Cardioprotective effects of sinomenine in myocardial ischemia/reperfusion injury in a rat model

BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.     

乌司他丁对严重烧伤患者伤后早期心肌损害的防治作用

目的观察乌司他丁（UTI）对烧伤“休克心”的防治作用，探讨其可能的机制。方法选择笔者单位收治的伤后24h内入院、烧伤面积〉50％TBsA的34例特重度烧伤患者，分为烧伤组和UTI治疗组，每组17例。两组患者均进行常规治疗，且UTI治疗组患者入院后立即给予UTI10万U静脉滴注，3次／d，连续7d。于两组患者伤后2、4、7d采血，检测其血浆中性粒细胞弹性蛋白酶（PMN elastase）、心肌肌钙蛋白I（cTnI）含量和心肌型肌酸激酶同工酶（CK—MB）活性，以公认的各指标正常值作参考，并对3项指标进行相关性分析。结果（1）伤后2、4、7d，两组患者血浆PMN elastase及cTnI含量均显著高于正常值（P〈0．01）；UTI治疗组与烧伤组比较，两指标偏低。（2）与正常值比较，伤后2、4、7d烧伤组患者CK—MB活性明显升高（P〈0．01），第4天达高峰；UTI治疗组伤后2、4d CK—MB活性明显高于正常值（P〈0．05或0．01），但与烧伤组比较升幅较小，第7天降至正常值水平（P〉0．05）。（3）34例烧伤患者PMN elastase、cTnI含量及CK—MB活性三者间均呈现显著正相关，前两者的相关系数为0．904，后两者的相关系数为0．922，PMN elastase含量与CK-MB活性的相关系数为0．829（均为P〈0．01）。结论UTI能够显著减轻严重烧伤患者心肌损害的程度，有效抑制PMN elastase的过度释放。     

内皮素与P-选择素在冠心病中的意义

目的：研究内皮素（ET－1）、P－选择素、肌钙蛋白I（CTn1)在急性心肌梗死（AMI）和不稳定性心绞痛（UA）中的意义，方法：用放射免疫法测ET－1，流式细胞术测定P－选择素，Access化学发光测CTn1，共检测23例AMI患、21例UA患及28例健康对照。结果：AMI组的ET－1、P－选择素、CTn1值均显高于对照组（P＜0．05－0．005）；UA组的ET－1、P－选择素显高于对照组（P＜0．05）；UA组的CTn1与对照组差异无显性（P＞0．05）；UA组的P－选择素、CTn1显低于AMI组（P＜0．05）。多元回归分析发现P－选择与CTn1相关，相关系数r=0.404，P＜0．01。结论：ET－1、P－选择素是检测血栓前状态的敏感指标。     

非心脏手术围术期心肌酶谱和肌钙蛋白Ⅰ的变化

目的 观察非心脏手术围术期心肌酶谱和肌钙蛋白Ⅰ(cTnI)的释放规律.方法 30例年龄≥60岁择期全麻手术患者,分别在术前、术中、术毕即刻、术后第1天和第2天测定心肌酶谱,包括谷草转氨酶(AST)、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)、肌红蛋白(Myo)、α-羟丁氨酸转氨酶(α-HBDH)、线粒体谷草转氨酶(m-AST)和cTnI的值,同时监测HR、BP和ECG.结果 cTnI在非心脏手术围术期未发生心肌缺血或心肌梗死的病例中无显著变化,而心肌酶谱则在术毕和术后第1天均有显著升高(P＜0.05或P＜0.01)或超出参考值上限.结论 心肌酶谱在非心脏手术围术期变化显著;cTnI受非心脏手术和麻醉影响较小.     

