Interesting information about creatinine can be found in the works of L. Rosenhtraukh and L. Robinson (Cardiovasc. Surgery) which concludes that the substance in the form of phosphocreatine participates in the regulation of the circulation of cellular calcium.

Calcium is an extremely important regulator of cellular processes, e.g. crucial for the proper function of the cardiac muscle. Its concentration inside the cell is several thousand times lower than in the extracelullar space. Only a little increase in the concentration of the element in the cellular cytoplasm leads to significant metabolic results.  For instance, it initiates the occurrence of the force impulse in the cardiac muscle. However, in order that the force impulse can be generated further, that is for the heart to work properly, the concentration of calcium has to decrease immediately.

And here the beneficial phosphocreatine begins its action. It provides energy in the form of ATP needed to “pump out” calcium from the cytoplasm. Additionally, it directly reacts with calcium and binds it, reacts with phospholipids of cell membranes and inhibits the uncontrolled inflow of calcium into cardiomyocytes. Thus it facilitates the circulation of cellular calcium and is conducive to the proper heart action.