Glucocorticoid sites in skeletal muscle: adrenalectomy, maturation, fiber type, and sex

The glucocorticoid receptor population in skeletal muscle of the rat was examined. Data are included that address the following: tissue preparation, receptor stabilization, method of assay and analysis, cross-reactivity of a large variety of steroids, time to equilibrium, and the effect of adrenalectomy on the number of sites as well as the apparent binding affinity. In addition, we have observed the following: 1) an exponential decline in the concentration of sites from 27 to 160 days after birth; 2) a significantly higher concentration of sites in muscle from male animals as compared with female animals; and 3) a significantly higher concentration of sites in the slow-fiber soleus muscle as compared with the fast-fiber extensor digitorum longus muscle.