Differentiation of Myoblasts in Culture: Focus on Serum and Gamma-Aminobutyric Acid

There are many facts about the possible role of gamma-aminobutyric acid (GABA) in the development and differentiation of cells not only in nervous but also in muscle tissue. In the present study, a primary culture of rat skeletal muscle myocytes was used to evaluate the correlation between the content of GABA in the cytoplasm and the processes of myocyte division and their fusion into myotubes. The effect of exogenous GABA on the processes of culture development was also estimated. Since the classical protocol for working with myocyte cultures involves the use of fetal bovine serum (FBS) to stimulate cell division (growth medium) and horse serum (HS) to activate the differentiation process (differentiation medium), the studies were carried out both in the medium with FBS and with HS. It was found that cells grown in medium supplemented with FBS contain more GABA compared to cultures growing in medium supplemented with HS. Addition of exogeneous GABA leads to a decrease in the number of myotubes formed in both media, while the addition of an amino acid to the medium supplemented with HS had a more pronounced inhibitory effect. Thus, we have obtained data indicating that GABA is able to participate in the early stages of skeletal muscle myogenesis by modulating the fusion process.