Activities of key enzymes in the energy metabolism of human myocardial and skeletal muscle

Activities of total creatine kinase (CK), its isoenzyme MB (CK-MB), total lactate dehydrogenase (LD) and its isoenzyme LD1, phosphofructokinase (PFK), aspartate aminotransferase (ASAT) and citrate synthase (CS) were determined in skeletal muscle biopsies obtained from physically trained and untrained men and in myocardial biopsies from patients subjected to open heart surgery because of valve disease. The LD1, ASAT and CS activities were higher in trained than in untrained skeletal muscle and still higher in heart muscle than in either trained or untrained skeletal muscle. The CK-MB activity was higher in trained than untrained skeletal muscle and the myocardial CK-MB activity was similar to that in trained skeletal muscle. Total CK activity was slightly lower in trained than in untrained skeletal muscle and the myocardial CK activity was approximately one third of the skeletal muscle CK. Both the PFK and the total LD activity was of similar magnitude in the different muscle types. In conclusion, as estimated by enzyme activities, the oxidative capacity is 2-3 times larger in myocardial than in skeletal muscle, while the glycolytic capacity as estimated by PFK appears to be the same.     

甲状腺功能异常患者心肌酶变化的分析

为了解原发性甲状腺功能减退症（甲减）患者和甲状腺功能亢进（甲亢）患者心肌酶的变化,检测了20例原发性甲减患者、27例甲亢患者以及30例健康体检者（对照组）的空腹血清天门冬酸氨基转移酶（AST）、肌酸激酶（CK）及其同工酶（CK-MB）、乳酸脱氢酶（LDH）及其同工酶（HBDH）、FT3、FT4、TSH、总胆固醇（Tch）。结果显示,原发性甲减患者AST、CK、CK-MB、LDH、HBDH及Tch均明显高于对照组（P分别〈0.01、0.01、0.01、0.01、0.05、0.01）;TSH和FT4与心肌酶、Tch均无相关性;FT3与CK、CK-MB负相关（r=-0.53,-0.47,P均〈0.05）,与Tch呈负相关（r=-0.504,P〈0.05）;甲亢患者血清CK-MB明显高于对照组（P〈0.01）,且血清FT4与CK-MB呈显著正相关（r=0.462,P〈0.01）。结论：原发性甲减患者和甲亢患者常伴心肌酶升高,其中甲减者FT3水平与CK、CK-MB、Tch升高关系更密切。     

High creatine kinase MB concentration and activity in patients with rhabdomyosarcoma

A 14-year-old boy with rhabdomyosarcoma (RMS) of the left palm showed increased concentration and activity of creatine kinase (CK; EC 2.7.3.2) MB in his serum. CK isoenzyme analysis revealed no extra band. Other laboratory data including high lactate dehydrogenase (LD) isoenzyme 2, CK isoenzyme BB and MB, neuron specific enolase (NSE), and clinical findings did not support the diagnosis of myocardial infarction. The high activity and concentration of CK-MB in serum is possibly originated from the tumor. We could follow his time-course and analyze laboratory data of him and other 6 patients with RMS. We concluded that CK-MB, both concentration and activity, was the more sensitive marker of disease states of RMS than NSE and LD to follow up the patients with RMS.     

Optimization and evaluation of cardiac enzymes and isoenzymes measured on a random access analyzer

Four serum enzymes and isoenzymes used in the diagnosis of acute myocardial infarction (AMI), lactate dehydrogenase LD and LD-1, creatine kinase (CK), and CK-MB have been adapted to the Technicon RA-1000 automated clinical chemistry analyzer. Analytical parameters have been adjusted to provide clinically acceptable precision for all four assays. Correlations with centrifugal analyzer procedures gave correlation coefficients ranging from 0.998 to 0.999. A limited clinical study of the CK-MB assay indicated that a discriminant value of 13 U per L could separate AMI from non-AMI patients.     

小儿肺炎患者治疗前后心肌酶学指标的检测分析

目的:观察小儿肺炎患者心肌酶水平变化并分析其临床意义。方法:选择2009年8月～2011年8月住院治疗的小儿肺炎患者112例,其中重症组32例,轻症组80例,对照组为体检正常小儿68例。采用全自动生化分析仪检测各肺炎组治疗前后及对照组天冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)、肌酸激酶(CK)及其同工酶(CK-MB)活性水平,并进行组间比较。结果:与对照组相比,轻症组及重症组治疗前AST、LDH、CK、CK-MB水平均明显升高,其差异有统计学意义(P均<0.05),且重症组水平明显高于轻症组(P<0.05);治疗后,重症组及轻症组心肌酶水平均明显低于治疗前水平(P<0.05),且与对照组接近(P>0.05)。结论:小儿肺炎患者病情越重,心肌酶升高越明显,针对性治疗可使其恢复正常。     

