Creatin phosphokinase

Fig. 4. Requirements, substrates, and products of Mo-nitrogenase catalysis, where I is the MoFe protein II the Fe protein and Pi is inorganic phosphate. The generating system is composed of creatine phosphate and creatine phosphokinase to recycle the inhibitory MgADP produced during catalysis to...

Takahashi, R. Ushikubo, S. Oimomi, M. and Shinki, T. Creatine phosphokinase isoenzymes of human heart muscle and skeletal muscle. Clin. Chim. Acta (1972),... 

CK Creatine phosphokinase CKMB The myocardial-specific isoenzyme of creatine phosphokinase Cl The chemical symbol for chloride CL Chemiluminescent CLA Cutaneous lymphocyte antigen CL18/6 Anti-ICAM-1 monoclonal antibody... 

Succinylcholine 1-1.5 mg/kg IV up to 150 mg total dose ° Contraindications may include use in patients with a personal or family history of malignant hyperthermia, extensive/severe burns, myopathies with elevated creatine phosphokinase, penetrating eye injuries, pre-existing hyperkalemia, narrow-angle glaucoma, and disorders of plasma pseudocholinesterase... 

Check periodic creatine phosphokinase levels with prolonged infusions (especially if patient is receiving concomitant corticosteroid pharmacotherapy)... 

MM An isoenzyme of creatine phosphokinase OU Oculus uterque (each eye)... 

Creatine Phosphokinase (CPK) (rabbit skeletal muscle Calbiochem) Resuspended with deionized RNAse free water to a final concentration of 14 mg/ml and stored at —20°. 

CPK creatine phosphokinase FRAP fluorescence recovery after photolysis... 

Five repeated exposures of 200 ppm for 12.5 min every 4 d resulted in increased cardiac-specific creatine phosphokinase activity in the blood (pooled data measured at 2 h after the first, third, and fifth exposures) and ectopic heart beats during the first 2 min after injection of norepinephrine (after the fifth exposure) but failed to induce cardiac lesions (histopathologic examinations at 14 d postexposure) (O Flaherty and Thomas 1982). The rats were restrained and anesthetized. 

Sidell, F.R., Calver, D.L. and Kaminskis, A. (1974). Serum creatine phosphokinase activity after intramuscular injection. JAMA 228 1884-1887. 

Rat 5 x/20 d (Long-Evans) 4 d intervals 12.5 min/x Cardio 192 M (increased creatine phosphokinase activity) O Flaherty and Thomas 1982 HCN... 

Example In order to measure the activity of an enzyme E, such as creatine phosphokinase (CPK), the concentration of the substrate S, for instance creatine, should be in large excesses so that the products measured shall be in the linear portion of the curve (Part A ) in Figure 2.5. 

Enzymes activities are particularly sensitive to the anticoagulant used in collecting the specimen. Heparin inhibits acid phosphatase (W16) and muramidase (Z5). Amylase activity is inhibited by oxalate or citrate (MIO), and lactic dehydrogenase and acid phosphatase lose activity in oxalate (C2). Alkaline phosphatase is stable in oxalate, oxalate-fluoride, or heparin, but 25 mAf citrate inhibits 50% of the activity, and as little as 50 mlf EDTA is completely inhibitory (B19). Leucine aminopeptidase is inhibited by EDTA, as is creatine phosphokinase (F3). Amylase activity has been reported to be only 83% of that in serum when oxalate or citrate-plasma is used (MIO). Heparin plasma appears to have no inhibitory effect. Despite the fact that clotting factor V is not stable in oxalate or EDTA, these are often used as anticoagulants to obtain plasma for prothrombin determinations (Z2, Z4). 

Creatine phosphokinase activity has been reported to be minimally inhibited by hemolysis. Hemoglobin concentrations of 1.25 g/100 ml inhibit 5% and 2.5 g/100 ml, 12% (N5). However, in methods utilizing adenosine diphosphate in the reaction mixture, hemolysates containing 100 mg of hemoglobin per 100 ml may have apparent activities of 5-100 units/liter. The activity is presumably related to adenylate kinase in the erythrocyte (S33). In methods utilizing adenosine diphosphate in a coupled enzyme reaction with hexokinase and glucose-6-phosphatase, the inhibitory effect can be eliminated by adding sufficient adenosine mono-... 

Intramuscular injections have been shown to produce elevations in serum enzyme activities presumably due to either inflammatory areas in the muscle or actual breakdown of cells and release of enzyme. In one study, preinjection values of creatine phosphokinase were in the normal range of 24-100 units. Multiple intramuscular injections of penicillin, diuretics, and narcotics every 6 hours caused the creatine phosphokinase values to rise to levels between 160 to 240 units, or up to 2.5 times the upper limit of normal. When the injections were stopped, the creatine phosphokinase values returned to normal within 48 hours (B7). Similar observations of aspartate aminotransferase activities were made in patients receiving intramuscular injections of penicillin every 4 hours. Activities rose to values as high as 200 units. Other workers have reported injection related serum creatine phosphokinase elevations following intramuscular administration of chlorpromazine and suxamethonium (HIO, M11,T6). 

An intriguing study has been reported by Griffiths (Gil) of medical students participating in an annual London to Brighton Stroll. Specimens for creatine phosphokinase analysis were drawn before the march, at the midway point (25 miles) and at the end of the march (53 miles). At the 25-mile point, the mean creatine phosphokinase activities were increased 7-fold, and at the end of the march there was a 24-fold increase. In Table 9 are shown the values in several representative subjects in the study (Gil). 

Values are expressed as units of creatine phosphokinase activity. 

IM use May increase creatine phosphokinase levels. Use of the enzyme determination without isoenzyme separation, as a diagnostic test for acute Ml, may be compromised. 

Skeletal muscle effects All statins have been associated with myalgia, myopathy (ie, muscle pain, tenderness, or weakness with creatine phosphokinase [CPK] values above 10 times the ULN), and rhabdomyolysis. Factors that may predispose patients... 

Skeletal muscle effects The use of fibrates alone, including fenofibrate, may occasionally be associated with myopathy. Treatment with drugs of the fibrate class has been associated on rare occasions with rhabdomyolysis, usually in patients with impaired renal function. Consider myopathy in any patient with diffuse myalgias, muscle tenderness or weakness, or marked elevations of creatine phosphokinase levels. 

Adverse events occurring in at least 3% include abnormal liver function tests, increased ALT and AST, increased creatine phosphokinase, respiratory disorder, abdominal pain, back pain, headache. 

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