Lin Yujia, Song Bin, Lin Qingming, Qian Xin, Chen Hongyi, Wang Xiaoping, Lin Shirong
Provincial Clinical Medical College, Fujian Medical University, Fuzhou 350001, Fujian, China.
Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350122, Fujian, China.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2021 Sep;33(9):1099-1104. doi: 10.3760/cma.j.cn121430-20210528-00791.
To explore the protective effects of bradykinin postconditioning on cardiopulmonary resuscitation (CPR) rats, and to assess the underlying mechanisms.
Forty-eight adult male Sprague-Dawley (SD) rats were randomly divided into four groups according to random number table: Sham operation group, cardiac arrest (CA) group, bradykinin treatment (BK) group, and AMP-activated protein kinase (AMPK) inhibitor Compound C+ bradykinin treatment (CP+BK) group, finally, 8 rats in each group were taken for follow-up experiment. CA was induced by asphyxia. Rats in the Sham group received arteriovenous catheterization, endotracheal intubation, and mechanical ventilation, without CA. Compound C (250 μg/kg) was intraperitoneally injected in CP+BK group 30 minutes before CA, and the same volume of dimethyl sulfoxide (DMSO) was given in the remaining groups. Bradykinin (150 μg/kg) was intraperitoneally injected in BK group and CP+BK group 48 hours after restoration of spontaneous circulation (ROSC), and same volume of saline was given in the remaining groups. The neural function of rats in each group was evaluated with neurological deficit score (NDS) 72 hours after ROSC. Microtubule-associated protein light chain 3 (LC3) and p62 expressions were detected by immunohistochemistry, autophagosomes were observed by transmission electron microscopy, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method (TUNEL) assay was used to assess apoptosis.
Compared with the Sham group, the NDS was decreased (60.75±5.80 vs. 80.00±0.00, P < 0.01), the expression levels of LC3 and p62 elevated [LC3 (A value): 1.04±0.64 vs. 0.40±0.14, p62 (A value): 2.75±0.57 vs. 0.36±0.12, both P < 0.05], the number of autophagosomes and apoptotic cells increased in the CA group [(39.00±8.00)% vs. (3.87±1.90)%, P < 0.05]. Compared with the CA group, the NDS (67.75±6.32 vs. 60.75±5.80, P < 0.05), the expression of LC3 (A value: 1.60±0.34 vs. 1.04±0.64, P < 0.05), and the number of autophagosomes increased in the BK group, while the expression of p62 and the rate of apoptotic cells reduced [p62 (A value): 1.51±0.32 vs. 2.75±0.57, apoptotic cells rate: (23.03±1.91)% vs. (39.00±8.00)%, both P < 0.05]. Compared with the BK group, the NDS (59.00±8.19 vs. 67.75±6.32, P < 0.05), the expression of LC3 (A value: 0.62±0.41 vs. 1.60±0.34, P < 0.05) and the number of autophagosomes declined in the CP+BK group, while the expression of p62 and the rate of apoptotic cells elevated [p62 (A value): 3.50±0.47 vs. 1.51±0.32, apoptotic cells rate: (44.53±10.15)% vs. (23.03±1.91)%, both P < 0.05].
Bradykinin postconditioning played a neuroprotective role in CPR rats by activating autophagy and reducing apoptosis.
探讨缓激肽后处理对心肺复苏（CPR）大鼠的保护作用，并评估其潜在机制。
48只成年雄性Sprague-Dawley（SD）大鼠按随机数字表随机分为四组：假手术组、心脏骤停（CA）组、缓激肽处理（BK）组和AMP激活蛋白激酶（AMPK）抑制剂Compound C+缓激肽处理（CP+BK）组，每组最终选取8只大鼠进行后续实验。采用窒息法诱导CA。假手术组大鼠进行动静脉插管、气管插管及机械通气，但不进行CA。CP+BK组在CA前30分钟腹腔注射Compound C（250μg/kg），其余组给予相同体积的二甲基亚砜（DMSO）。自主循环恢复（ROSC）后48小时，BK组和CP+BK组腹腔注射缓激肽（150μg/kg），其余组给予相同体积的生理盐水。ROSC后72小时，用神经功能缺损评分（NDS）评估各组大鼠的神经功能。采用免疫组织化学法检测微管相关蛋白轻链3（LC3）和p62表达，透射电子显微镜观察自噬体，采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）检测细胞凋亡。
与假手术组相比，CA组NDS降低（60.75±5.80比80.00±0.00，P<0.01）；LC3和p62表达水平升高[LC3（A值）：1.04±0.64比0.40±0.14，p62（A值）：2.75±0.57比0.36±0.12，均P<0.05]；自噬体数量和凋亡细胞数量增加[（39.00±8.00）%比（3.87±1.90）%，P<0.05]。与CA组相比，BK组NDS（67.75±6.32比60.75±5.80，P<0.05）、LC3表达（A值：1.60±0.34比1.04±0.64，P<0.05）及自噬体数量增加，而p62表达和凋亡细胞率降低[p62（A值）：1.51±0.32比2.75±0.57，凋亡细胞率：（23.03±1.91）%比（39.00±8.00）%，均P<0.05]。与BK组相比，CP+BK组NDS（59.00±8.19比67.75±6.32，P<0.05）、LC3表达（A值：0.