Increase in myoglobin content and decrease in oxidative enzyme activities by leg muscle immobilization in man

Biopsies from m. quadriceps femoris from the operated leg of nine patients were taken before, and 6 weeks after, knee surgery. During the whole postoperative period the operated leg was immobilized with the knee in 40-50 degrees of flexion. Myoglobin (MYO) and the enzymes citrate synthase (CS), creatine kinase (CK) and its isozymes MB (CK-MB) and mitochondrial CK (CK-MIT), aspartate aminotransferase (ASAT), phosphofructokinase (PFK) and lactate dehydrogenase (LD) were determined on the biopsies. Citrate synthase, ASAT, CK, CK-MB, CK-MIT and LD activities were decreased (12-30%) after the postoperative leg immobilization period. Phosphofructokinase did not change, while MYO content was increased (16%). In conclusion, a different control of the synthesis of oxidative enzymes and MYO is suggested, as the induced changes following immobilization were in opposite directions. The function of the increased MYO content may be to facilitate the oxygen extraction.     

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

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.     

Evaluation of a protocol for lactate dehydrogenase (LD) isoenzymes

Two divergent laboratory approaches to the measurement of lactate dehydrogenase (LD) isoenzymes (LDIs) were evaluated. Abnormal values for total creatine kinase (CK), CK-MB, total LD, and LDIs were greater than 250 U/L, greater than or equal to 5% total CK, greater than 180 U/L, and LD1/LD2 ratio greater than 1.0, respectively. The first approach, measuring LDI on all requests regardless of total LD activity, showed the following results: 161 LDI specimens, 63 CK-MB + (LD1 greater than LD2, 6; LD1/LD2 normal, 57); 98 CK-MB - (LD1 greater than LD2, 5, LD1/LD2 normal, 93). Medical chart review of the 98 CK-MB negative specimens, representing 44 patients, showed that in seven patients with acute myocardial infarction (MI), none would have been missed clinically even if LDIs had not been done, and in only one case did LDIs play a confirmatory role in a patient who persistently had CK-MB-negative results but who had a strong clinical suspicion of MI. None of the 42 patient specimens with normal total LD activity had an LD1 greater than LD2. The second approach, measuring LDIs only if requested, only if total CK was abnormal, only if results for CK-MB were negative, and only if total LD was abnormal, showed the following results: 71 LDI specimens were not done (46 with normal total LD, 25 CK-MB + specimens). Medical chart review of the 71 LDIs not determined, representing 38 patients, showed that none of the 14 patients with the final diagnosis of MI would have been clinically missed, even if LDI had not been done, and in only one instance did LDIs confirm the clinical suspicion of MI in a patient with previously negative results for CK-MB. The LDI protocol represented by the second approach has been shown to be an effective means of identifying those occasional patients who require this confirmatory test, in whom the CK-MB results are negative but in whom there is a strong clinical suspicion of MI.     

Diagnostic enzyme profile in houbara bustard tissues (Chlamydotis undulata macqueenii)

We have reported tissue profiles of diagnostic enzymes in heart, liver, kidney, duodenum, pancreas, pectoral muscle and quadriceps muscle from houbara bustards (Chlamydotis undulata macqueenii). Enzymes studied included aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALKP), lactate dehydrogenase (LDH) and creatine kinase (CK). The data from our studies suggest that the tissue enzymes which are commonly used as clinical diagnostic tools in other species may also be used to evaluate tissue integrity in houbara bustards. However, although tissue enzyme patterns in the bustard showed some similarities compared with other avian species, there were also important differences. GGT and ALKP activities were predominantly present in the bustard kidney. CK appeared to be a sensitive indicator of muscle cell damage in the bustard. Although ALT, LDH and AST appeared to be sensitive indicators of liver cell damage, they were non-specific for this organ, and consequently no enzyme studied was a specific indicator of liver cell damage in the bustard.     

