Stable isotope-labeled microspheres were used to measure intestinal blood flow at baseline, end occlusion, and end reperfusion. At the end of reperfusion, intestine segments were harvested and the rabbits euthanatized. A semiquantitative histopathologic evaluation (0-5) was conducted by a single, blinded observer. Wet-to-dry weight ratios were calculated to assess intestinal edema.


RESULTS
There was no significant difference in grade of necrosis, tissue wet-to-dry weight ratios, or blood flow at any time point between ischemic and postconditioning groups.


CONCLUSIONS
Ischemic postconditioning was ineffective in this model of intestinal I-R.


CONCLUSIONS
Further experimental studies will need to be performed before clinical application of postconditioning for intestinal ischemia.
Bretz
Brian
B
Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536, USA.
Blaze
Cheryl
C
Parry
Nicola
N
Kudej
Raymond K
RK
D000818:Animals; D006439:Hemodynamics; D007421:Intestine, Small / Q000098:blood supply / Q000473:pathology; D019194:Ischemic Preconditioning / Q000662:veterinary*; D007579:Jejunal Diseases / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary; D011817:Rabbits; D012039:Regional Blood Flow; D015427:Reperfusion Injury / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*