Expression pattern of growth differentiation factor 8 during denervative atrophy of the gastrocnemius

Objective To analyze expression pattern of growth differentiation factor 8 (GDF8) during denervative atrophy of the gastrocnemius and discuss its potential role in atrophy of the gastrocnemius. Methods Levels of GDF8 mRNA and protein in the gastrocnemius at different time after denervation were detected by real time fluorescence quantitative polymerase chain reaction (PCR) and Western Blotting, respectively. The ratio of muscle wet weight, cross section area (μm2) and morphology of myofiber were also analyzed for comparison. Results At the early stage (3-7 days after denervation), GDF8 mRNA rather than protein level in the gastrocnemius increased instantly and decreased thereafter. Seven days after denervation, the levels of both GDF8 mRNA and protein again increased gradually, reached peak at day 28 and then decreased significantly at day 56 after denervation. Conclusions The denervative atrophy of the gastrocnemius is negatively correlated with increase of levels of GDF8 and protein, indicating that GDF8 plays an important role in denervative atrophy of the gastrocnemius, as provides a theoretical basis for further understanding the molecular mechanism of muscle atrophy and seeking corresponding treatment protocols.