地塞米松诱导金属硫蛋白表达对大鼠缺血/再灌注损伤心肌的保护作用研究

目的 探讨地塞米松诱导金属硫蛋白(MT)表达对大鼠缺血/再灌注(I/R)损伤心肌的延迟保护作用.方法 将32只SD大鼠随机分成地塞米松组和对照组,分别予腹腔注射地塞米松和蒸馏水预处理.预处理24 h后构建Langendorff离体心脏I/R动物模型,缺血30 min后再灌注60 min.用蛋白质免疫印迹法(Western blotting)检测MT表达;动态观测缺血前及再灌注期间血流动力学指标[左心室发展压(LVDP)、左室内压上升和下降最大速率(±dp/dt max)、冠状动脉循环流出量(CF)]、心律失常的变化;测定心肌梗死面积、冠状动脉流出液肌酸激酶同工酶(CK-MB)漏出率、心肌丙二醛(MDA)、总超氧化物歧化酶(T-SOD)、铜锌-SOD(CuZn-SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化酶(GSH-Px)水平及心肌细胞膜Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性.结果 与对照组比较,地塞米松组MT的表达水平显著增加(3.085±1.065比1.028±0.016,P＜0.05);再灌注期间LVDP、±dp/dt max及CF均得到明显改善(P均＜0.05);再灌注性室性心律失常评分明显减少[(2.00±1.41)分比(6.63±4.24)分,P＜0.05];心肌梗死面积明显缩小[(28.38±11.22)%比(47.39±8.30)%,P＜0.01];冠状动脉流出液CK-MB的漏出率明显降低[(8.69±4.16)U/g比(18.15±5.59)U/g,P＜0.01];心肌组织MDA含量降低(P＜0.05),T-SOD、CuZn-SOD、CAT、GSH-Px均明显升高(P＜0.05或P＜0.01);心肌细胞膜的Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性增加(P＜0.01和P＜0.05).结论 地塞米松可能通过上调MT的表达,对大鼠I/R损伤心肌起到延迟保护作用.     

Serum creatine kinase isoenzyme MB concentration after endomyocardial biopsy

Serum total creatine kinase (CK), CK-MB and myoglobin (Mb) were serially determined in 17 patients who underwent endomyocardial biopsy. Mean total CK levels increased from 36 +/- 27 U/l 30 min before biopsy to a maximum of 112 +/- 77 U/l 8 h following the procedure (p less than 0.05). Similarly, Mb concentrations rose from 57 +/- 55 micrograms/l to 119 +/- 57 micrograms/l 30 min after biopsy (p less than 0.05). Normalization of total CK and Mb levels occurred within 16 and 8 h, respectively. A new immunoenzymetric assay (IEMA) was used to measure the mass concentration of the CK-MB molecule. The initial CK-MB levels were 0.2 +/- 0.4 microgram/l; a small but significant elevation was recorded as early as 2 h after biopsy (1.6 +/- 1.5 micrograms/l, p less than 0.05). CK-MB returned to initial concentration 16 h after the beginning of the procedure. Comparison with the maximum CK-MB levels recorded in 16 myocardial infarction patients (258 +/- 172 micrograms/l, range 90-680 micrograms/l) indicated that the modest increase of CK-MB level detected after biopsy probably reflects a limited endomyocardium lesion at the sampling site, excluding any significant myocardial damage. Total CK and Mb, which showed more pronounced elevations than CK-MB, are likely to originate from other sources than the myocardium.     

Mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in sera of patients after myocardial infarction

Mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase (AST) were studied in the sera of 42 patients following acute myocardial infarction and compared to creatine kinase (CK), lactate dehydrogenase (LDH) and alanine aminotransferase (ALT). Mitochondrial AST( ASTm ) was detected in 93% (39/42) of patients. Maximum recorded ASTm activity was 59.5 +/- 8.8 U/l and was found 39.4 +/- 3.5 hours after the onset of symptoms (chest pain) of myocardial infarction. In contrast the maximum recorded cytoplasmic AST ( ASTc ) activity was greater (327 +/- 23 U/l) and it occurred earlier (33.5 +/- 2.2 hours) after onset of infarction compared to ASTm . ASTm correlated significantly (p less than 0.05) with ASTc , LDH and ALT but not with total CK or CK-MB. ASTc correlated significantly (p less than 0.05) with total CK, CK-MB and LDH but not ALT. Maximum recorded ASTm activity was significantly associated with the clinical assessment of left ventricular failure ( Killip classification) but not with ventricular arrhythmias. In a subset of 15 patients evaluated with invasive hemodynamic measurements of cardiac output and pulmonary capillary wedge pressure. ASTm correlated significantly (p less than 0.05) and better than CK-MB with the hemodynamic assessment of left ventricular dysfunction. Thus ASTSm can be readily identified in sera of patients after acute myocardial infarction and may be of value in the evaluation of patients with acute myocardial infarction.     

