DNA sequences coding for the muscle-specific subunit of creatine kinase have been isolated from cDNA libraries constructed from Torpedo marmorata electric organ. Clones were screened by differential in situ hybridization and hybrid-selected translation. The in vitro translation product of the selected mRNA was immunoprecipitated by anti-chicken creatine kinase antibodies and comigrated with Tor...

Rats were fed a 2% guanidino propionic acid diet for up to 18 weeks to induce cellular creatine depletion by inhibition of creatine uptake by this creatine analogue. Ultrastructural analysis of creatine depleted tissues showed that mitochondrial intermembrane inclusion bodies appeared in all skeletal muscles analysed, after 11 weeks of feeding. Heart had relatively few even after 18 weeks of an...

To establish optimum conditions for creatine kinase (EC 2.7.3.2) activity measurement with the creatine phosphate in equilibrium creatine reaction, we re-examined all kinetics factors relevant to an optimal and standardized enzyme assay at 30 and 25 degrees C. We determined the pH optimum in vaious buffers, considering the effect of the type and concentration of the buffer, as well as the influ...

Aim: The aim of the study was to investigate the effects of in vitro hemolysis on serum creatine kinase and creatine kinase MB isoenzyme activities with creatine kinase MB mass, troponin I and myoglobin measurements. Materials and methods: We prepared serum pools having analyte concentrations at normal and pathological values. Hemolysate was added into serum pools to obtain aliquotes with final...

We describe two cases, hospitalized patients, in whom the activity of creatine kinase (EC 2.7.3.2) isoenzyme-MB was above normal. Both are particularly noteworthy in that creatine kinase-BB and a macro creatine kinase form thought to be type II of mitochondrial origin were also present. The macro creatine kinase component in both cases co-migrated electrophoretically with creatine kinase-MM but...

The course of plasma catalytic activities of total creatine kinase, creatine kinase isoenzyme MB, total, cytoplasmatic and mitochondrial aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, glutamate dehydrogenase and concentrations of myoglobin, urea, acidic alpha 1-glycoprotein and creatinine were followed in 33 patients suffering f...

Bleeding risk with antiplatelet therapy is an increasing clinical challenge. However, the inter-individual variation in this risk is poorly understood. We assessed whether the level of plasma creatine kinase, the enzyme that utilizes ADP and phosphocreatine to rapidly regenerate ATP, may modulate bleeding risk through a dose-dependent inhibition of ADP-induced platelet activation. Exogenous cre...

Sera from patients with myocardial infarction and cardiac arrhythmias were analyzed for myoglobin concentration and the activities of total creatine kinase, creatine kinase isoenzyme-2, and lactate dehydrogenase isoenzyme-1 at the time of hospital admission and during the first few days of hospitalization. The nine patients with a final diagnosis of myocardial infarction had abnormally high val...

Macro creatine kinase (Macro CK), a macro enzyme, is a major cause of misdiagnosis of myocardial infarction upon determination of total creatine kinase and creatine kinase isoenzyme levels. It presents in elderly female patients with an approximate prevalence of 1 %. Based on composition, there are two major types of macro CK Type 1 macro CK is a complex of Type 1 being an immune complex of cre...

Serum and plasma myoglobin and creatine kinase-MB catalytic activity were analysed in 157 patients admitted within 2 hours of the onset of chest pain (58 were retrospectively recognized as acute myocardial infarction). Serum and plasma values were highly correlated for both myoglobin and creatine kinase-MB. Plasma myoglobin appeared to be more sensitive than creatine kinase-MB for the early dia...