In skeletal muscle, studies with animals have demonstrated that sex and estrogen may potentially influence muscle contractile properties and attenuate indices of post-exercise muscle damage, including the release of creatine kinase into the bloodstream and activity of the intramuscular lysosomal acid hydrolase, beta-glucuronidase. (Enns. 2010)They also highlight that
estrogen has also been shown to play a significant role in stimulating muscle repair and regenerative processes, including the activation and proliferation of satellite cells. (Enns. 2010)The proliferation of satellite cells is however what most bodybuilders are striving for. This is the process behind muscle hypertrophy and some scientists think that it is also the beginning of muscle hyperplasia, i.e. an actual increase in the amount of muscle fibers.
Thus, although the "mechanisms by which estrogen exerts its influence upon indices of skeletal muscle damage, inflammation and repair have not been fully elucidated" even hobby athletes must not overlook its potential protective effects, which are
- estrogen's action as an antioxidant
- estrogen's acting as a membrane stabilizer by intercalating within membrane phospholipids
- estrogen's role in the regulation of a number of downstream genes and molecular targets.
|Figure 1: Effect of E2 concentration on protein synthesis rate in fused bovine satellite cell cultures. Cultures were treated with serum free medium (SFM) or with SFM plus the indicated amounts of E2. (Kamanga-Sollo. 2010. Figure 1)|