心肌梗死前心绞痛对合并糖尿病急性前壁心肌梗死患者左心室舒张功能的影响

目的 探讨心肌梗死前心绞痛对合并糖尿病的急性前壁心肌梗死患者左心室舒张功能的影响.方法 行急诊冠状动脉造影示梗死相关动脉为前降支近中段病变并成功进行经皮冠状动脉介入治疗(PCI)的首次急性前壁心肌梗死患者114例,其中63例合并有糖尿病,共分为4组;非糖尿病心肌梗死前有心绞痛组23例(A组);非糖尿痛心肌梗死前无心绞痛组28例(B组);糖尿痛心肌梗死前有心绞痛组28例(C组);糖尿病心肌梗死前无心绞痛组35例(D组).比较心肌梗各组死前心绞痛对肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)峰值浓度和左心室舒张功能的影响.结果 CK、CK-MB的峰值浓度A组显著低于B组,CK(1 696±1 062)U/L vs(2 988±1 632)U/L,CK-MB(125±83)U/L vs(236±159)UIL(P<0.05或<0.01),二尖瓣口舒张早期血流峰值流速(PE)/舒张晚期血流峰值流速(PA):A组显著高于B组和C组,1.07±0.38 vs 0.87±0.26、0.78±0.23(P<0.05或<0.01),而C组与D组之间这些指标差异均无统计学意义(P>0.05).结论 心肌梗死前心绞痛不能改善合并糖尿病急性前壁心肌梗死患者的左心室舒张功能.     

缺血预适应在合并急性前壁心肌梗死的糖尿病患者中的临床研究

目的探讨缺血预适应(ischemic preconditioning,IP)对合并急性前壁心肌梗死的糖尿病患者梗死面积和左室功能的近期影响。方法114例行急诊冠状动脉造影示梗死相关动脉为前降支近段病变并进行成功经皮冠状动脉成形术(PCI)术的首次急性前壁心肌梗死患者,其中有63例合并有糖尿病,分组比较IP对肌酸激酶(CK)及肌酸激酶同工酶(CK-MB)峰值浓度和左室功能的影响。共分为4组:非糖尿病IP组23例(A组);非糖尿病非IP组28例(B组);糖尿病IP组28例(C组);糖尿病非IP组(D组)35例。结果CK、CK-MB的峰值浓度A组显著低于B组(P<0.01),左室射血分数值A组显著高于B组(P<0.01)。C组与D组比较各项指标差异均无统计学意义(均P>0.05)。结论IP在无糖尿病的急性前壁心肌梗死患者中可能有助于限制梗死面积,保护左室功能,而在合并糖尿病的急性前壁心肌梗死患者中,未观察到上述心脏保护作用。     

促红细胞生成素用于急性心肌梗死的临床观察

目的 探讨重组型促红细胞生成素(rh-EPO)对改善急性心肌梗死(AMI)患者心功能的作用.方法48例符合诊断标准、接受静脉溶栓治疗且溶检成功的首次AMI患者随机分为两组,治疗组在溶栓后即给予rh-EPO 2000 U/次,每周3次,共治疗4周.期间测定肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)峰值浓度,采用Hindmen修正的12导联QRs积分系统估算梗死面积(S),第4周末测定左心室舒张末内径(LVEDd)和左心室射血分数(LVEF),并与对照组比较,同时观察rh-EPO治疗期间不良反应的发生情况.结果治疗组反映梗死严重程度的CK、CK-MB和梗死面积均较对照组明显减轻,差异有统计学意义(均P<0.05);在rh-EPO治疗4周后,反映心功能的LVEDd和LVEF在治疗组也有改善趋势,但两组差异无统计学意义.结论 rh-EPO治疗AMI能有效保护缺血和梗死心肌,明显减轻梗死程度,并可在一定程度上改善心功能.     

