An investigation into creatine kinase and other plasma enzymes in thyroid disorders.

The relationship between plasma protein bound iodine (PBI) level and creatine kinase (CK) activity was investigated in 143 males and 528 females suspected of various thyroid disorders; there was significant negative correlation between low PBI level and raised CK activity. CK, aldolase, lactate dehydrogenase (LD), aspartate transaminase (AST), and alanine transaminase (ALT) activities were determined in plasma from patients with reduced PBI levels; apart from CK, LD was the only enzyme increased in an appreciable number of cases. A further series of specimens was collected from 66 patients with low PBI levels and the CK isoenzymes investigated. In all of these MM was the main form present; a trace of MB was found in 6. These findings do not explain the elevation of CK in hypothyroidism which may be a non-specific effect.     

Source of elevated serum mitochondrial creatine kinase activity in patients with malignancy

Mitochondrial creatine kinase (CK-mit) is increased in cancer tissues of the digestive tract. There is no difference in molecular weight, electrophoretic and kinetic properties between the isoenzymes extracted from the tumor and those from the adjacent normal tissues. High non-CK-M/total CK activity ratios in some sera from cancer patients probably reflect leakage of CK-mit from the tumor tissues.     

Detection of cardiac-specific creatine kinase isoenzyme in sera with normal or slightly increased total creatine kinase activity.

We describe a spectrophotometric kinetic assay for detecting creatine kinase MB isoenzyme activity in the 1 to 10 U/liter range. The MB isoenzyme was isolated [Clin. Chem. 20, 36 (1974)] and assayed (Rosalki method) with an Abbott ABA-100. Good reproducibility was demonstrated for MB isoenzyme activities near 1 U/liter (CV = 2.6%). Sera with normal or slightly increased total creatine kinase activity were evaluated. Sera of 14 patients with acute myocardial infarction contained, per liter, 84 to 236 U of total creatine kinase activity and 4.6 to 28.0 U of isoenzyme MB activity; corresponding ranges for sera from healthy lab technicians and patients with noncardiac disease were 36 to 277 and 0 to 2.6 U. MB isoenzyme activity for infarction patients rose and fell sharply within three days after the infarction. Atypical time-course patterns, MB isoenzyme activity remaining abnormally great for five days, were observed in serum from patients with prolonged atrial fibrillation and congestive heart failure or cardiomyopathy; the BB isoenzyme (1 to 5 U/liter) was also detected in sera of such patients but was absent in sera from infarcation patients. Quantification of column-isolated MB by the assay described is rapid, easy, specific, and extremely sensitive for measuring MB in the 1 to 10 U/liter range.     

The isoelectric focusing of creatine kinase variants: II. The heterogeneity of creatine kinase in human serum with normal and elevated catalytic concentrations

An effective and reliable method for the quantitative estimation of creatine kinase-MB, creatine kinase-MM variants and mitochondrial forms of creatine kinase in serum is presented. The high resolving power of isoelectric focusing allows the use of tetrazolium salts and meldola blue for the quantitative measurement without interfering non-specific reduction. The addition of thiol compounds to the agarose medium increases the sensitivity of the method, due to the inhibition of sulfhydryl group oxidation, and prevents enzyme degradation, which is a possible cause of an artificial heterogeneity. Depending upon the type of muscle and the degree of cell damage, we found 3-4 creatine kinase-MM sub-bands in sera with activities below 80 U/l. At elevated creatine kinase activities 3-11 creatine kinase-MM sub-bands were found. The appearance of creatine kinase-MB in serum indicates that damage has occurred to certain organs, especially the cardiac muscle. An organ with moderate or massive cell damage could release, in addition to the sarcoplasmatic creatine kinase variants, other forms with more alkaline isoelectric points (mitochondrial creatine kinase). The presence of such bands in serum of patients correlates with poor prognosis. Besides the separation of creatine kinase-MM sub-bands, creatine kinase-MB, creatine kinase-BB and of macroforms 1 and 2, the advantage of this method is the detection of mitochondrial creatine kinase forms, which in cellulose acetate electrophoresis migrate with creatine kinase-MM.     