Diagnostic enzyme profile in houbara bustard tissues ( Chlamydotis undulata macqueenii )

We have reported tissue profiles of diagnostic enzymes in heart, liver, kidney, duodenum, pancreas, pectoral muscle and quadriceps muscle from houbara bustards (Chlamydotis undulata macqueenii). Enzymes studied included aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALKP), lactate dehydrogenase (LDH) and creatine kinase (CK). The data from our studies suggest that the tissue enzymes which are commonly used as clinical diagnostic tools in other species may also be used to evaluate tissue integrity in houbara bustards. However, although tissue enzyme patterns in the bustard showed some similarities compared with other avian species, there were also important differences. GGT and ALKP activities were predominantly present in the bustard kidney. CK appeared to be a sensitive indicator of muscle cell damage in the bustard. Although ALT, LDH and AST appeared to be sensitive indicators of liver cell damage, they were non-specific for this organ, and consequently no enzyme studied was a specific indicator of liver cell damage in the bustard.     

Does determination of serum aspartate aminotransferase contribute to the diagnosis of acute myocardial infarction?

Values for total lactate dehydrogenase (LD), LD isoenzymes, and serum aspartate aminotransferase (AST) were determined in 150 patients with acute myocardial infarction (AMI) and 130 non-AMI patients 24, 48, and 72 hours after admission. The authors assessed the diagnostic yield of a single determination of AST, LD, and three LD isoenzymes tests: LD-1 greater than LD-2; LD-1 greater than 90 U/L; LD-1/LD greater than 0.4. They also assessed the diagnostic accuracy of combined determination of AST with LD and AST with each of the above three LD isoenzymes tests. The efficiency of single determination of AST was better than that of LD (88% vs. 80%, 48 hours after admission). The most efficient single test for diagnosing AMI was the LD-1 greater than 90 U/L test (92%, 48 hours after admission). The efficiency of the combined AST/LD test was better than that of a single determination of each of the two enzymes (90% vs. 88% and 80%, 48 hours after admission). The highest efficiency was achieved, however, with combined determination of AST and any of the three LD isoenzymes tests. It was found to be more efficient than single determination of each of the LD isoenzymes tests (95.5-96% vs. 89-92.5%) and more efficient than the combined determination of the AST/LD test (95.5-96% vs. 89-90%). The authors conclude that AST should be determined in every patient with suspected AMI because its determination may contribute to the diagnostic yield of LD isoenzymes tests, especially in patients with AMI admitted 48-72 hours after onset of symptoms, when creatine kinase declined to near normal values.     

Metabolic muscle damage and oxidative stress markers in an America’s Cup yachting crew

Activities of enzymes involved in muscle damage [creatine kinase (CK) and aspartate aminotransferase (AST)] and levels of malondialdehyde (MDA) as a marker of oxidative stress were monitored in the plasma of 27 members of an America’s Cup yachting crew. The preventive benefits of allopurinol on muscle damage were also tested. In racing period A, the crew was divided into two groups according to their tasks on board. Blood samples from all 27 sailors were obtained before the start of a 5-day fleet race, after the last race, and after the ten match races. In period B, crew members were divided at random into two groups. One group (13 participants) received 300 mg/day of allopurinol 3 h before racing. The other ten members received placebo. Blood samples were collected just before and after the second round of the Louis Vuitton Cup. All participants showed increased CK and AST activities after the racing period A. The increase in CK activity was highest in sailors involved in strenuous physical work. At the end of period A, plasma MDA levels were higher in all participants as compared with non-participant athletes. In period B, a significant decrease in CK activity, but not in AST, appeared among participants receiving allopurinol. Plasma MDA decreased in sailors treated with allopurinol, but this reduction did not reach statistical significance. America’s Cup is a sailing sport with high physical demands, as shown by the increase in muscle-damage markers. Treatment with allopurinol appeared to decrease the levels of muscle damage markers.     

三种常见精神疾病心肌酶及心电图对比分析

目的：对比不同精神科疾病患者心肌酶及心电图情况,探讨心肌酶变化在不同精神科疾病患者诊断治疗方面的意义.方法：通过随机抽取既往1年住我院某病区的精神分裂症患者、双相情感障碍-躁狂发作、躁狂发作、双相情感障碍-抑郁发作、抑郁发作患者病历,对其入院次日清晨心肌酶检测结果,包括肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）、天门冬氨酸氨基转移酶（AST）的水平以及患者的心电图情况进行对比分析.结果：精神分裂症、躁狂发作及双相障碍-躁狂发作患者的心肌酶及心率有不同程度升高,并与抑郁发作和双相障碍-抑郁发作患者对比有统计学意义.结论：心肌酶的增高对于精神疾病诊断有一定临床参考意义.     