Clinical predictors of myocardial damage after high voltage electrical injury

Myocardial damage after high voltage electrical body injury is a serious and often life-threatening situation. The purpose of this pilot study was to identify early clinical predictors of myocardial damage in patients with high voltage electrical injury. Twenty-four patients with high voltage electrical injuries and no evidence of arc burns were evaluated. In 13/24 patients the diagnosis of myocardial damage was confirmed by total creatine kinase (CK) and creatine kinase MB (CK-MB) isoenzyme elevation (group A). In these patients the total CK range was 1373 to 52,544 mU/ml. In 11/24 patients CK-MB was negative (group B) indicating absence of myocardial damage. ECG changes occurred in 10/13 group A and 4/11 group B patients (p less than .095). No patient in either group gave a history suggestive of myocardial ischemia after the electrical injury. The pathways of electricity through the body, as mapped by a line drawn between the wound(s) of entrance and exit, were vertical in all group A patients, i.e., from upper to lower body segment, vs. 5/11 group B patients with evidence of a vertical pathway (p less than .003). Group A patients also had greater body surface burns (16.0 +/- 2.7%) vs. group B patients (4.0 +/- 1.6%, p less than .001). The presence of a vertical pathway and the magnitude of percent surface burns were found to be the most significant clinical predictors of myocardial damage in multiple logistic regression analysis (p less than .0001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Creatine kinase MB and M-mode echocardiographic changes in cardiac contusion

Cardiac contusion was suspected in 95 patients with severe blunt chest trauma of whom 93 did not require hospitalization. Creatine kinase (CK) MB isoenzyme activity was elevated over 4.0 U/l in 10 (10.5%) patients (CK MB positive) by between 2% and 8% (mean +/- SE 4.1 +/- 0.6%), when the total CK was 296 +/- 74 (mean +/- SE). Two patients had a pericardial rub. M-mode echocardiography was performed on 16 patients: 7 CK MB positive (CK MB+) and 9 CK MB negative (CK MB-) without the physician's knowledge of the CK MB status of the patients. The left ventricular end-diastolic diameter, in healthy subjects 48.3 +/- 4.9 mm, was increased to 55.4 +/- 1.8 mm (p less than 0.01) in CK MB+ patients and to 56.3 +/- 6.0 mm (p less than 0.01) in CK MB- patients. The end-systolic left ventricular diameter, in healthy subjects 36.7 +/- 5.2 mm, was increased to 42.4 +/- 6.7 mm (p less than 0.01) in CK MB+ patients and to 41.3 +/- 6.5 mm (p less than 0.01) in CK MB- patients. The mean ejection fraction was 48.6 +/- 11.0 in CK MB+ and 53.6 +/- 11.8 in CK MB- group. Minor contractile abnormalities occurred in all CK MB+ patients in 2 or more left ventricular regions and in 7 out of 9 CK MB- patients in 1 or 2 regions. The regional motion pattern was hypokinesia with sharp systolic deflections at abnormal areas and hyperkinesia on normal segments. Aortic root was enlarged in all patients with contusion and CK MB+. There was no apparent increase in left atrial size. "Flattened" ST-segment and T-waves were seen in 5 CK MB+ patients but not in the CK MB- patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum creatine kinase and CK-MB isoenzyme responses to acute and prolonged swimming in trained athletes

Six highly-trained male swimmers completed a maximum work capacity tethered swim and a 1-h continuous tethered swim at approximately 70% VO2max in order to evaluate total serum creatine kinase and CK-MB isoenzyme changes. Venous blood obtained before, 5 min post-, 6 h post-, and 24 h post-exercise was analyzed for total serum CK (kinetic UV method, normal = less than 100 U/l) and CK-MB isoenzyme (quantitative electrophoretic technique, normal = less than 5 U/l). VO2max averaged 4.59 +/- 0.28 l/min, with a mean total work time of 24.5 min to achieve maximum capacity. Mean resting total CK was 100.5 +/- 15.8 U/l. Compared to rest, neither swim bout produced a significant (p greater than 0.05) elevation in mean total creatine kinase. No CK-MB isoenzyme was observed in any post-exercise blood sample. Swimming, performed by highly-trained swimmers at high levels of intensity or for prolonged durations, may not impose sufficient degrees of trauma producing muscular stress. Therefore, the structural integrity of the cell membrane is maintained and the loss of intracellular creatine kinase to the bloodstream prevented.     

