Isotachophoretic analyses of metabolites of cardiac and skeletal muscles in four species.

We studied ATP and concentrations of other metabolites in cardiac and skeletal muscles from different species (frog, hamster, guinea-pig, and dog), using analytical capillary isotachophoresis. The method had several advantages for quantitative analysis of tissue metabolites: short separation time, high sensitivity, high resolution, and good reproducibility. It was also possible to detect a number of compounds simultaneously, including ATP, ADP, AMP, cyclic AMP, creatine phosphate (CP), inosine monophosphate, NAD, NADH, glucose-6-phosphate, pyruvate, and inorganic phosphate. Generally, the concentrations of high-energy phosphates (ATP and CP) in the cardiac muscle were significantly lower than those in the skeletal muscle, in all species tested, except for hamster where the concentration of CP in the skeletal muscle was comparable to that in the cardiac muscle. In mammals, ATP and CP concentrations were comparable in the atrium and ventricle while the concentration in the frog ventricle was significantly higher than that in the atrium. The data obtained by this isotachophoretic analysis were comparable to the data reported by the use of other conventional analytical methods. The significance and reliability of isotachophoresis in the determination of the various metabolites in the cardiac muscle were discussed.