PSIV-A-12 - Effects of Treating Primary Bovine Satellite Cells Cultures Inducted to Differentiate with Steroid Hormones, Zinc or Manganese on Creatine Kinase Activity

Abstract: Anabolic implants containing estradiol (E2) and trenbolone acetate (TBA) promote skeletal muscle growth by increasing protein synthesis of primary bovine satellite cells (BSC). Recent data indicate skeletal muscle growth induced by anabolic implants may be positively augmented by trace mineral (TM) supplementation. Currently, the effects that E2, TBA or TM have on differentiation of primary BSC cultures is unknown. The objective of this study was to determine whether BSC differentiation is altered when cultures are treated with E2, TBA, zinc (Zn) or manganese (Mn). Primary BSC were grown to 80% confluency and treated (n=2) with 3% horse serum (CON), 10 nM TBA, 10 nM E2, 10 nM TBA and 10 nM E2, or 0.05, 0.10 or 0.25 μM of Mn, or 10, 20 or 40 μM of Zn. Creatine kinase activity was measured at 0, 24 and 72 h post-treatment to assess BSC differentiation. Creatine kinase is a muscle specific enzyme that is upregulated during satellite cell differentiation. A series of contrasts were constructed to compare CON and treated cultures at each time point. Creatine kinase activity increased (P< 0.05) over time indicating all cultures were differentiating. There was no difference (P >0.10) between the CON and any of the treatments at either 0 or 24 h post-differentiation. Treatment with 10 nM TBA increased (P=0.03) creatine kinase activity at 72 h compared to CON cultures. However, treatment with Zn, Mn, E2 or E2 and TBA did not have an effect (P >0.15) on BSC differentiation as measured by creatine kinase activity. This preliminary data indicates TBA might increase BSC differentiation, but further experiments are needed to validate this finding. Further, additional research analyzing the impacts of Zn and Mn in the presence of different steroid hormones is warranted to better understand the relationship that exists between steroid hormones and TM.