The Effect Of PolyCHb Resuscitation On Pulmonary Tissue Of Hemorrhagic Shock Rats

Background:Hemorrhagic shock(HS)is a pathological state in which the blood volume of the body is sharply reduced,the oxygen supply/demand imbalanced,the anaerobic metabolism increased,and the cell function is impaired due to various causes such as trauma,restoring the circulating blood volume and the body oxygen supply balance are the key to treat HS.Currently,there was no ideal resuscitation fluid with oxygen-carrying function for the treatment of patients with HS.In our previous animal experiments,PolyCHb could improve the oxygen supply of ischemic tissue,microcirculation disturbance,and reduce the damage of HS intestinal tissue.However,there were few studies on the effects of lung tissue,so this topic was intended to be studied.Objective:Pressure-controlled HS rat model was used in this study to investigate the effects of PolyCHb after resuscitation on lung tissue oxidative stress,lung inflammatory and lung function.Methods:Wistar rats were subjected to hemorrhagic(the mean arterial pressure of 30-40 mmHg maintaining 90 min)and randomly divided into normal saline group,(2%,4%,6%)PolyCHb groups.Observing rat mean arterial pressure(MAP),heart rate(HR)and of baseline,shock,after 0 h and 6 h after resuscitaton,detecting the blood gas index and counting the value PaO2/FiO2.After all rats were sacrificed at 6 h after resuscitaton,testing the concentration of all protein in Bronchoalveolar lavage fluid(BALF),the value of lung wet/dry weight.Then,10%lung tissue homogenate was prepared to detect the level of Malondialdehyde(MDA),Superoxide Dismutase(SOD),Glutathine(GSH),Myeloperoxidase(MPO)and reactive oxygen species(ROS)to evaluate the level of oxidative stress of rat lung;to detect the counts of white blood cells and neutrophils in blood.The ELISA method was used to deter the level of tumor necrosis factor-?(TNF-?),interleukin-1?(IL-1?),interleukin-6(IL-6),interleukin-10(IL-10)in lung tissue and BALF,to evaluate the level of inflammatory response.Additionally the other part of lung was quickly incised to fix using 10%formaldehyde for the measurement of histopathologic changes.Results:The results showed that blood loss caused MAP and HR decreased.The MAP,HR and parts of blood gas indexes of the rats were recovered after fluid resuscitation.The MAP of the rats was slightly decreased at 6 h after resuscitation,which increased with the PolyCHb concentration.At 6 h after resuscitation,the protein concentration in BALF and lung wet-to-dry weight ratio also increased with the PolyCHb concentration,but the lung PaO2/FiO2 decreased with the increase of PolyCHb concentration.Moreover,the pathological section showed that the degree of lung tissue lesions increased with the concentration of PolyCHb.When PolyCHb was used to resuscitate hemorrhagic shock rats,GSH in lung tissue of low concentration(2%PolyCHb)was lower than that of NS group(P<0.05).Compared normal saline group,the PolyCHb groups' MPO activity,MDA concentration and ROS decreased;inflammatory cells such as white blood cells,neutrophils in blood were decreased,TNF-?,IL-1?,IL-6 in lung tissue and BALF were also decreased,but the level of IL-10 in lung tissue was increased.Conclusions:PolyCHb can effectively resuscitate hemorrhagic shock rats.When used low concentration PolyCHb for resuscitation,the oxidative stress response and the inflammatory response of lung tissue were low level,so it could reduce lung injury and slow down lung function.