Determination of creatine kinase isozymes in sera and tissues of patients with various lung carcinomas

Three creatine kinase isozymes (CK-BB, CK-MB and CK-MM) were estimated by immunoassay in tumor tissues and in sera of patients with various lung carcinomas. CK-BB was increased in small cell carcinoma, but not in other lung carcinomas. CK-MM and CK-MB were not increased in any types of carcinoma. Serum CK-BB was increased in all types of lung carcinoma examined, while serum CK-MM and CK-MB were within normal limits in all patients. Serum CK-BB of healthy adults was estimated as 0.32 +/- 0.14 (mean +/- SD) ng/ml, ranging from 0.11-0.68 ng/ml. If CK-BB values above 1.0 ng/ml were considered abnormal, elevation occurred in 28/40 (70%) of patients with small cell carcinoma, 25/67 (37%) with adenocarcinoma, 21/51 (41%) with squamous cell carcinoma, 4/11 (36%) with other carcinoma of the lung and 10/42 (24%) with lung tuberculosis. Since serum CK-BB with lung cancer changed in parallel with the clinical course, this isozyme may be a marker for monitoring the clinical course, especially in small cell carcinoma of the lung.     

Light sensitivity of creatine kinase in control sera

The light sensitivity of creatine kinase in different control sera was investigated. Control sera were dispensed into reaction vessels, then exposed for 4 h at 25 degrees C to a light source equivalent in intensity to normal laboratory illumination. In 12 out of 22 control sera, the catalytic concentration of the creatine kinase fell by 25-63%. Under the same conditions, in patient sera, creatine kinase is stable. In the "light sensitive" control sera, the instability of the enzyme increased with the intensity of illumination. When exposed to sunlight creatine kinase was unstable in all the investigated control and patient sera. The addition of mercaptoethanol stabilized the creatine kinase in "light sensitive" control sera. The reason for the different light sensitivity of different control sera is not known.     

Detection of creatine kinase BB isoenzyme in sera of patients undergoing aortocoronary bypass surgery.

Creatine kinase BB isoenzyme (CK-BB) was detected intraoperatively in 22 of 25 patients undergoing aortocoronary bypass surgery, both in the coronary sinus and in the mixed venous blood. In a group of 10 patients in whom selective intracavitary profound hypothermic arrest was used, CK-BB values were lower than in another group of 10 patients, in whom controlled ventricular fibrillation with moderate total body hypothermia was instituted. This latter group also had higher levels of CK-MB. Patients who developed acute myocardial infarction immediately prior to or during the surgical intervention had the highest CK-BB values. This enzyme appeared as early as 15 minutes after the institution of cardiopulmonary bypass and disappeared within 6 hours. It is considered that part of the BB isoenzyme in serum of patients undergoing heart surgery is of myocardial origin.     

