Effect Of Resuscitation After Selective Cerebral Ultra-deep Hypothermia Blood Flow Occlusion On Caspase-9 And S100B: An Experimental Study On Monkeys

【Objective】To observe the expression of Caspase-9 and S100B in monkeys ofresuscitation after selective cerebral ultra-deep hypothermia and blood flow occlusion.【Method】Nine 4～10-year-old rhesus mulattas were divided randomly into twogroups: group A (bilateral internal carotid arterys would be occluded and 37℃Ringer'ssolution would be infused in operation) and group B (bilateral internal carotid arteryswould be occluded and 4℃Ringer's solution would be infused in operation). Exposedbilateral external jugular veins (EJVs), bilateral external carotid arterys (ECAs),bilateral internal carotid arterys (ICAs) and bilateral internal jugular veins (IJVs). RightIJV intubated to monitoring central venous pressure (CVP). A catheter was inserted intoright ICA to infuse cold Ringer's solution, two catheters were distally and proximallyinserted into IJVs to extract the hypothermic diluted blood for ultrafiltration and thenperfuse the warm blood into the fight venae cava inferior after rewarming. Total bodywas heparinizated before reduce the brain temperature. Both ICAs were clamped 10minutes. Then the both EJVs and the left IJV were clamped about 60 minutes. 4℃coldRinger's solution was immediately perfused into the right ICA to induce the braincooling less 16℃in group B, 37℃Ringer's solution was immediately perfused intothe right ICA in group A. After 60 minutes, perfusion was stopped and blood vesselswere recovered blood stream to cause brain physio-rewarming in group B, it didn'toccur in group A of course. During preoperative and postoperative course, MRJ scanswere obtained and changes of hemodynamics were measured; the afunctional scales ofneurology were done three days after operation. The monkeys' brain was immediatelyremoved soon after death of group A in operation, and so did it in group B after weexecuted the monkeys 12 weeks after operation, followed by fixation, dehydration,embedding with paraffin and section. Immunohistochemical technique was used todetermine frontal cellular expression of Caspase-9 and S100B in respective group.Statistics were analyzed by ANOVA analyses with significance level at P＜0.05. 【Results】All monkeys of group A were not resuscitation after perfusion and died.The level of Caspase-9 and S100 Bprotein expression were overly high in group A. Allmonkeys of group B were succeeded in being built up the model. The hemodynamicalparameters were steady during the operation, and all of them lived up till they wereexecuted. MRI scan was normal after operation and the function of neurologicaldeficient scale was normal. The level of Caspase-9 and S 100B protein expression wereboth significantly lower in the group B than those in the group A (P＜0.05).【Conclusion】It is safety that monkeys resuscitate from selective cerebral ultra-deephypothermia and blood flow occlusion of bilateral internal carotid for 60 minutes, and itis normal to the hemodynamical parameters and nervous function. The level ofCaspase-9 and S100B protein expression aer significantly decreased after resuscitationafter selective cerebral ultra-deep hypothermia and blood flow occlusion. It is anendogenous self-protective mechanism for helping to maintain neuron survival and torecover neural function. To most extent, mild cerebral ischemic lesion lead to neurocyteapoptosis and serious cerebral ischemic lesion lead to neurocyte necrosis.