Submitted on April 11, 2006
Accepted on May 30, 2006
HIBERNATION CONFERS RESISTANCE TO INTESTINAL ISCHEMIA-REPERFUSION INJURY
Courtney C. Kurtz1, Susanne L. Lindell1, Martin J. Mangino2, and Hannah V. Carey1*
1 Comparative Biosciences, University of Wisconsin, Madison, Wisconsin, United States
2 Surgery, University of Wisconsin, Madison, Wisconsin, United States
* To whom correspondence should be addressed. E-mail: careyh{at}vetmed.wisc.edu.
The damaging effects of intestinal ischemia/reperfusion (I/R) on the gut and remote organs can be attenuated by subjecting the intestine to a prior, less severe I/R insult, a process known as preconditioning. Because intestines of hibernating ground squirrels experience repeated cycles of hypoperfusion and reperfusion, we examined whether hibernation serves as a model for natural preconditioning against I/R-induced injury. We induced intestinal I/R in either the entire gut (SMA I/R) or in isolated intestinal loops using rats, summer ground squirrels and hibernating squirrels during natural interbout arousals (IBA; Tb 37-39°C). In both models, I/R induced less mucosal damage in IBA squirrels than in summer squirrels or rats. SMA I/R increased myeloperoxidase (MPO) activity in gut mucosa and lung of rats and summer squirrels and liver of rats, but had no effect in IBA squirrels. I/R in isolated loops increased luminal albumin levels, suggesting increased gut permeability in rats and summer squirrels but not IBA squirrels. The results suggest that the hibernation phenotype is associated with natural protection against intestinal I/R injury.