肌酸激酶MBmass对急性心肌损伤早期诊断的实验研究

目的：连续测定犬急性心肌损伤动物模型血清中肌酸激酶MBmass（CK-MBmass）、CK-MB活性、CK活性等心肌酶学标志物,观察CK-MBmass对急性心肌损伤早期诊断的价值。方法：采用球囊堵闭左冠状动脉前降支中远端的方法建立犬急性心肌损伤动物模型。在诸闭前、堵闭后每10min直至90min连续采静脉血各2ml,3000r／min离心10min取血清测定或置-40℃保存待测。采用微粒子酶联免疫分析法测定CK-MBmass。免疫抑制法测定CK-MB活性,速率法测定CK活性。观察急性心肌损伤后CK-MBmass、CK-MB活性、CK活性等心肌酶学标志物的动态变化及损伤心肌的组织学改变。结果：冠状动脉堵闭90min后,心电图可见明显心肌损伤性ST段上抬改变;血清CK-MBmass、CK-MB活性、CK活性等指标皆超出个体值的2倍以上,但未超出实验参考值的2倍;出现异常值时间CK-MBmass、CK-MB活性、CK活性分别为（30-45）min、（30-60）min、（45-90）min。结论：CK-MBmass可早期诊断急性心肌损伤。     

超敏肌钙蛋白Ⅰ检测在糖尿病心肌损伤早期诊断中的价值

目的 探讨在糖尿病心肌损伤的早期诊断中检测血清超敏肌钙蛋白Ⅰ（hs-cTnⅠ）的价值。方法 选取2017年1月~2019年1月本院收治的103例2型糖尿病合并心肌损伤患者为观察组,选取同期行健康体检的100例志愿者为对照组,分别检测两组血清中天门冬氨酸氨基转移酶（AST）、肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）、糖化血红蛋白（HbA1c）及hs-cTnⅠ水平并比较。结果 两组AST、CK、CK-MB水平比较,差异无统计学意义（P＞0.05）;观察组HbA1c及hs-cTnⅠ水平高于对照组,差异有统计学意义（P＜0.05）;在观察组患者中,HbA1c≤6.4%组与HbA1c＞6.4%组的患者AST、CK及CK-MB水平比较,差异无统计学意义（P＞0.05）,而HbA1c≤6.4%组hs-cTnⅠ水平低于HbA1c＞6.4%组,差异有统计学意义（P＜0.05）。结论 针对糖尿病心肌损伤,通过对患者hs-cTnⅠ进行检测,有助于疾病的早期诊断及治疗。     

The Influences of Thermal Stress on Serum Biochemical Parameters of Dromedary Camels and Their Correlation with Thyroid Activity

In order to study the influences of thermal stress on serum biochemical parameters of dromedary camels and their correlation with thyroid activity, blood samples were taken from the jugular vein of 40 clinically healthy Iranian dromedary camels from December to February (3 times: mean temperature 11°C) and from June to August (3 times: mean temperature 41°C). There were significant differences in the concentrations of serum total protein, glucose, blood urea nitrogen (BUN), sodium, potassium, calcium, inorganic phosphorus, triiodothyronine (T3) and thyroxine (T4) and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatine kinase (CK) and lactate dehydrogenase (LD) in heat stress and cold stress conditions (p<0.05). The concentrations of BUN, sodium, potassium, calcium, inorganic phosphorus and the activities of CK and LD in winter months were higher than summer months, and in contrast, the concentrations of total protein, glucose, T3 and T4 and the activities of AST, ALT and ALP were higher in summer than in winter (p<0.05). Thyroidal hormones (T3 and T4) showed significant correlations with serum total protein, glucose, BUN, AST, ALT, ALP, LD and CK. Our results revealed that very hot and cold conditions had a profound effect on serum biochemical parameters.     

N-terminal pro-B-type natriuretic peptide as a marker of blunt cardiac contusion in trauma

Cardiac contusion is usually caused by blunt chest trauma and, although it is potentially a life-threatening condition, the diagnosis of a myocardial contusion is difficult because of non-specific symptoms and the lack of an ideal test to detect myocardial damage. Cardiac enzymes, such as creatine kinase (CK), creatine kinase MB fraction (CK-MB), cardiac troponin I (cTn-I), and cardiac troponin T (cTn-T) were used in previous studies to demonstrate the blunt cardiac contusion (BCC). Each of these diagnostic tests alone is not effective for diagnosis of BCC. The aim of this study was to investigate the serum heart-type fatty acid binding protein (h-FABP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), CK, CK-MB, and cTn-I levels as a marker of BCC in blunt chest trauma in rats. The eighteen Wistar albino rats were randomly allocated to two groups; group I (control) (n=8) and group II (blunt chest trauma) (n=10). Isolated BCC was induced by the method described by Raghavendran et al. (2005). All rats were observed in their cages and blood samples were collected after five hours of trauma for the analysis of serum h-FABP, NT-pro BNP, CK, CK-MB, and cTn-I levels. The mean serum NT-pro BNP was significantly different between group I and II (10.3±2.10 ng/L versus 15.4±3.68 ng/L, respectively; P=0.0001). NT-pro BNP level >13 ng/ml had a sensitivity of 87.5%, a specificity of 70%, a positive predictive value of 70%, and a negative predictive value of 87.5% for predicting blunt chest trauma (area under curve was 0.794 and P=0.037). There was no significant difference between two groups in serum h-FABP, CK, CK-MB and c Tn-I levels. A relation between NT-Pro BNP and BCC was shown in this study. Serum NT-proBNP levels significantly increased with BCC after 5 hours of the blunt chest trauma. The use of NT-proBNP as an adjunct to other diagnostic tests, such as troponins, electrocardiography (ECG), chest x-ray and echocardiogram may be beneficial for diagnosis of BCC.     

