蒙药安神补心六味丸预防给药对心肌缺血大鼠的保护作用及氧化应激水平的影响＊

目的 研究蒙药安神补心六味丸对大鼠心肌缺血损伤的保护作用和氧化应激机制。方法 将60只大鼠随机分为空白组、模型组、阳性对照组（丹参滴丸）及蒙药安神补心六味丸低、中、高剂量组，使用腹腔注射异丙肾上腺素方法制备大鼠急性心肌缺血模型，记录并观察大鼠心电图活动变化，然后进行腹主动脉取血，分离血清，测定乳酸脱氢酶（Lactic dehydrogenase，LDH）、肌酸激酶（Creatine kinase，CK）、磷酸肌酸激酶（Creatine kinase isoenzyme，CK-MB）、谷草转氨酶（Aspartate aminotransferase，AST）、超氧化物歧化酶（Superoxide dismutase，SOD）、丙二醛（Malondialdehyde，MDA）和谷胱甘肽过氧化物酶（Glutathione peroxidase，GSH-PX）含量变化。取心肌组织固定，对大鼠心肌组织进行HE染色，通过对心肌酶学和和心肌组织形态学两个方面来考察蒙药安神补心六味丸对大鼠心肌缺血模型的保护作用。结果 与空白组比较，模型组大鼠血清中LDH活性极显著升高（P<0.01），CK、CK-MB、AST、MDA活性均显著升高（P<0.05），SOD活性显著降低（P<0.05），GSH-PX活性高度显著降低（P<0.001），且差异均具有统计学意义；与模型组比较，蒙药安神补心六味丸组高剂量组大鼠血清中LDH、CK、CK-MB、MDA活性显著降低（P<0.05），SOD活性显著升高（P<0.05），GSH-PX活性极显著升高（P<0.01），且差异均具有统计学意义。从HE染色分析，蒙药安神补心六味丸能够改善因缺血而造成的心肌组织损伤。结论 蒙药安神补心六味丸能有效改善心肌组织病理状态，减轻大鼠心肌缺血损伤，以达到保护心肌作用，机制可能与氧化应激机制相关。     

Adrenergic β receptor activation reduces amyloid β1-42-mediated intracellular Zn2+ toxicity in dentate granule cells followed by rescuing impairment of dentate gyrus LTP

Adrenergic β receptor activation prevents human soluble amyloid β (Aβ)-induced impairment of long-term potentiation (LTP) in slices. On the basis of the evidence that human Aβ_1–42-induced impairment of LTP is due to Aβ_1–42-mediated Zn²⁺ toxicity, we postulated that adrenergic β receptor activation reduces Aβ_1–42-mediated intracellular Zn²⁺ toxicity followed by rescuing Aβ_1–42 toxicity. To test the effect of adrenergic β receptor activation, LTP was recorded at perforant pathway-dentate granule cell synapses of anesthetized rats 60 min after Aβ_1–42 injection into the dentate granule cell layer. Human Aβ_1–42-induced impairment of LTP was rescued by co-injection of isoproterenol, an adrenergic β receptor agonist, but not by co-injection of phenylephrine, an adrenergic α₁ receptor agonist. Isoproterenol did not reduce Aβ_1–42 uptake into dentate granule cells, but reduced increase in intracellular Zn²⁺ in dentate granule cells induced by Aβ_1–42. In contrast, phenylephrine did not reduce both Aβ_1–42 uptake and increase in intracellular Zn²⁺ by Aβ_1–42. In the case of human Aβ₁₋₄₀ and rat Aβ_1–42, which do not increase intracellular Zn²⁺, human Aβ₁₋₄₀- and rat Aβ_1–42-induced impairments of LTP were not rescued by co-injection of isoproterenol. The present study indicates that adrenergic β receptor activation reduces Aβ_1–42-mediated increase in intracellular Zn²⁺ in dentate granule cells, resulting in rescuing Aβ_1–42-induced impairment of LTP. It is likely that noradrenergic neuron activation by stimulating the locus coeruleus is effective for rescuing Aβ_1–42-induced cognitive decline that is caused by intracellular Zn²⁺ dysregulation in the hippocampus.     