肝硬化患者血清肌酸激酶、肌酸激酶同工酶-MB水平与Child-Pugh评分的相关性分析

目的探讨肝硬化患者血清肌酸激酶(CK)、肌酸激酶同工酶-MB(CK-MB)水平与Child-Pugh评分的相关性。 方法分析2013年4—7月确诊的肝硬化患者临床资料。入选标准：(1)肝硬化诊断符合全国传染病与寄生虫病防治学术会议诊断标准;(2)既往无冠心病、高血压、心肌病病史;(3)心电图无ST-T动态变化;(4)cTnI正常。排除标准：(1)脾脏切除史;(2)合并肝癌,肝移植者,进行干扰素、免疫抑制剂或抗病毒治疗者;(3)存在血液系统疾病或严重感染性疾病。对患者入院进行Child-Pugh分级测评,记录各组患者临床基线资料,包括年龄、性别、原发肝脏疾病、肝功能、血常规等,分别采用酶动力法和免疫抑制法,检测入选患者的CK和CK-MB水平。比较患者CK、CK-MB水平及CK-MB/CK比值,采用有序Logistic回归分析肝硬化患者CK-MB/CK比值与Child-Pugh评分之间的相关性。 结果总共入选符合标准的肝硬化患者121例,平均年龄(56.67±10.88)岁,其中男性89例,乙肝肝硬化患者72例。Child-Pugh C级患者年龄明显高于Child-Pugh A、B组患者(P＝ 0.021),3组患者γ-谷酰转肽酶、CK[(82.18±23.60)U/L、(98.22±33.13)U/L、(117.05±27.31)U/L,F＝23.248,P<0.01)]、CK-MB[(29.77±12.75)U/L、(63.26±36.35)U/L、(69.76±27.05)U/L、F＝20.588,P<0.05)]、CK-MB/CK比值(0.36±0.08、0.54±0.26、0.75±0.30,F＝31.558,P<0.05)、凝血酶原活动度(PA)[(71.77±14.88)%、(56.82±16.61)%、(41.73±11.43)%,F＝54.483,P<0.05)]、血红蛋白(HGB)[(138.21±8.24)g/L、(108.16±23.60)g/L、(78.52±23.64)g/L,F＝95.752,P<0.05)]以及血小板(PLT)[(153.86±92.59)g/L、(108.38±51.90)g/L、(93.88±54.51)g/L,F＝12.965,P<0.05)]水平差异均有统计学意义。3组患者原发肝脏疾病、谷草转氨酶(ALT)、谷丙转氨酶(AST)以及肌酐水平(SCr)差异均无统计学意义。对资料进行有序Logistic回归分析,发现CK-MB/CK比值对Child-Pugh评分有显著影响,其OR值为e^－0.98＝0.375,提示CK-MB/CK比值>0.30时,Child-Pugh分级C级的可能性为CK-MB/CK<0.30时的2.67倍。 结论肝硬化患者CK-MB/CK比值与Child-Pugh分级严重程度密切相关。     

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)     

Evaluation of the optimized bioluminescent assay for the determination of total creatine kinase and creatine kinase MB activities

A very sensitive, optimized bioluminescent assay for certain kinase and creatine kinase MB activities is tested. We evaluated reagent blanks, sensitivity, precision and compared the results with those of the spectrophotometric immunoinhibition test. The main advantage of the new method is a detection limit of less than 1 U/l which, together with a high precision (s = 0.1 at detection limit), allows determinations of the creatine kinase MB activity even in normal sera in about 20 minutes. A disadvantage of the manual procedure is that it may be necessary to include up to five pipetting steps.     

The origin of plasma creatine kinase 1, detected in patients during and following open heart surgery

Plasma creatine kinase 1 (CK-1) was detected intra-operatively in 6 out of 6 patients and postoperatively in 15 out of 22 patients, undergoing cardiac surgery. A transient increase in plasma levels of creatine kinase 2 (CK-2) and total creatine kinase (CK-tot.) activity was observed in all patients. The disappearance rates for the 2 isoenzymes in the circulation were CK-1: Kd = 4.7 X 10(-3) min-1, and CK-2: Kd = 0.60 X 10(-1) min-3. Analysis of vessel and heart tissue showed that the saphenous vein contained mainly CK-1; high activities of all three isoenzymes were found in the parts of the heart investigated. Most probably, both CK-1 and CK-2 are liberated from injured cardiac tissue.     

Effect of light and temperature on the stability of creatine kinase in human sera and controls.

Commercial control preparations were exposed to light at room temperature for as long as 24 h. Decreases in creatine kinase activity in seven of the nine controls ranged from 28.8 to 83.3%. When these controls were protected from light and stored at various temperatures, the decrease in activity was either eliminated or substantially reduced, indicating that the decreased activity in the presence of light was not due entirely to thermal inactivation. In the absence of oxygen, light had little effect on creatine kinase suggesting that light inactivation is a light-catalyzed oxidative process. The decreased activity observed when some of the controls were exposed to light was not completely restored by incubating with dithiothreitol before analysis. However, increases in creatine kinase activity ranging from about 37 to 176% were observed when freshly prepared controls were pre-incubated with dithiothreitol. Neither light nor dithiothreitol had any effect on the creatine kinase activity in two of the nine controls. When human sera were exposed to light for 24 h, the largest decrease in activity was about 15%. Incubation of fresh human sera with dithiothreitol before analysis caused an average increase in activity of approximately 10%.     

