Minocycline postconditioning protects myocardium from ischemia-reperfusion injury through attenuating poly(ADP-ribose) polymerase excessive activation

AIM: To investigate whether minocycline postconditioning protects rat myocardium from ischemia-reperfusion (I/R) injury through attenuating poly(ADP-ribose)polymerase-1(PARP-1) excessive activation. METHODS: The left anterior descending coronary artery was ligated for 45 min and then reopened for 2 h to establish the rat model of myocardial ischemia-reperfusion injury. The male Wistar rats (n=90) were randomly divided into sham group, I/R group, low-and high-dose minocycline groups, and 3-aminobenzamide (3-AB, PARP inhibitor) group. The myocardial infarct size was measured by Evans blue and 2,3,5-triphenyltetrazolium chloride (TTC) staining. The morphological changes of the myocardium were observed with HE staining. The cardiomyocyte apoptosis was detected using in situ TDT-mediated dUTP nick end labeling (TUNEL). The level of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in the serum were measured by ELISA. The content of poly(ADP-ribose) (PAR) in the reperfused myocardium and peripheral leukocytes were detected by Western blot. RESULTS: Compared with sham group, PAR expression, TNF-α content and IL-1β concentration increased in all other groups. Compared with I/R group, treatment with low and high doses of minocycline and 3-AB significantly reduced the infarct size and myocardial apoptosis. PAR expression, TNF-α content and IL-1β concentration in low-and high-dose minocycline groups and 3-AB group all decreased. No significant difference of the above parameters between high-dose minocycline group and 3-AB group was observed. CONCLUSION: Minocycline postconditioning may attenuate myocardial ischemia-reperfusion injury by depressing the activation of PARP-1 in cardiomyocytes and peripheral leukocytes in rats.     

Influence Of Allopurinol On The Pathophysiology Of Experimental Gastric Dilatation-Volvulus

Gastric dilatation-volvulus (GDV) was surgiclly induced in 10 dogs. Five of the dogs were pretreated with 50 mg/kg PO of allopurinol to determine the effect of xanthine oxidase inhibition on the pathophysiology of GDV. After 150 minutes, the GDV was corrected, and lactated Ringer's solution was administered intravenoulsy (resuscitation). Two hundred forty minutes after relief fo GDV, the dogs were euthanatized without recovery from anesthesia. Administration of allopurinol was associated with a reduced (P<0.01) incidence of hepatic necrosis and a lower (P<0.045) serum phosphorus level than observed in the control group at the end of the experiment. The increase in base deficit in the allopurinol-treated group after resuscitation was also less(P<0.045) than the control group. In conclusion, this study suggests that inhibition of xanthine oxidase-derived oxygen free radicals protects against hepatic necrosis in dogs with GDV. Resuscitation appears to be a time of profound physiologic stress for dogs with GDV.     

Protective effect of gabexate mesilate on blood-brain barrier in rats with cerebral ischemia-reperfusion

AIM To investigate the protective effects of gabexate mesilate （GM） on blood-brain barrier （BBB） permeability in rat model with cerebral ischemia-reperfusion （I/R）. METHODS Adult male SD rats （n=180） were randomly divided into sham group, I/R group, nimodipine （NMP; 2 mg·kg^-1·d^-1） group and GM （5, 10 and 20 mg·kg^-1·d^-1） groups （n=30 in each group）. The rat model of cerebral I/R was established by blocking the middle cerebral artery with thread plug for 2 h. Ten min before modeling, the drugs were given intraperitoneally. The nerve function was detected by Longa scoring method. The permeability of BBB was measured by Evans blue permeation method, and the brain water content was measured by dry-wet weight method. The activity of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px）, and the content of malondialdehyde （MDA） in brain tissue were determined by biochemical analysis. The content of tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β） and IL-6 was measured by ELISA. The mRNA expression of matrix metalloproteinase-2 （MMP-2）, MMP-9 and nuclear factor-κB （NF-κB） was detected by RT-PCR. The protein levels of MMP-2, MMP-9 and NF-κB were determined by Western blot. RESULTS Compared with I/R group, the Longa score, permeability of Evans blue and brain water content of the rats in GM （10 and 20 mg·kg^-1·d^-1） and NMP （2 mg·kg^-1·d^-1） groups were decreased. The activity of SOD and GSH-Px was increased, while the content of MDA was decreased. The content of TNF-α, IL-1β and IL-6 was decreased, and the mRNA and protein expression levels of MMP-2, MMP-9 and NF-κB were significantly down-regulated. Compared with NMP （2 mg·kg^-1·d^-1） group, the Longa score and permeability of Evans blue were decreased in GM （20 mg·kg^-1·d^-1） group, the activity of SOD was increased, and the content of MDA and TNF-α was decreased. The mRNA and protein expression levels of MMP-2, MMP-9 and NF-κB were down-regulated. All of the differences were significant （P<0.05 or P<0.01）. CONCLUSION GM has protective effect on BBB in the rats with cerebral I/R. Its mechanism may be related to inhibition of oxidative stress and inflammation, and down-regulation of MMP-2, MMP-9 and NF-κB expression.     

基于网络药理学研究丹参-川芎抗脑缺血再灌注损伤作用机制及试验验证

【目的】 通过网络药理学研究丹参-川芎药对治疗缺血性脑卒中的有效性成分及相应基因靶标，探讨其作用机制。【方法】 应用中药系统药理学计数平台（TCMSP）、GeneCards、OMIM数据库，筛选出丹参-川芎药对治疗缺血性脑卒中的潜在靶点并进行GO功能和KEGG通路富集分析。分别设置假手术组、模型组、丹参-川芎低、中、高剂量组，采用预防和治疗给药方式对线栓制备的脑缺血再灌注模型大鼠进行干预，采用Zea-longa评分法对脑缺血再灌注24 h模型大鼠进行神经功能评分，苏木素-伊红（HE）染色法观察脑组织病理学变化进行初步验证。【结果】 本研究共筛选到丹参-川芎药对主要有效活性成分共72个，其中川芎7个，丹参65个，缺血性脑卒中的靶点基因1 972个，有效活性成分与缺血性脑卒中共同作用靶标94个，包括IL6、IL10、TNF、MMP9、VEGFA、CASP3等；GO功能和KEGG通路富集结果提示，丹参-川芎药对治疗缺血性脑卒中与PI3K-Akt、cGMP-PKG、VEGF等多个信号通路有关。动物试验结果表明，丹参-川芎可减轻脑组织病理改变，减轻神经功能缺损，改善脑缺血再灌注损伤。【结论】 丹参-川芎药对可能是通过PI3K/Akt信号通路改善脑缺血再灌注损伤，发挥抗细胞凋亡的作用。