The ischemia-modified albumin in relation to pacemaker and defibrillator implantation

BACKGROUND: Ischemia-modified albumin (IMA) is considered a marker of myocardial ischemia whereas cardiac enzymes are released when cardiac necrosis occurs. It has previously been shown that permanent pacemaker-defibrillator insertion is associated with myocardial injury expressed as cardiac enzyme rise. OBJECTIVE: We assessed whether pacemaker-defibrillator implantation also induces changes in IMA plasma levels and whether, therefore, myocardial ischemia precedes necrosis. METHODS: We studied 64 consecutive patients undergoing pacemaker or defibrillator implantation; 43 were men and 21 women and their age was 70 +/- 11 years (range 23-84 years). Blood samples were collected at baseline, six hours and 48 hours following the procedure. IMA measured by the albumin cobalt binding test (ACB, Integra 800 analyzer), as well as creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB) and cardiac troponin I (Tn-I) were evaluated. RESULTS: Data analysis showed that compared to baseline measurements, IMA increased at six hours (P = 0.015) and at 48 hours (P = 0.003)[97.6 +/- 10.2 vs 101.4 +/- 10.7 vs 102.1 +/- 9.2 U/mL at baseline, six hours and 48 hours, respectively]; similarly, CK increased at six hours (P = 0.0001) and remained high at 48 hours (P = 0.0001) [74.9 +/- 49.9 vs 136.1+/-186.7 vs 115.2 +/- 63.9 mIU/mL], while CK-MB increased at six hours (P = 0.0001), but returned to baseline values at 48 hours (P = 0.05) [0.90 +/- 0.89 vs 1.27 +/- 134 vs 0.71 +/- 0.63 ng/mL] and Tn-I increased at six hours (P = 0.0001) and returned to baseline levels at 48 hours (P = 0.32) [0.057 +/- 0.23 vs 0.16 +/- 0.36 vs 0.03 +/- 0.045 ng/mL]. CONCLUSION: Permanent pacemaker-defibrillator insertion is associated with myocardial ischemia and necrosis.     

血清心肌肌钙蛋白-I、肌酸激酶同工酶对新生儿缺氧缺血性脑病心肌损伤的诊断价值

目的 探讨血清心肌肌钙蛋白I（CTn-I）、肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）及CK-MB／CK对新生儿缺氧缺血性脑病（HIE）患儿心肌损伤的诊断价值。方法 对2001年8月至2003年12月78例HIE患儿与对照组同期入住新生儿病房26例无缺氧性脑痛的患儿于出生后18～24h取血，分别用快速固相免疫层析法、NAC-免疫抑制法、NAC法测定血清CTn-I、CK、CK-MB并计算CK-MB／CK值。结果 对照组、轻、中、重HIE四组患者间血清CTn-I、CK、CK-MB有显著性差异（P〈0．05）。其中3例重度HIE伴阵发性室性心动过速，CTn-I〉125ng／L；而CK-MB虽有升高，但无明显差异；CK-MB／CK值在各组中无明显差异。结论 重视对HIE患儿心脏功能的监测与治疗，对改善患儿的预后具有非常重要的意义，在评价HIE患儿心肌损伤时，CTn-I是比CK-MB及CK更敏感、更具有特异性的指标，所以CK-MB／CK不宜作为HIE患儿心肌损伤的生化指标。     

高位脊髓损伤对大鼠心肌功能的影响

目的 探讨高位脊髓损伤(SCI)对大鼠心肌的影响以及内皮素-1(ET-1)在其中的作用。方法 采用Allens打击法制备中度高位SCI动物模型。大鼠随机分为假手术对照组以及C7损伤后4、12、24、48和 72 h 6组(n=8).记录各组平均动脉压(MAP)、心率(HR)、左室收缩峰压(LVSP)和左室内压变化最大速率 (±dp／dt max);测定各组血清乳酸脱氢酶(LDH)、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)和ET-1的含 量变化;取心肌组织匀浆,测定心肌组织ET-1含量变化。另取心肌内壁组织作透射电镜扫描,观察心肌超微 结构的变化。结果 各损伤组的HR、MAP、LVSP及±dp／dt max均显著下降(P<0.05或P<0.01).尤以伤 后12 h下降最显著(P均<0.01);而3种心肌酶均显著升高(P<0.05或P<0.01)。血浆和心肌ET-1在损 伤后4 h即明显升高(P均<0.05),12 h达高峰。高位SCI 12 h后,大鼠心肌肌丝轻度溶解,线粒体空泡变性。 结论 高位SCI后大鼠心肌受到一定程度损害,全身和心肌局部ET-1产生过多可能是参与因素之一。     

