Increased glucocorticoid/androgen receptor ratios in denervated striated muscle

Abstract

Cytosolic glucocorticoid (GR) and androgen receptors (AR) were evaluated at varying time intervals (1–28 days) post-denervation in rat bulbocavemosus/levator ani muscles and the receptor content in the unilaterally denervated muscles compared to the contralateral innervated muscles. Rats were adrenalectomized 3 days prior to GR or castrated 24 h prior to AR determinations. Receptor analyses were performed using charcoal adsorption. Lowered AR were noted in the denervated muscles during very early time periods post-denervation while increased GR were not observed until later. During later post-denervation intervals relative increases or decreases in receptors were dependent on the basis of data expression (cytosolic protein or DNA). The GR to AR ratio was consistently higher in denervated muscles regardless of the basis of comparison, however. We conclude that decreased responsiveness to anabolic stimuli may play a role in the atrophic process.