You’ll see that, in addition to any androgen binding to GR, you’ll have two potent anti-catabolic factors:
mTOR and PGC-1α; GR negatively regulates both
To put it very simply, REDD1 negatively regulates mTOR, and FOXO1 is largely regulated by PGC-1α. Although they function “separately,” they can converge since REDD1 not only inhibits mTOR but also increases FOXO1.
You can make them resistant to catabolism by inhibiting FOXO1, and abolish the effects of GCs by inhibiting REDD1.
Not surprisingly, type 1 fibers—rich in mitochondria and OXPHOS—are resistant to stress-induced atrophy (glucocorticoids, energy deprivation, etc.) but are also resistant to hypertrophy.
Glycolytic fibers, on the other hand, which are prone to energy deficits because they have few mitochondria and rely on glycolysis, are sensitive to stress but are also sensitive to hypertrophy due to greater GR and AR density.
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