No abstract

An atypical creatine kinase (CK) isoenzyme migrating cathodically to CK-MM in the electrophoresis was observed as response to the embolization of the right hepatic artery in two patients with liver metastasis. The time course of the atypical CK release was compared to that of tumor secretion products, i.e., insulin and 5-hydroxy-in-dol-acetic acid. The CK isoenzyme probably reflects a mitochondrial breakdown of the metastasis in question. The influence of the treatment on liver function was characterized by a marginal augmentation of ASAT and ALAT and by a small but significant leakage of mitochondrial glutamate dehydrogenase. In addition to the atypical CK, CK-BB, and CK-MB isoenzymes were found in the serum of the patient with primary carcinoid carcinoma.

Summary:1. Two methods for the Separation and Demonstration of creatine kinase isoenzymes are described i.e. electrophoresis on cellulose acetate and on electroendosmosis-low agarose.2. The fluorescence of NADPH äs an indicator for the creatine kinase bands was used in both methods.3. The methods proved to be specific, reliable and highly reproducible, and allow a rather large number of samples (12 -18) to be anälysed in one run within a relatively short time.

|Summary: Creatine kinase isoenzymes in cytosolic and mitochondrial fractions from human cardiac tissues i· were studied by analytical and preparative isoelectric focusing (IEF), electrophoresis and immunoinhibition. ;Analytical IEF on agärose gels revealed many creatine kinase variants in human cardiac cytosol prepared ! by extraction with a hypotonic medium. The bands located at approximately pH 5.5 were shown to contain creatine kinase-MB and minute creatine kinase-BB bands by electrophoresis. Two bands which focused closely together in IEF (pH 6.85-7.0) showed an electrophoretic migration pattern similar to creatine kinase-MM. One of them (IP 6.85) showed a complete Inhibition by anti-creatine kinase-M antibodies, whereas the other showed only 50% Inhibition.Increasing the salt concentration of tris-HCl (0.1 mol/1) in the extraction medium resulted in additional creatine kinase variants, They were characterized by high alkaline isoelectric points and were not inhibited by anti-creatine kinase-M antibodies. These variants corresponded to two cathodic bands in electrophoresis. iThe treatment of washed mitochondria with phosphate buffer resulted in a release of mitochondrial variants with differestt isoelectric points, äs shown by analytical IEF in agärose gels. l The saine pattern was pbtained by using preparative IEF. Variants with high alkaline isoelectric points gave rise,to two cathodic bands üpon electrophoresis. These two bands resembled those present in cytosol after extraction with high salt concentration. No complete Inhibition with anti-creatine kinase-M was observed in l any of the eluates. ! lThe mitochondrial variants exhibited different affinities towards creatine phosphate and ADR Variants with ,;j higher alkaline isoelectric points showed lower Äm-values for these Substrates than those with less alkaline isoelectric points.

Summary: 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 resölving power of isoelectric focusing allows the use of tetrazolium salts and meldola blue for the quantitative measfurement without interfering non-specific reduction.