meta-Analysis of Acid-Base and Redox Processes within the Mitochondrial Matrix, Cytoplasm, Intercellular Medium, and Blood Based on the Tensor Approach

The acid-base balance (ABB) is the most important indicator of homeostasis; over the past half century, it has been assessed in clinical practice following the Boston or Copenhagen schools or relying on the physicochemical interpretation proposed by P. Stewart, which changed the emphasis from direct pH values to the generalized state of the electrochemical equilibrium of blood. Today, it is generally recognized that all the three approaches to assessing the ABB have weaknesses and do not have convincing clinical advantages. Since it was experimentally established that with metabolic acidosis, 57% of buffering occurs intracellularly, it is more appropriate to consider the ABB not as a purely isolated blood indicator, but within the framework of energy metabolism (dissimilation), which is the consequence of redox reactions within the mitochondrial matrix, intermembrane space, and cell cytoplasm; this can be solved by mathematical modeling. The use of tensor notation for mathematical model equations is not only the adoption of standardization rules, but a far-reaching ideology of invariance of these equations (preservation during the transformations of a certain group). The present study shows that the acid-base and redox homeostasis in mathematical model equations can be interpreted as “free-play” (variations within the established boundaries during the transformations of a certain type) for specially formulated tensor invariants.