Hemorrhagic shock induces predominant damage to the proximal small intestine in the mouse

A variety of stress‐states cause intestinal mucosal damage. Hemorrhagic shock (HS) is known to do so via reductions in intestinal blood flow, resulting in ischemia. This study had two objectives: first, we evaluated whether an acute hemorrhagic shock model in the mouse induced intestinal damage; second, we determined if there existed regional susceptibilities to injury as those we previously identified in another stress condition, hyperthermia. In lightly anesthetized C57BL/6 mice, 30% of their blood volume was removed by transthoracic intracardiac puncture. Withdrawn blood was kept at 37°C for 60 min and re‐injected through the retro‐orbital sinus under anesthesia. The animals recovered for another 60 min, were then re‐anesthetized, a second blood draw performed and intestines harvested and fixed for later histological evaluation. Significant histological damage was observed in the duodenal (DU) intestine in HS vs. sham control (P < 0.02), with no significant damage seen in the jejunum (JE) or Ilium (IL). The DU in HS animals also exhibited significant reductions in villus height and total mucosal thickness (P < 0.003, P< 0.003 respectively). There were no effects of HS on average villus width or crypt depth. Results demonstrate that in acute HS in the mouse, regions of the intestine near the stomach are most vulnerable to damage within one hour, post HS. The pronounced shortening of the villi observed at this time likely reflects ongoing intestinal repair strategies that are used to remove damaged epithelium. AHA #11GRNT7990119