Understanding the Effects of Trenbolone Acetate, Polyamine Precursors, and Polyamines on Proliferation, Protein Synthesis Rates, and the Abundance of Genes Involved in Myoblast Growth, Polyamine Biosynthesis, and Protein Synthesis in Murine Myoblasts

Simple Summary Anabolic hormones, such as estradiol and testosterone, are known to promote skeletal muscle growth in many different mammalian species. However, there are several different concerns with using anabolic hormones to improve or remedy skeletal muscle growth. As such, natural growth-promoting alternatives to anabolic hormones are needed. Previous research suggests that one mechanism through which anabolic hormones improve proliferation and protein synthesis within skeletal muscle is through modulation of the polyamine biosynthetic pathway. Polyamines are naturally occurring amino acid derivatives that are known to be potent stimulators of growth. As such, the purpose of this study was to examine the effects of anabolic hormones, polyamine precursors, and polyamines, relative to proliferation, protein synthesis rates, and messenger RNA expression in cultured murine myoblasts. The results demonstrate that anabolic hormones, polyamine precursors, and polyamines increase proliferation and anabolic hormones increase protein synthesis rates. Furthermore, polyamines and their precursors alter expression of the genes involved in polyamine biosynthesis, proliferation, and protein synthesis. However, additional research is needed to further investigate the relationship between anabolic hormones and polyamines relative to skeletal muscle growth to determine if polyamines and their precursors can be utilized as natural growth-promoting alternatives to anabolic hormones. Abstract Research suggests that androgens increase skeletal muscle growth by modulating polyamine biosynthesis. As such, the objective of this study was to investigate effects of anabolic hormones, polyamine precursors, and polyamines relative to proliferation, protein synthesis, and the abundance of mRNA involved in polyamine biosynthesis, proliferation, and protein synthesis in C2C12 and Sol8 cells. Cultures were treated with anabolic hormones (trenbolone acetate and/or estradiol), polyamine precursors (methionine or ornithine), or polyamines (putrescine, spermidine, or spermine). Messenger RNA was isolated 0.5 or 1, 12, or 24 h post-treatment. The cell type had no effect (p > 0.10) on proliferation, protein synthesis, or mRNA abundance at any time point. Each treatment increased (p < 0.01) proliferation, and anabolic hormones increased (p = 0.04) protein synthesis. Polyamines increased (p < 0.05) the abundance of mRNA involved in polyamine biosynthesis, proliferation, and protein synthesis. Treatment with polyamine precursors decreased (p < 0.05) the abundance of mRNA involved in proliferation and protein synthesis. Overall, C2C12 and Sol8 myoblasts do not differ (p > 0.10) in proliferation, protein synthesis, or mRNA abundance at the time points assessed. Furthermore, anabolic hormones, polyamines, and polyamine precursors increase proliferation and protein synthesis, and polyamines and their precursors alter the abundance of mRNA involved in growth.