急性心肌梗死静脉溶栓后cTnT浓度比值对判断冠脉再通的价值

目的　探讨血清心肌肌钙蛋白T(cTnT) 3h 2h的浓度比值对急性心肌梗死 (AMI)溶栓后判定冠状动脉再通的价值。方法　采用ELISA法动态检测了 5 7例接受尿激酶静脉溶栓治疗的AMI患者和 31例正常健康对照血清cTnT ,CK MB及CK水平 ,并计算溶栓后 3h与 2h血清cTnT浓度比值。结果　①cTnT释放呈现两种特征 ,再通组呈双峰型 ,未通组呈单峰型 ,且再通组后期峰值较未通组峰值低 (P <0 .0 1)。②cTnT浓度 3h 2h比值再通组明显高于未通组 (P <0 .0 1) ,以该比值 >1.4 8作为判定再通的标准 ,其对判定冠状动脉再通的敏感性、特异性、预测值分别为 83.3% ,90 .5 % ,93.8%。与峰值时间判定冠脉再通比较差异无显著性 (P >0 .0 5 )。结论　cTnT的动态检测可有效地判定对AMI溶栓后再通与否 ,特别是溶栓后 3h 2h浓度比值 >1.4 8可作为早期判定冠脉再通的标准 ,且具有迅速、省时等优点 ,值得推广应用     

Effects of marathon running on running economy and kinematics

The present study was designed to investigate interactions between running economy and mechanics before, during, and after an individually run marathon. Seven experienced triathletes performed a 5-min submaximal running test on a treadmill at an individual constant marathon speed. Heart rate was monitored and the expired respiratory gas was analyzed. Blood samples were drawn to analyze serum creatine kinase activity (S-CK), skeletal troponin I (sTnI), and blood lactate (B-La). A video analysis was performed (200 frames · s⁻¹) to investigate running mechanics. A kinematic arm was used to determine the external work of each subject. The results of the present study demonstrate that after the marathon, a standardized 5-min submaximal running test resulted in an increase in oxygen consumption, ventilation, and heart rate (P < 0.05), with a simultaneous decrease in the oxygen difference (%) between inspired and expired air, and respiratory exchange ratio (P < 0.05). B-La did not change during the marathon, while sTnI and S-CK values increased (P < 0.05), peaking 2 h and 2 days after the marathon, respectively. With regard to the running kinematics, a minor increase in stride frequency and a similar decrease in stride length were observed (P < 0.01). These results demonstrate clearly that weakened running economy cannot be explained by changes in running mechanics. Therefore, it is suggested that the increased physiological loading is due to several mechanisms: increased utilization of fat as an energy substrate, increased demands of body temperature regulation, and possible muscle damage. Accepted: 20 March 2000     

Recombinant troponin I substitution and calcium responsiveness in skinned cardiac muscle

Using treatment with vanadate solutions, we extracted native cardiac troponin I and troponin C (cTnI and cTnC) from skinned fibers of porcine right ventricles. These proteins were replaced by exogenously supplied TnI and TnC isoforms, thereby restoring Ca²⁺-dependent regulation. Force then depended on the negative logarithm of Ca²⁺ concentration (pCa) in a sigmoidal manner, the pCa for 50% force development, pCa₅₀, being about 5.5. For reconstitution we used fast-twitch rabbit skeletal muscle TnI and TnC (sTnI and sTnC), bovine cTnI and cTnC or recombinant sTnIs that were altered by site-directed mutagenesis. Incubation with TnI inhibited isometric tension in TnI-extracted fibers in the absence of Ca²⁺, but restoration of Ca²⁺ dependence required incubation with both TnI and TnC. Relaxation at low Ca²⁺ levels and the steepness of the force/pCa relation depended on the concentration of exogenously supplied TnI in the reconstitution solution (range 20–150 μM), while Ca²⁺ sensitivity, i.e. the pCa₅₀, was dependent on the isoform, and also on the concentration of TnC in the reconstitution solution. At pH 6.7, skinned fibers reconstituted with optimal concentrations of sTnC and sTnI (120 μM and 150 μM, respectively) were more sensitive to Ca²⁺ than those reconstituted with cTnC and cTnI (difference in pCa₅₀ approx. 0.2 units). Rabbit sTnI was cloned and expressed in Escherichia coli using a high yield expression plasmid. We introduced point mutations into the TnI inhibitory region comprising the sequence of the minimal common TnC/actin binding site (-G¹⁰⁴-K-F-K-R-P-P-L-R-R-V-R¹¹⁵-). The four mutants produced by substitution of T for P¹¹⁰, G for P¹¹⁰, G for L¹¹¹, and G for K¹⁰⁵ were chosen, based on previous work with synthetic peptides showing that single amino acid substitution in this region diminished the capacity of these peptides to inhibit acto-S₁ ATPase or contraction of skinned fibers. Therefore, all amino acid residues of the inhibitory region are thought to contribute to biological activity of TnI. However, each of the recombinant TnIs could substitute for endogenous TnI. In combination with exogenous TnC, Ca²⁺ dependence could be restored when ^gly110sTnI, ^thr110sTnI or ^gly111sTnI was used for reconstitution. The mutant ^gly105sTnI, on the other hand, reduced the ability of skinned fibers to relax at low Ca²⁺ concentrations and it caused an increase in Ca²⁺ sensitivity. Received: 5 October 1995/Received after revision and accepted: 1 December 1995     

