Contributions of Alexey Vereninov to the Study of Ion Permeability and Homeostasis

The review is devoted to Alexey Vereninov's research in the field of cell permeability and ion homeostasis. Particular attention is paid to the modeling approach developed in the study of frog striated muscles and subsequently applied to other cell types. Biologically relevant ways by which the muscles were studied and the model that was constructed determines the overall nonreductionist approach of the research. In the first study of excitability in invertebrate tissues and organs Vereninov used techniques and methods derived from his teacher Dmitry Nasonov. From 1963 to 1971, he tested membrane and phase concepts of bioelectrogenesis using isolated fibers and whole sartorius muscles. Both mechanistic and theoretical models have been used in the study of “salt potentials”. The properties of muscles considered in these models are relevant to both the phase and membrane models. Vereninov’s work, therefore, led to reconciliation between the two theories. In studies performed in 1971 and 1976 Vereninov presented a nonreductionist approach to the study of ion and osmotic balance in animal cells. Using the concept of cell permeability, he developed a method to analyze potassium permeability by combining electrophysiological and ionic data. In 1980-1983 Vereninov applied Ussing's criterion to study the role of passive permeability in the ion balance of muscles in a bi-ionic system. These studies were carried out under specific ionic conditions that allow the distinction between passive and active components of ion transport. Under these conditions, sodium was actively transported, and potassium exhibited both active and passive transport. Moreover, in a bi-ionic system with rubidium and potassium, some unidentified transport component was also present. Therefore, instead of Ussing's criterion, the application of which is restricted to specific experimental conditions, the analysis of ion fluxes was carried out using mathematical modeling.