Aims: 

Changes of elemental concentrations in cardiomyocells are supposed to develop during ischemia. In the given investigation Electron Probe Microanalysis was applied to determine the cytoplasmic elemental (K, Na, Cl) contents in cardiac cells of rat under acute ischemia.

Methods: 

The experiments were carried out on male Wistar rats. An isolated heart was perfused by Langendorff's procedure. Ischemic depletion was created by perfusion with Tirode's solution deep deoxygenated and in the absence of glucose. An isolated cardiac papillary muscle was frozen in liquid propane and placed in a cryomicrotome chamber, where it was cut at -30°C into 10 mm thick cryosections. After low-temperature dehydration in vacuum the cryosections were mounted in the holder of a JSM-U3 microanalyzer microscope (JEOL, Japan). The potassium, sodium or chlorine concentration in the cell was determined from the intensity of the Ka line in the characteristic spectrum of an element that was excited in a sample by accelerated electrons of the probe.

Results: 

It was found that the initial phase of acute ischemia was defined by the potassium deficiency (96±2 mM vs. control 122±1 mM, these and all results below are presented as mean and standard deviation), and accumulation of sodium (44±2 mM vs. control 36±1 mM) and chlorine (45±1 mM vs. control 24±1 mM) in cardiac myocells.

Conclusion: 

It should be noted that changes of the sum in main intracellular cations (K⁺, Na⁺) were not equilibrated with the increased chlorine concentration. This result can be accounted for by the appearance of ionic (K⁺ and Cl^-) electro neutral transports coupled with removing the lactate anions produced in cardiomyocytes during anaerobic glycolysis.