异丙肾上腺素在经皮微球囊压迫三叉神经术中的效果

目的探讨异丙肾上腺素在三叉神经痛经皮微球囊压迫(percutaneous microballoon compression,PMC)中的效果。方法选择2016年5月至2017年12月连续收治的三叉神经痛行PMC的患者45例,男25例,女20例,年龄47~70岁,ASAⅠ或Ⅱ级,采用计算机随机数字表法随机分为两组:研究组(n=23)插管后5min泵注0.9%异丙肾上腺素0.6μg·kg~(-1)·h~(-1)使HR增快至80次/分后开始手术穿刺;对照组(n=22)在HR慢于60次/分时给予阿托品0.5mg静注。记录患者麻醉前(T0)、插管后5min(T_1)、穿刺开始时(T_2)、球囊压迫半月神经节时(T_3)、解除球囊压迫后5min时(T4)的SBP、DBP和HR。计算两组患者SBP、DBP、HR在T_2、T_3时差值的绝对值,分别记为△SBP、△DBP、△HR。记录术中窦性停搏和高血压的发生情况。结果 T0、T_1时两组SBP、DBP、HR差异无统计学意义。T_2、T_3时研究组HR明显快于对照组(P0.05)。研究组△SBP、△DBP明显小于对照组(P0.05)。对照组术中有2例窦性停博。研究组术中高血压发生率明显低于对照组[8(34.8%)vs 14(63.4%),P0.05]。结论 PMC术中使用异丙肾上腺素泵注,与使用阿托品比较,患者BP变化幅度更小,HR增快的幅度更大,为球囊压迫时的HR骤降提供了更加安全的范围。     

野生山葡萄多酚对异丙肾上腺素诱发的小鼠心肌缺血的保护作用

目的评价野生山葡萄多酚(PVAS)对异丙肾上腺素诱发的小鼠心肌缺血的保护作用。方法采用皮下注射异丙肾上腺素(ISO)建立小鼠急性心肌缺血模型,观察不同剂量PVAS对模型小鼠ECGⅡ导联异常ST段,心肌含水量(MWC),心肌指数(M I)及血清磷酸肌酸激酶(CK)和乳酸脱氢酶(LDH)的影响。结果400 mg/kg PVAS可显著改善ISO诱发小鼠异常ECGⅡ导联ST段抬高,抑制MWC、M I的升高并降低血清CK、LDH水平(P<0.05)。结论PVAS对小鼠急性心肌缺血损伤具有保护作用。     

Luteolin promotes mitochondrial protection during acute and chronic periods of isoproterenol induced myocardial infarction in rats

ObjectiveAn attempt has been made to evaluate the mitochondrial protection in acute and chronic periods after isoproterenol (ISO)-induced myocardial-infarction (MI) in male Wistar rats.Materials and methodsLuteolin was supplemented by intra-gastric intubation at a daily dose of 0.3 mg/kg body weight for 30 days. In the acute MI model, luteolin had been administered once per day to rat groups during 30 days. On 29th and 30th days, the rats of the acute MI control groups were administered 85 mg/kg body weight, isoproterenol, intra-peritoneally at an interval of 24 h. In the chronic MI model luteolin was supplemented to the rat group during 30 days. On the 1st and 2nd days, the rats of the chronic MI control and luteolin treatment groups were administered ISO by the same way.ResultsThe isoproterenol-treated rats both in acute and chronic models showed an increase in the level of TBARS and a decrease in the activities of mitochondrial antioxidants in MI rats, an increase in levels of mitochondrial lipid profile except phospholipids and the activities of mitochondrial enzymes were decreased in isoproterenol-treated rats. Oral treatments with luteolin in both acute and chronic models showed a significant decrease in the levels of mitochondrial lipid peroxidation, increase in the mitochondrial antioxidant levels and also decrease in the mitochondrial enzymes.ConclusionThus the present study revealed that luteolin ameliorates mitochondrial damage in isoproterenol induced myocardial infarction by maintaining lipid peroxidation metabolism due to its free radical scavenging, mitochondrial lipids, antioxidants and mitochondrial enzymes. Histopathological observations were also in correlation with the biochemical parameters.     

Increased Basic Fibroblast Growth Factor (bFGF) Accumulation and Distinct Patterns of Localization in Isoproterenol-Induced Cardiomyocyte Injury

