Increased association of ribosomes with myofibrils during the skeletal-muscle hypertrophy induced either by the beta-adrenoceptor agonist clenbuterol or by tenotomy.

Ribosome distribution in skeletal-muscle myofibres was investigated by immunohistochemistry and microdensitometry by using anti-(60 S ribosomal subunit) antibodies. Administration of the beta-adrenoceptor agonist clenbuterol caused an increase in the staining of the myofibrillar region with this antibody relative to that found in the subsarcolemmal cytoplasm. A similar effect was observed during hypertrophy of the plantaris muscle following severance of the tendon to the gastrocnemius. The results suggest that increased association of ribosomes with the myofibrils occurs during muscle hypertrophy.