消退素D1对猪心肺复苏后心功能障碍的影响及机制研究

The effects of resolvin D1 on myocardial dysfunction after cardiopuimonary resuscitation in swine and its potential mechanisms

目的 制作猪心肺复苏模型，探讨消退素D1改善复苏后心功能障碍的效果及可能机制。方法 国产健康雄性白猪28头，体重（36±3）kg。采用电刺激法诱发室颤8 min，心肺复苏5 min，制备心肺复苏猪模型。动物采用随机数字表法分为4组（n=7）：假手术组（S组）、心肺复苏组（CPR组）、低剂量消退素D1组（LRD组）和高剂量消退素D1组（HRD组）。S组仅进行动物准备，不经历心脏骤停/复苏过程。复苏后5 min时，LRD组、HRD组分别静脉注射消退素D1 0.3 μg/kg、0.6 μg/kg，另两组注射等量溶媒。复苏后3 h、6 h和24 h时，应用PiCCO监测仪评估每搏输出量（SV）和全心射血分数（GEF）的变化，同时采集静脉血标本检测血清心肌肌钙蛋白（cTNI）的浓度。复苏后24 h时处死猪，取心肌组织，检测肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、丙二醛（MDA）的含量和超氧化物歧化酶（SOD）的活性。结果 与S组相比，其他三组动物在心肺复苏后均出现心功能障碍，表现为SV与GEF值明显降低、血清cTNI浓度显著增加（均P〈0.05）。与CPR组相比，LRD组和HRD组SV与GEF值明显升高、cTNI浓度显著减少，组间比较差异均有统计学意义（均P〈0.05）。与LRD组相比，HRD组心功能指标与血清标志物水平进一步明显改善（均P〈0.05）。组织分析显示，心肺复苏后动物均存在心肌炎症反应和氧化应激损伤，表现为心肌TNF-α、IL-6与MDA含量增加，SOD活性降低。与CPR组相比，LRD组和HRD组心肌TNF-α、IL-6与MDA含量明显减少，SOD活性显著升高，组间比较差异均有统计学意义（均P〈0.05）。HRD组心肌炎症与氧化应激指标较LRD组进一步改善（均P〈0.05）。结论 消退素D1能改善猪心肺复苏后心功能障碍，且呈剂量依赖性，其机制可能与减轻炎症和氧化应激有关。

Objective To establish a porcine model of cardiopulmonary resuscitation to explore the effectiveness of resolvin D1 in improving post-resuscitation myocardial dysfunction and its potential mechanisms. Methods Twenty-eight male domestic pigs weighing 36±3 kg were utilized. The pig model was established by 8 mins of untreated ventricular fibrillation and then 5 mins of cardiopulmonary resuscitation. The animals were randomly divided into 4 groups （n =7 each） ： sham operation group （group S）, cardiopulmonary resuscitation group （group CPR）, low-dose resolvin D1 group （group LRD）, and high-dose resolvin D1 group （group HRD）. The animals in group S only got the general preparation without the procedure of cardiac arrest and resuscitation. At 5 min after resuscitation, the doses of resolvin D1 0. 3μg/kg and 0. 6μg/kg were respectively injected via the femoral vein of pigs in LRD and HRD groups, and meanwhile the equal volume of vehicle was given into the animals in the other two groups. At 3 h, 6 h and 24 h after resuscitation, the changes of stroke volume （SV） and global ejection fraction （GEF） were evaluated by a PiCCO monitor, and meanwhile the concentration of cardiac troponin I （cTNI） in serum was measured. At 24 h after resuscitation, the pigs were sacrificed, and myocardial tissue was obtained for the determination of tumor necrosis factor - alpha （ TNF - α）, interleukin - 6 （ IL - 6 ）, malondialdehyde （MDA）, and superoxide dismutase （SOD） activity. Results Compared with group S, significantly decreased SV and GEF and markedly increased concentration of serum cTNI were observed in the other three groups with post - resuscitation myocardial dysfunction （ all P 〈 O. 05 ）. Compared with group CPR, the values of SV and GEF were significantly increased while the concentration of serum cTNI was significantly decreased in LRD and HRD groups [SV （ml） ： 28±5, 31±5 vs. 23±4 at3 hrs, 32±3, 36 ±6 vs. 27±6 at 6 hrs, 35 ±5, 41 ±5 vs. 29±5 at 24 hrs; GEF （%） ： 17±2, 19±2 vs. 14±1 at 3 hrs, 20±2, 23±3 vs. 16±3 at6hrs, 23±2, 26±3 vs. 20 ±2at24hrs; cTNI（pg/ml）：247±34,230±26vs. 324± 56 at 3 hrs, 553 ±37, 501±34 vs. 611±44 at 6 hrs, 436 ±23,371 ±29 vs. 553±47 at 24 hrs, all P〈 0. 05 ]. Compared with group LRD, myocardial function and serum markers were further significantly improved in group HRD （ all P 〈 O. 05 ）. The inflammation and oxidative stress in myocardial tissue were observed in all the animals experiencing cardiac arrest and resuscitation, which were indicated by increased levels of TNF-α, IL- 6 and MDA and decreased SOD activity. Compared with group CPR, the levels of TNF-α, IL- 6 and MDA were significantly decreased while SOD activity was significantly increased in LRD and HRD groups [TNF-α （pg/ml） ： 442±87, 218±55 vs. 653±112; IL -6 （pg/ml） ： 563±68,403±61 vs. 824±117; MDA （nmol/mg）： 3. 95±0. 96,2. 54±1. 21vs. 6. 37±1. 26; SOD （U/mg） ： 2. 27±0. 93, 3. 36±0. 74 vs. 0. 89±0. 31, all P〈0. 05]. The morbidity of myocardial inflammation and oxidative stress were further significantly ameliorated in group HRD evidenced by the figure of biomarkers compared with group LRD （ all P 〈 O. 05 ）. Conchltsions Resolvin D1 can improve post - resuscitation myocardial dysfunction in a dose - dependent manner in swine, and the mechanism is related to the inhibition of inflammation and oxidative stress.