Basic FGF is a multifunctional protein which promotes regeneration in several tissues. To investigate involvement in cardiac injury-repair, bFGF accumulation and localization was examined in hearts of rats injected with a single high dose of isoproterenol. The bFGF content of cardiac extracts was analyzed at 6 and 24 hours as well as 1, 4, and 6 weeks by western blotting of heparin-sepharose-bound fractions. The 18 kilodalton bFGF species showed an approximately 2-fold increase in extracts from treated animals compared to non-treated controls. A transient rise in a 21–23 kilodalton bFGF species was seen at 24 hours after treatment. An induction of bFGF mRNA was also observed in treated animals. To localize bFGF in vivo, immunofluorescent labelling with specific antibodies was used at 4–24 hours and 1–4 weeks after treatment. Simultaneous labelling for the cytoskeletal proteins vinculin or vimentin was employed to identify viable myocytes or non-muscle interstitial cells, respectively. Necrotic myocytes, identified by loss of vinculin, displayed a pronounced increase in cytoplasmic anti-bFGF staining compared to adjacent normal myocytes. This increase occurred prior to and may play a role in promoting mobile cell migration and proliferation in areas of necrosis. Viable cardiomyocytes adjacent to fibrotic regions displayed strong pericellular anti-bFGF staining and, occasionally, were also stained by anti-vimentin antibodies, suggesting reexpression of an embryonic phenotype and thus an attempt for regeneration. These data showing increased accumulation and distinct patterns of localization of bFGF in the hearts of isoproterenol-treated animals suggest that this growth factor plays a role in short-term as well as long term response of the myocardium to injury.     

Cardioprotective effects of cerebrolysin on the lesion severity and inflammatory factors in a rat model of isoproterenol-induced myocardial injury

BackgroundMyocardial injury (MI) is an important heart condition and a major cause of morbidity and mortality worldwide. The current study was designed to investigate the cardioprotective effects of cerebrolysin (CLY) on the lesion severity and inflammatory factors in male rats using isoproterenol (ISO)-induced MI model.MethodsMI in rats was induced by injecting ISO (100 mg/kg) subcutaneously (sc) on the first 2 days. Then, CLY (5 ml/kg) was injected intraperitoneally (ip) post-treatment for 7 days. On the 3rd day, creatine phosphokinase (CK-MB) and cardiac troponin I (cTnI) levels in serum and, on the 10th day, the TNF-α and IL6 levels in serum and heart tissue were measured by enzyme-linked immunosorbent assay (ELISA). Finally, the heart of each rat was dissected out and stained for histopathological examination.ResultsOn the 3rd day, the serum CK-MB and cTnI levels in the ISO and CLY + ISO groups were significantly increased compared with that in the control and CLY + Sal groups. One week after the induction of MI, ISO administration showed a significant increase in the serum level of TNF-α in the ISO group compared with that in the control and CLY + Sal groups. Also, our findings showed only a moderate reduction in inflammatory cell infiltration and extent of edema following CLY treatment in the CLY + ISO group. Also, CLY induced vascular proliferation in the heart tissue.ConclusionsWe conclude that the severity of pathological changes induced by ISO in MI (e.g. inflammation and edema) can be limited by CLY treatment.     

滁菊总黄酮对异丙肾上腺素致大鼠急性心肌缺血的影响

目的 观察滁菊总黄酮对异丙肾上腺素（ISO）致急性心肌缺血模型大鼠的保护作用。方法 将大鼠皮下注射ISO复制大急性心肌缺血模型,观察滁菊总黄酮对模型大鼠心电,血清肌酸激酶（CK）、乳酸脱氢酶（LDH）、心肌组织超氧物歧化酶（SOD）、过氧化氢酶（CAT）和丙二醛（MDA）含量的影响。结果 滁菊总黄酮能够抑制急性心肌缺血模型大鼠心电图J点抬高,降低血清CK、LDH活性,升高心肌组织SOD、CAT活性,降低MDA含量。结论 滁菊总黄酮对ISO致心肌缺血模型大鼠有保护作用。     

Increased cardiac myosin ATPase activity as a biochemical adaptation to running training: enhanced response to catecholamines and a role for myosin phosphorylation

The effects were studied of prior running training on protein phosphorylation and adenosine triphosphatase (ATPase) activities of natural actomyosin isolated from perfused rat hearts. Myosin Ca²⁺-ATPase activities were significantly higher in running-trained hearts than in controls, whereas the Ca²⁺-stimulated, Mg²⁺-dependent ATPase activities of natural actomyosin were not changed. After treatment of isolated perfused hearts with the β-agonist isoproterenol, both troponin-I and myosin P light chains became phosphorylated. Troponin-I phosphorylation (1 mol/mol) was the same in both sets of hearts and was accompanied by similar changes in cardiac cyclic AMP contents. The V_max values for myosin Ca²⁺-ATPase activity were increased after isoproterenol treatment in all the perfused hearts, but to a significantly greater extent in the hearts of running trained animals; this was correlated with enhancement of both the rate and extent of myosin P light chain phosphorylation. Enhanced Ca²⁺-dependent myosin P light chain phosphorylation, further enhanced by β-adrenergic stimulation, represents, at the molecular level, a biochemical response to running training.