肌酸激酶同工酶质量判定肌病心肌损害的局限性

目的 通过对比小儿心肌炎、肌病时血清中肌酸激酶同工酶(CK-MB)质量与肌钙蛋白I(cTnI)和肌红蛋白(Mb)的动态变化,观察CK-MB质量在判定心肌损伤中的意义.方法 测定40例心肌炎患儿(其中有20例为暴发性心肌炎)和38例肌病患儿的肌酸激酶(CK)、CK-MB活性、CK-MB质量、cTnI、Mb、心电图以及脉冲多普勒超声心动图;肌病组同时进行肌电图、遗传代谢病筛查以及基因检测.以同期本院发育儿科门诊除外甲状腺功能减低症的10例身矮待查儿童为对照.结果 ①健康对照组儿童CK(U/L)为95.0±27.0,CK-MB活性(U/L)为22.6±1.3,CK-MB质量(μg/L)为2.4±0.3,cTnI(μg/L)为0.012±0.001.②心肌炎组患儿治疗前CK(1 033.0±408.0)、CK-MB活性(101.2±31.5)、CK-MB质量(38.2±13.2)、cTnI(5.544±1.554)均较健康对照组明显升高(均P＜0.01);随着治疗时间延长,各项指标逐渐下降;治疗2周后CK(59.3±25.1)、CK-MB活性(24.6±13.2)、CK-MB质量(3.3±2.9)、cTnI(0.125±0.128)均恢复至正常水平(均P＞0.05).治疗1周后CK、CK-MB质量增高率即较治疗前明显下降[CK:5.9％(1/17)比56.4％(22/39);CK-MB质量:8.3％(1/12)比61.1％(22/36),均P＜0.01],CK-MB质量恢复先于cTnI,增高率出现明显差异[8.3％(1/12)比73.7％(14/19),P＜0.05].③肌病组治疗前CK(10 193.0±1 447.0)、CK-MB活性(311.7±44.4)以及CK-MB质量(229.2±47.9)均较健康对照组明显升高(均P＜0.01),但cTnI不高(0.021±0.002);治疗2周后CK(5 735.6±6 187.8)、CK-MB活性(170.7±143.0)、CK-MB质量(207.4±136.6)仍维持在高水平,cTnI(0.230±0.150)则维持在正常水平;各项指标的增高率与治疗前均无显著差异[CK:85.7％(6/7)比97.4％(37/38); CK-MB活性:85.7％(6/7)比97.4％(37/38);CK-MB质量:100.0％(2/2)比94.1％(32/34);cTnI:0(0/1)比6.4％(2/31),均P＞0.05].结论 ①在心肌炎时,CK-MB质量与cTnI一致,急性期升高,恢复期降至正常,但CK-MB质量观察窗短于cTnI.②在肌病时,CK-MB质量与cTnI 分离,前者治疗前后均升高,后者正常,故用测定CK-MB质量来判定肌病患儿是否有心肌损害意义有限.     

急性心肌梗死患者血浆N-末端脑钠肽前体水平检测及其临床意义

目的探讨急性心肌梗死(AMI)患者住院早期血浆N-末端脑钠肽前体(NT-proBNP)水平与梗死面积、心功能及住院期心脏事件的关系。方法采用ELISA法测定41例AMI患者住院后48小时内血浆NT-proBNP水平,并与患者肌酸激酶(CK)和肌酸激酶同功酶(CK-MB)峰值浓度、左室射血分数(LVEF)、住院期主要不良心脏事件(MACE)对比分析。结果AMI患者血浆NT-proBNP水平明显高于正常对照组(699.44±386.28pg/ml vs 41.75±24.26pg/ml,P<0.001)。血浆NT-proBNP水平与CK、CK-MB峰值浓度呈正相关(r=0.817,P=0.001;r=0.772,P=0.001),与LVEF呈负相关(r=-0.661,P<0.01)。住院期发生MACE患者的血浆NT-proBNP水平明显高于未发生MACE者(971.50±367.01pg/ml vs 393.60±261.16pg/ml,P<0.001)。结论AMI患者血浆NT-proBNP水平与CK、CK-MB峰值呈正相关,与LVEF呈负相关。检测血浆NT-proBNP水平可预测AMI患者梗塞面积、心功能及住院期心血管事件。     

