The Expression Of Aquaporins In Different Crystalloid-colloid Ratios By Goal-directed Fluid Therapy In Dogs With Hemorrhagic Shock

Objective:To investigate the expression of aquaporins in different crystalloid-colloid ratios by goal-directed fluid therapy in dogs with hemorrhagic shock.Methods:30healthy beagle dogs were established hemorrhagic shock model with the modified Wigger's method and then randomly divided into5groups (n=6) according to different crystalloid-colloid ratios goal-directed fluid therapy:3:1group,2:1group,1:1group,1:2group and1:3group. Stroke volume variation (SVV)below13%was regared as targeted goal, a fluid bolus4ml/kg of different crystalloid-colloid ratios was administered within10mins when SVV exceed13%. Autologous blood was infused and maintenanced the hemoglobin between90to110g/L. After4hours of resuscitation, these animals were sacrificed with euthanasia. Lung tissue and colon tissue were collected and stained by immunohistochemistry to deteceted the expression of aquaporins (AQPs). Lung tissue and colon tissue were measured and analyzed aquaporins positive unit on positive cell. Lung tissue and colon tissue were measured wet/dry weight ratio.We recorded and compared the results of the arterial blood gas measurement and coagulation function test, calculated and compared the fluid volume and the urine output.Results:(1) In lung tissue, AQP1showed expression with moderate or large degree in bronchial basement membrane, AQP5showed a moderate amount to a large of expression in alveolar and lung bronchial epithelium. The five groups are significant differences in average positive unit of AQP1and AQP5,1:3group express obviously increased (the average positive unit of AQP1is59.22±10.25, and the average positive unit of AQP5is53.24±10.77).(2) In colon tissue, AQP1showed expression with a moderate degree in colonic mucosa glands, AQP3showed a moderate amount of expression by colonic mucosa glands, neuroendocrine-like cells. These five groups are significant differences in average positive unit of AQP1and AQP3. In1:3group, AQP1express obviously rised (the average positive unit is46.82±3.48), thus in1:2group, AQP3express significantly climped (the average positive unit is43.39±2.09).(3) In the process of resuscitation, these five groups are significant difference in the average time of SVV arrived standards. With the proportion of crystalloid reduced and colloid increased gradually, the average time of SVV arrived standards was gradually shortened (1:3group is58.33±10.39min;3:1group is91.50±23.65min).(4) In these five groups, the average fluid volume was significant difference, the average infusion rate during resuscitation was significant difference, and there was no significant difference in urine output.Conclusion:(1) In the group of colloid-based fluid therapy, AQPs showed expression with moderate or large degree in lung tissue and colon tissue.(2) AQPs may involed in the fluid transportion during resuscitation of hemorrhagic shock, colloid may give rise to increase of the expression of AQPs during fluid resuscitation of hemorrhagic shock.(3) In the goal-directed fluid therapy by different crystalloid-colloid ratios, colloid-based fluid therapy was superior to crystalloid-based fluid therapy on the fluid volume, the average recovery of infusion rate and the recovery of blood lactate acid.(4) In the process of resuscitation, with the proportion of crystalloid reduced and colloid increased, the average time of SVV arrived standards was gradually shortened.(5) SVV is an useful predictor of fluid therapy in hemorrhagic shock.