高压氧预处理对窒息性心脏停搏复苏大鼠血浆蛋白质C活化的影响

Effect of hyperbaric oxygen preconditioning on activation of plasma protein C in a rat model of asphyxial cardiac arrest-resuscitation

目的探讨高压氧预处理对窒息性心脏停搏复苏大鼠血浆蛋白质C活化的影响。方法清洁级健康成年雄性SD大鼠105只，70～90日龄，体重260～320g，采用随机数字表法分为3组：心脏停搏组（CA组，n=5）、心脏停搏复苏组（CA／R组，n=50）和高压氧预处理组（H组，n=50）。采用呼气末夹闭气管窒息法建立大鼠心脏停搏复苏模型。H组给予连续3d高压氧预处理（纯氧舱压力2个绝对大气压力，稳压吸氧45min，控制氧浓度〉95％后，20min匀速降压至常压，1次／d）后制备心脏停搏复苏模型。CA组不进行复苏。CA／R组和H组于自主循环恢复后3、6、12和24h时随机取5只大鼠，CA组于心脏停搏30min时，经腹主动脉取血标本5ml，采用ELISA法测定血浆活化的蛋白质C（APC）浓度，记录窒息至心脏停搏时间、自主心率恢复时间和复苏成功情况。结果与CA组比较，CA／R组和H组自主循环恢复后各时点血浆APC浓度降低（P〈0．05）；与CA／R组比较，H组窒息至心脏停搏时间延长，自主心率恢复时间缩短，复苏成功率升高，自主循环恢复后各时点血浆APC浓度升高（P〈0．05）。结论高压氧预处理可促进窒息性心脏停搏大鼠复苏后血浆PC活化，有助于改善高凝状态。

Objective To investigate the effect of hyperbaric oxygen （HBO） preconditioning on activation of plasma protein C in a rat model of asphyxial cardiac arrest-resuscitation. Methods A total of 105 adult male Sprague-Dawley rats, aged 70-90 days, weighing 260-320 g, were randomly divided into 3 groups： cardiac arrest group （group CA, n= 5） , cardiac arrest-resuscitation group （group CA/R, n = 50）, and hyperbaric oxygen preconditioning group （group H, n = 50）. Cardiac arrest was induced by campling the endotracheal tube at the end of expiration. The animals underwent HBO preconditioning once a day for 3 consecutive days before cardiac arrest was induced in group H. The rats were placed in the HBO chamber, 10 min later the pressure was increased at a constant rate until the hyperbaric oxygen reached 2 atmosphere absolute, and maintained at this level for 45 min, after the oxygen concentration〉95%, and then the pressure was decreased at a constant rate （within 20 rain） until the normal pressure was reached. The rats underwent no resuscitation in group CA. Five rats were selected from CA/R and H groups at 3, 6, 12 and 24 h after restoration of spontaneous circulation, and at 30 min of cardiac arrest in group CA, and blood samples were taken from the abdominal aorta for determination of the plasma activated protein C （APC） concentrations. The time from asphyxia to cardiac arrest, time for spontaneous regular cardiac rhythm, and successful resuscitation were recorded. Results Compared with group CA, the plasma APC concentrations were significantly decreased at each time point after restoration of spontaneous circulation in CA/R and H groups （P〈0.05）. Compared with group CA/R, the time from asphyxia to cardiac arrest was significantly prolonged, the time for spontaneous regular cardiac rhythm was shortened, the success rate of resuscitation was increased, and the plasma APC concentrations were increased at each time point after restoration of spontaneous circulation in group H （P 〈 0.05）. Conclusion HBO preconditioning can promote activation of plasma protein C after resuscitation in a rat model of asphyxial cardiac arrest, and is helpful in improving hypercoagulation.