Effect of hypertonic saline resuscitation on heme oxygenase-1 mRNA expression and apoptosis of the intestinal mucosa in a rat model of hemorrhagic shock.

Background: Massive blood loss due to trauma is the leading cause of death in trauma patients and military combatants. The fluid category of resuscitation for hypotensive trauma patients is open to debate. This study was conducted to investigate the early effects of hypertonic and isotonic saline solutions on heme oxygenase-1 (HO-1) mRNA expression and apoptosis in the intestinal mucosa of rats with hemorrhagic shock.

Methods: A model of severe hemorrhagic shock was established in 21 Sprague-Dawley rats. The rats were randomly divided into sham, normal saline resuscitation (NS), and hypertonic saline resuscitation (HTS) groups, with 7 in each group. We assessed and compared the HO-1 mRNA expression and apoptosis in the small intestinal mucosa of rats after hemorrhagic shock and resuscitation using the SYBR Green I fluorescence quantitative reverse transcriptase polymerase chain reaction, fluorescein-iso-thiocyanate-annexin V/propidium iodide double staining, and flow cytometry.

Results: In the early stage of hemorrhagic shock and resuscitation, marked apoptosis occurred in the small intestinal mucosa from both the NS and HTS groups. The apoptotic rate in the NS group was higher than that in the HTS group (P < 0.01). Among the three groups, HO-1 mRNA mucosa from the HTS group had the highest level of expression; however, the differences were not significant. There was a significant negative correlation between HO-1 mRNA expression and apoptosis in the small intestinal mucosa from the NS and HTS groups after hemorrhagic shock and resuscitation.

Conclusions: In this rat model of severe hemorrhagic shock, HTS resuscitation with a small volume is more effective than NS resuscitation in reducing apoptosis of the intestinal mucosa. Further, HO-1 mRNA over-expression in the intestinal mucosa may be one of the molecular mechanisms of HTS in the resuscitation of hemorrhagic shock.