双下肢骨折大鼠血液粘度及血清酶活性变化

目的:观察骨折对大鼠血液流变学及血清酶学的影响。方法:20只Wistar大鼠,分为对照组、骨折组。观察双下肢骨折后血液流变学指标以及血清AST、ALT、LDH、LDH-1、HBDH、CK、CK-MB、ALP等指标的变化。结果:骨折组大鼠高、中、低切变率下全血粘度及血浆粘度均显著高于对照组,且血清LDH-1、CK-MB、ALP活性显著高于对照组(P<0.01),而血清AST、ALT、LDA、HBDA、CK活性与对照组无统计学差异(P>0.05)。结论:骨折可致大鼠血液流变性异常以及某些血清酶释放增多,从而引起器官功能障碍。     

Creatine kinase isoenzyme profiles after exercise in the rat: sex-linked differences in leakage of CK-MM

Changes in creatine kinase (CK) activity and CK isoenzyme profiles in plasma after exercise were studied in rats in order to establish the source of the exercise-induced rise in CK activity. Male and female rats ran on a treadmill for 2 h and blood samples, taken before and after exercise, were assayed for total CK, CK isoenzymes and aminoaspartate transaminase (AST) activity. These enzymes were also assayed in homogenates of liver and several muscles. We found that the isoenzyme composition of liver, plasma and muscle did not differ between the sexes. However, the exercise-induced CK and AST responses did differ: CK and AST increased after exercise in males (101% and 15% resp.), but much less in females (47% and 1%). Although the isoenzyme profiles in rest did not differ, significant differences were observed after running: in males CK-MM inereased with 678%, but females only showed a 114% increase. In contrast, CK-BB showed a small increase that was about the same for both sexes (males 41%, females 35%). We conclude that both males and females show a small and similar increase in CK-BB activity after exercise, and that a large release of CK-MM from skeletal muscle, observed only in males, accounts for sex-linked differences reported earlier.     

传统心肌酶谱联合损伤相关蛋白IMA、TnI-Ultra检测对急性心肌梗死早期诊断的价值分析

目的 探讨肌酸激酶(CK)、肌酸激酶同功酶(CK-MB)、同型半胱氨酸(HCY)和乳酸脱氢酶(LDH)等心肌酶,联合血清缺血修饰清蛋白(IMA)和超敏肌钙蛋白I(TnI-Ultra)等心肌损伤相关蛋白检测在急性心肌梗死(acute myocardial infarction,AMI)早期诊断中的应用.方法 选取我院于2014年1月至2017年1月期间收治的AMI患者150例,病发后6h内采集静脉血,检测患者心肌酶谱(CK、CK-MB、HCY和LDH)及IMA和TnI-Ultra等生化指标.同期选取100例非AMI患者血液样本作为对照组.结果 150例AMI患者血清CK、CK-MB、LDH(U/L)和HCY(μmol/L)水平分别为:688.5±68.7、86.4±9.2、364.7±55.2和34.5±9.4.与对照组相比,CK和CK-MB水平明显升高(P<0.01),而LDH和HCY与对照组相比差异无统计学意义(P>0.05),但IMA(65.5±11.7 U/L)和TnI-Ultra(10.6±3.5μg/L)水平均明显升高,差异有统计学意义(P<0.01).结论 CK、CK-MB、HCY和LDH等心肌酶指标在AMI患者中有较高的阳性率,但某些非AMI类疾病也可能导致以上指标异常升高;IMA和TnI-Ultra等心肌损伤相关蛋白对AMI诊断有较高的特异性.心肌酶联合心肌损伤相关蛋白检测有助于AMI的早期诊断,对降低AMI风险具有重要意义.