The Changes Of S100B Protein In Brain Tissue Of Rats With Hemorrhagic Shock Following Limited Fluid Resuscitation

Background Hemorrhagic shock is one of the severe clinically issues which also is one of the main reasons that leading patients with serious trauma to death. The most effective treatment for patients with hemorrhagic shock is stop bleeding by surgery and administration of fluid resuscitation immediately. Fluid resuscitation is particularly important to provide blood and oxygen for vital organs of these patients which could lay the foundation for further effective treatment for the injured patients. But clinical studies in recent years have found that large doses of fluid resuscitation before the treatment of effective hemostasis will produce a number of adverse reactions in patients, so the treatment of limited fluid resuscitation for hemorrhagic shock is promoted gradually. Limited fluid resuscitation for patients of traumatic hemorrhagic shock without control the bleeding provides a new mode of treatment which can be effective in reducing re-bleeding of wounds, stabilization hemodynamics in patients, lowering the injury of ischemia-reperfusion in organs.S100B is a small molecule of calcium-binding protein secreted and expressed by central nervous system which is one of the serological markers for traumatic brain injury. Studies have found that not only chronic cerebral hypoperfusion that damage hippocampus cells could lead the increase of serum S100B protein concentration, but acute hemorrhagic shock caused by acute systemic bleeding could lead the increase of serum S100B protein concentration too. acute hemorrhagic shock is related to acute hypoperfusion of brain tissue, limited fluid resuscitation could control the blood pressure in the lower range during the recovery. However, it is still rare for researches focus on whether S100B protein could reduce the ischemia reperfusion injury in brain tissue and the relationship between S100B protein and ischemia reperfusion injury in brain tissue. Therefore, this study is focus on the changes of S100B protein in brain tissue of rats with hemorrhagic shock following limited fluid resuscitation by using rat model of hemorrhagic shock created by Capone.Objective To investigate the effects of limited fluid resuscitation on the impact of S100B protein tested in rat brains with hemorrhagic shock and uncontrolled bleeding.Methods60healthy, male, clean grade SD rats were selected and divided randomly into blank control group(n=6), sham-operated group(SO group n=18), limited fluid resuscitation group(LR group n=18), conventional fluid resuscitation group(CR group n=18). The model of hemorrhagic shock we adopted was created by Capone et al. Blank control group received no treatment of anesthesia and surgical. SO group was subjected to insert catheters into left and right femoral artery and right femoral vein after anesthesia, after the blood pressure is stable for last10minutes, we recorded the parameters and sacrificed the rats at the3time points. Rats in LR group and TR group were underwent the model of hemorrhagic shock uncontrolled bleeding, then limited fluid resuscitation, conventional fluid resuscitation were administrated for these2groups respectively. First aid60min by fluid resuscitation, then hemostasis by tail artery ligation and liquid recovery for120min, at the stage of observation, rats were sacrificed in batches at the time points of1hour,6hours and12hours after anesthesia. The content of S100B protein, AGER protein, total superoxide dismutase (T-SOD), malondialdehyde (MDA) and myeloperoxidase (MPO) in rats were tested by different kits.Results 1) After different treatments in rats with hemorrhagic shock.1hour after the stage of observation, The content of S100B protein in LR group and TR group are much higher than SO group(P<0.01), but there is no significant statistically differences between LR Group and TR group (P=0.067).6hours and12hours after observation, the comparison of S100B protein content between LR group, TR group and SO group is:TR group> LR group> SO group, and the difference is statistically significant.2) With the extension of time in shock and resuscitation in the first hour of the observation period, the content of AGER in brain tissue of rats in TR group was higher than LR group and SO group, the difference was statistically significant (p <0.01).6hours and12hours after the fluid resuscitation, the comparison of S100B protein content between LR group, TR group and SO group is:TR group> LR group> SO group(p<0.01). The content of AGER protein in all groups was increased by time. The content of AGER protein in12hours sub-group from SO group was higher than1hour sub-group (p=0.034), while the content of AGER protein in LR group TR group was elevated gradually with the extension of time(p <0.01).3)1hour,6hours and12hours after the fluid resuscitation at the stage of observation, the comparison of MDA content in brain tissue of rats between these groups was LR group> TR group> SO group, and the difference was statistically significant (P<0.01). the MDA content in brain tissue of rats in SO group was increased with the extension of time after the resuscitation, but the MDA content in LR group and TR group were decreased, and the difference is statistically significant (P<0.05).4)1hour,6hours and12hours after the fluid resuscitation at the stage of observation, the comparison of T-SOD content in brain tissue of rats between these groups was SO group> LR group> TR group, and the difference was statistically significant (p<0.01), but there was no significant statistically differences between each sub-groups from SO group with the comparison of T-SOD content in rats brain tissue at different time points. However, the T-SOD brain tissue of rats from LR group and TR group were increased gradually with the extension of time after the resuscitation, and this trend was statistically significant (p<0.01).Conclusion1) The treatment of limited fluid resuscitation could slow the uptrend of S100B protein expression in brain tissue of rats with hemorrhagic shock compared to the conventional fluid resuscitation.2) The expression of S100B protein may correlates with the level of oxidative stress or ischemia reperfusion injury in brain tissue.