血液停跳液对冠状动脉旁路移植术患者围术期心肌酶的影响

目的:了解血液停跳液对心肌在术中缺血再灌注损伤影响的程度和手术后恢复的情况,为临床治疗提供依据.方法:39例冠状动脉旁路移植术(CABG)患者术前1 d,术后1、3、5、8 d晨分别取静脉血,测定血清谷草转氨酶(AST)、磷酸肌酸激酶及同功酶MB(CK、CK-MB),乳酸脱氢酶及同功酶1(LDH、LDH-1).结果:择期手术的CABG患者术前5种心肌酶均在正常范围,术后1 d分别升高到术前的3～15倍(P＜0.01);术后3 d均有不同程度的恢复,CK-MB已恢复到正常范围,其他4种酶仍显著高于术前水平(P＜0.05或P＜0.01);术后5 d继续恢复,LDH和LDH-1仍高于术前水平(P＜0.01),CK也恢复到正常水平,AST虽仍略高于正常水平,但是其与术前测定值相比差异无显著性(P＞0.05或P＜0.01);术后8 d LDH与LDH-1仍未恢复正常(P＜0.05).结论:血液停跳液对CABG患者可以提供满意的心肌保护.择期手术的CABG患者术前5种心肌酶均在正常范围;这些心肌酶的释放术后1 d达最高峰,CK-MB恢复最快,CK与AST次之,LDH和LDH-1最慢,术后8 d仍明显高于术前水平;要判断心肌损伤的恢复应以LDH和LDH-1的恢复为标准.     

肌酸激酶及其同工酶、肌红蛋白等在电烧伤患者中的应用

目的探讨肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）、α-羟丁酸脱氢酶（HBDH）及心肌肌钙蛋白I（cTnI）、肌红蛋白（Myo）在电烧伤患者中的应用。方法检测电烧伤患者（包括电击伤和电弧伤）的CK、CK．MB、HBDH的含量及cTnI与Myo的阳性率，并与急性冠状动脉综合征（ACS）患者和健康对照组进行比对分析。结果电烧伤患者的CK、CK-MB、HBDH的含量及cTnI与Myo的阳性率均显著高于健康对照组（P〈0．01）；电烧伤患者的CK、CK-MB和Myo的阳性率明显高于ACS组（P〈0．01），HBDH的测定值与ACS组比较差异无统计学意义（P〉0．05），而cTnI的阳性率则低于ACS组。电击伤组Myo的阳性率明显高于电弧伤组（P〈0．01）。讨论CK、CK-MB、HBDH水平及Myo阳性率的增高可能是触电导致肌肉损伤引起的，与心脏损伤不一定有关。cTnI可用于判定电烧伤患者是否出现心脏损害。     

Dynamics of creatine kinase shuttle enzymes in the human heart

Myocardial cytoplasmic creatine kinase subunits M and B, mitochondrial CK (CKMIT), and citrate synthase (CS) were determined in 10 locations of the normal human heart (n = 8) and in papillary muscles of patients operated on for mitral regurgitation (n = 6). Compared to atrial biopsies, septal and left ventricular biopsies showed higher activities for CS (P less than 0.0001), total CK (P less than 0.05) and CKMIT (P less than 0.0001). CKM was evenly distributed. CKB activity in the right septum and left ventricular locations were 0.5-1% of total CK and 4-5 times lower than those of the atria and the right ventricular free wall. Activities of CS, CKB and CKMIT in right septal biopsies did not differ from those in left ventricular locations. The activities of CS, total CK, and CKM in papillary muscle from patients operated on for mitral regurgitation did not differ from that of healthy papillary muscle. CKMIT was about 40% lower (P less than 0.02), whereas CKB was 15-20 times higher (P less than 0.0001) than in the healthy heart. In conclusion, adaptations within the creatine kinase system occur in the human heart in health and disease. Small amounts of CKB in the normal left ventricle, as opposed to the right ventricular free wall, might be related to differences in myocardial perfusion during the cardiac cycle. In disease, a decreased CKMIT and dramatically increased CKB may indicate a stressed intracellular energy transfer. CK enzyme activities in right septal biopsy specimens may be used as an indication of metabolic stress on the myocardium of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)     

The value of serum CK-MB and myoglobin measurements for assessing perioperative myocardial infarction after cardiac surgery