Comparison of serum creatine kinase and creatine kinase MB activities post marathon race versus post myocardial infarction

Serial total creatine kinase (CK) and CK MB activities were determined in the serum of seven runners following a marathon race and compared to enzyme activities in the sera from five patients following acute myocardial infarction (AMI). In the runner's sera, total CK and CK MB activities were significantly elevated at 1, 24, 48 and 72 hours post marathon race when compared to the 1 hour pre-marathon samples (p < 0.01). Serum CK MB activities peaked at 24 hours in both groups of subjects. The MB activities 24 hours following the marathon were substantially higher (91 ± 30 U/l; mean ± SD) than the MB activities 24 hours following AMI (46 ± 38 U/l). However, the percentages of CK MB 24 hours following the marathon and AMI were almost identical (7.0 ± 2.4% and 7.2 ± 2.3%, respectively). Furthermore, CK and CK MB clearances were significantly prolonged (p < 0.02 and p < 0.001, respectively) following the marathon race (T $\text{1}\text{2}$ CK, 49 hours; T $\text{1}\text{2}$ CK MB, 29 hours) as compared to following AMI (T $\text{1}\text{2}$ CK, 27 hours; T $\text{1}\text{2}$ CK MB, 12 hours). These results suggest release of CK MB from the skeletal muscle of marathon runners. Therefore, we recommend that elevation of CK MB in the range indicative of myocardial damage be interpreted with caution in long-distance runners.     

The presence of creatine kinase bb isoenzyme in patients with prostatic cancer

Creatine kinase BB isoenzyme (CK-BB) was detected in abnormal amounts in serum samples from 11 of 46 patients with Stage D carcinoma of the prostate by electrophoresis. Thirteen of 46 Stage D patients had elevated acid phosphatase values and 10 of these 13 had elevated CK-BB. CK-BB elevations were less frequent in earlier stages of prostatic cancer; Stage C: 0 of 35, Stage B: 1 of 26, Stage A: 0 of 3 and none in a group of 35 with BPH, prostatitis and bladder cancer. Results of CK-BB by a specific radioimmunoassay correlated well with those obtained by electrophoresis in most cases. Several patients were followed over time and data on CK-BB is presented for this interval. The origin of the CK-BB is still unclear. The BB isoenzyme predominates in prostatic tissue and CK-BB is the fetal form of the enzyme in human muscle and myocardium. The increase in serum CK-BB may be related to increased release of the isoenzyme, either from the prostate itself or from a metastatic lesion, or may represent a release of the fetal form of the enzyme from dedifferentiated tumor tissue.     

Spurious brain creatine kinase in serum from patients with renal disease.

Creatine kinase isoenzyme I(BB) is generally not detectable in normal serum, and its occurrence in serum has been documented in only a few disease states. In particular, increased activity of this isoenzyme has been reported in association with chronic renal failure, hemodialysis, and renal transplantation. The present study demonstrates that the apparent creatine kinase observed in the serum of such renal patients is an artifact, observed as a result of measuring creatine kinase isoenzymes by fluorescence. Our observations resemble those of McKenzie et al. [Clin. Chim. Acta 70, 333(1976)] concerning an artifact in the fluorometric determination of lactate dehydrogenase isoenzymes in the sera of patients with end-stage renal failure. The artifact binds to albumin, is not a protein, and occurs in some normal sera at very low concentrations. This artifact can be mistakenly identified as isoenzyme I in renal-disease patients if CK isoenzymes are determined fluorometrically.