严重挤压伤大鼠早期心脏损伤的某些发病机制的探讨

目的:观察挤压伤大鼠血浆心钠素(ANP)、内皮素-1(ET-1),血清心肌肌钙蛋白I(cTnI)浓度的改变,阐明心钠素、内皮素与心脏损伤的关系。方法:复制挤压伤大鼠动物模型,全自动生化分析仪检测血清心肌酶改变,放射免疫法检测血浆ANP,ET-1水平,化学发光法检测血清cTnI浓度。结果:挤压伤后12 h,血浆ET-1显著低于对照组,血浆ANP、血清心肌酶、cTnI水平显著高于对照组,并持续48 h以上。结论:肢体挤压伤早期存在心肌细胞的损伤,其损伤可能与ANP、ET-1有重要关系。     

Associated changes in Ca2+ and Sr2+ activation properties and fiber proteins in cross-reinnervated rabbit soleus

Changes in the Ca²⁺ and Sr²⁺ activation properties of functionally skinned slow-twitch soleus fibers were measured and compared with those of normal fast-twitch extensor digitorum longus (EDL) following cross-reinnervation of soleus with the nerve to EDL. Most of the fibers showed either complete transformation of activation properties (66%) or remained unchanged (34%). The change in sensitivity to divalent cations was correlated with changes in the proteins present in fibers pooled on the basis of their activation properties. The banding patterns of the 35,000- and 37,500-dalton proteins (tropomyosin and troponin T) in cross-reinnervated soleus were correspondingly transformed to those of normal EDL. Slow and fast myosin light chains were present in the pooled cross-reinnervated fibers. Fiber distributions based on activation properties were confirmed by histochemical features. For the first time it has been demonstrated that cross-reinnervation produced changes in the activation properties of soleus fibers and associated changes in the regulatory proteins measured.     

血清Troponin I, CK-MBmass, Myoglobin在急性心肌梗塞诊断中的应用评价

为了解CTnI,CK-MBmass 和Mb指标对急性心肌梗塞(AMI)早期诊断、后期监测及预后判断的临床意义,采用微粒子化学发光法,对20例AMI患者、24例不稳定心绞痛(UA)患者、17例骨骼肌损伤(SM)患者和19例健康者(对照组)进行血清CTnI,CK-MBmass 和Mb的测定,并对AMI患者胸痛发生3～5小时,8～14小时,20～24小时,72小时和7天共五个时段进行了测定.结果:AMI患者发病早期CTnI,CK-MBmass 和Mb的阳性检出率分别为65%,70%,70%,CTnI在UA患者组和SM患者组中未检出.CTnI,CK-MBmass 和Mb测定值含量在AMI组中明显高于UA组和SM组,AMI患者组CTnI分别是UA组和SM组的84倍和91.63倍,CK-Mbmass分别是该二组的8.82倍和4.67倍, Mb分别是该二组的11.57倍和2.25倍,AMI组与UA组和SM组比较,有显著性差异(P＜0.001).AMI患者组中该三项指标的动态测定显示,在疾病发生早期(3～5小时)时,CTnI,CK-MBmass 和Mb都有显著性升高,随时间延长而逐渐升高,高峰值期均在8～14小时段,72 小时时Mb已基本回到正常.7天时血清中仍有CTnI的持续存在,但CK-MBmass已接近正常.以上显示,CTnI ,CK-MBmass 和Mb在早期诊断AMI时,都具有较高的敏感性,CTnI在AMI患者中的阳性检出率具有心肌特异性.CK-MBmass 和Mb在诊断心肌损伤时也具有较高的临床价值.但CTnI具有最长的窗口时间,在选择用于AMI的后期监护和愈后判断指标时,CTnI应是最佳的首选指标.