In 41 patients who underwent coronary bypass surgery, creatine kinase (CK)-MB mass concentration was repeatedly measured in serum during and after the intervention using a new two-site immunoenzymetric assay (IEMA). Serum CK-MB activity was determined with the use of four different techniques: immunoinhibition, immunoinhibition-immunoprecipitation, column chromatography and electrophoresis. Myoglobin (Mb) was also measured in each specimen by radioimmunoassay. In the 33 patients who followed a completely uneventful postoperative course, the cumulated CK-MB release was, on the average, 12.2-fold less than after acute myocardial infarction. The CK-MB peak concentrations using the IEMA were 33 +/- 3 micrograms/l (X +/- SEM) and occurred 6.4 +/- 0.5 h after the intervention was started; CK-MB levels had decreased to 2.9 +/- 0.4 micrograms/l at the end of the first postoperative day. The evolution of the CK-MB concentration was parallel to that of the enzyme activity. The serum Mb maximum concentrations (518 +/- 39 micrograms/l) were reached after 3.3 +/- 0.1 h. The other eight patients developed perioperative myocardial infarction (PMI); in this group, the cumulated CK-MB release was higher, and the serum CK-MB postoperative curves were of three different types. The patients with delayed CK-MB peaks (type I pattern) or sustained elevations (type III) of this isoenzyme also showed increased serum Mb levels at the end of the first postoperative day. The PMI patients with early (10 h) CK-MB elevations (type II) did not demonstrate abnormal serum Mb levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

强力霉素预处理减轻在体大鼠心肌缺血/再灌注损伤及基质金属蛋白酶-1/9的表达

目的 观察强力霉素预处理对在体大鼠心肌缺血/再灌注(I/R)损伤时基质金属蛋白酶-1(MMP-1)和MMP-9表达的影响.方法 64只体重300～350 g的健康雄性SD大鼠被随机分为假手术组(n=16)、I/R组(n=24)和强力霉素预处理组(n=24).分别观察在体大鼠心肌缺血60 min再灌注120 min后的心肌I/R损伤,以及强力霉素预处理对其心功能、血浆肌酸激酶(CK)和乳酸脱氢酶(LDH)水平及心肌组织髓过氧化物酶(MPO)活性的影响;以免疫组化法检测心肌细胞MMP-1和MMP-9的蛋白表达.结果 心肌再灌注120 min时,I/R组左室收缩压(LVSP)、左室压最大上升和下降速率(±dp/dtmax)均较假手术组显著下降,左室舒张末压(LVEDP)、血浆CK和LDH以及心肌组织MPO活性均显著升高,且MMP-1和MMP-9的蛋白表达明显增强(P＜0.05或P＜0.01).而强力霉素预处理组心功能各项指标以及血浆CK、LDH均明显改善,MMP-1和MMP-9的蛋白表达均明显受抑,与I/R组比较差异均有统计学意义(P＜0.05或P＜0.01).结论 强力霉素预处理在减轻在体大鼠心肌I/R损伤的同时,还可抑制MMP-1和MMP-9的蛋白表达.     

Human myocardial and skeletal muscle enzyme activities: creatine kinase and its isozyme MB as related to citrate synthase and muscle fibre types

Summary. Activities of myocardial and skeletal muscle total creatine kinase (CK) and its isozyme MB were related to the oxidative capacity [measured as the citrate synthase (CS) activity] and to the contractile characteristics (estimated as the percentage of type I muscle fibres). Skeletal muscle biopsies were obtained both from physically trained and untrained men and myocardial biopsies from patients subjected to open-heart surgery performed because of mitral or aortic valve disease. Enzyme activities were determined on freeze-dried muscle specimens. The CK-MB activity was about twice as high in trained skeletal muscle as in untrained ones reaching the myocardial level. The total CK activity was about three times higher in skeletal muscle than in myocardium; the myocardium, however, had CS activity 3–4 times larger than that of skeletal muscle. A close correlation was demonstrated between activities of CK-MB on one hand and CS (r= 0·76) or percentage type I fibres (r= 0·83) on the other hand suggesting a connection between CK-MB activity and the oxidative capacity of the cell. This was in contrast to total CK where different regressions were obtained when comparing the myocardium and the skeletal muscle of trained or untrained men. In conclusion, CK-MB activity in trained skeletal muscle in athletes were similar to that in myocardium. CK-MB was related to the oxidative capacity and formation of cellular energy in skeletal and heart muscle.